Fix memory leaks reported by Lu Ming Yin.

Fixes for memory leaks reported by Lu Ming Yin, fixes from Howard Chu.

Add options to change the confirm key and default behaviour of
confirm-before. From Elias Assaf in GitHub issue 3548; prompted by an
earlier change from Yutaro Yoshii in GitHub issue 3496.

Expand command as a format, GitHub issue 2920.

Expand argument to run-shell again.

Validate command argument types (string or command list) and give more
useful error messages.

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Fixes for memory leaks reported by Lu Ming Yin, fixes from Howard Chu.

Add options to change the confirm key and default behaviour of
confirm-before. From Elias Assaf in GitHub issue 3548; prompted by an
earlier change from Yutaro Yoshii in GitHub issue 3496.

Expand command as a format, GitHub issue 2920.

Expand argument to run-shell again.

Validate command argument types (string or command list) and give more
useful error messages.

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Add options to change the confirm key and default behaviour of
confirm-before. From Elias Assaf in GitHub issue 3548; prompted by an
earlier change from Yutaro Yoshii in GitHub issue 3496.

Expand command as a format, GitHub issue 2920.

Expand argument to run-shell again.

Validate command argument types (string or command list) and give more
useful error messages.

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Expand command as a format, GitHub issue 2920.

Expand argument to run-shell again.

Validate command argument types (string or command list) and give more
useful error messages.

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Expand argument to run-shell again.

Validate command argument types (string or command list) and give more
useful error messages.

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Validate command argument types (string or command list) and give more
useful error messages.

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Move command argument parsing common functions and don't bother to parse
again if given a command rather than a string.

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.

Allow the initial context on prompts to be set with the new -I option to
command-prompt. From Tiago Cunha.

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.

The cursession member in struct cmd_ctx is always either curclient->session or
NULL when curclient is also NULL, so just eliminate it.

Switch the prompt code to return an empty string when the user enters no
response and reserve NULL for an explicit cancel. Change all callbacks to treat
them the same so no functional change.

Also add cancel key bindings to emacs mode which were missing.

Make all messages sent between the client and server fixed size.

This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.

As a side-effect this also removes a lot of now-unused command marshalling
code.

Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.

Nix a few unused attributes on arguments which are no longer unused.

Memory could be leaked if a second prompt or message appeared while another was
still present, so add a separate prompt free callback and make the _clear
function responsible for calling it if necessary (rather than the individual
prompt callbacks). Also make both messages and prompts clear any existing when
a new is set.

In addition, the screen could be modified while the prompt is there, restore
the redraw-entire-screen behaviour on prompt clear; add a comment as a
reminder.

Make status_message_set a variadic printf-like function. No functional change -
helpful for a couple of things coming soon.

Having fixed flags for single-character getopt options is a bit hard to
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.

This means new single character options can be used without the need to add it
explicitly to the list.

Import tmux, a terminal multiplexor allowing (among other things) a single
terminal to be switched between several different windows and programs
displayed on one terminal be detached from one terminal and moved to another.

ok deraadt pirofti

Add args parsing callback for some future work, currently unused.

Hide struct args behind a couple of accessor functions.

calloc for confirm-before data since the item needs to start NULL.

Set return code for confirm-before and make command-prompt also block,
GitHub issue 2822.

Make confirm-before optionally block the invoking client like run-shell,
GitHub issue 2819.

Add different command historys for different types of prompts
("command", "search" etc). From Anindya Mukherjee.

Expand target from client and use it to expand the prompt.

Make client -c and -t handling common in cmd-queue.c and try to be
clearer about whether the client is the target client (must have a
session) or not.

Add helpers for the simple case of parse string and add to command queue.

When adding a list of commands to the queue, instead of automatically
creating a new state for each group of commands, require the caller to
create one and use it for all the commands in the list. This means the
current target works even with list with multiple groups (which can
happen if they are defined with newlines).

Make struct cmd local to cmd.c and move it out of tmux.h.

Replace the split parser code (cfg.c and cmd-string.c) with a single
parser using yacc(1). This is a major change but is clearer and simpler
and allows some edge cases to be made more consistent, as well as
tidying up how aliases are handled. It will also allow some further
improvements later.

Entirely the same parser is now used for parsing the configuration file
and for string commands. This means that constructs previously only
available in .tmux.conf, such as %if, can now be used in string commands
(for example, those given to if-shell - not commands invoked from the
shell, they are still parsed by the shell itself).

The only syntax change I am aware of is that #{} outside quotes or a
comment is now considered a format and not a comment, so #{ is now a
syntax error (notably, if it is at the start of a line).

This also adds two new sections to the man page documenting the syntax
and outlining how parsing and command execution works.

Thanks to everyone who sent me test configs (they still all parse
without errors - but this doesn't mean they still work as intended!).

Thanks to Avi Halachmi for testing and man page improvements, also to
jmc@ for reviewing the man page changes.

Replace the various identical error callbacks with a single one in cmd-queue.c.

Tidy command prompt callbacks and pass in the client.

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.

It is silly for cmd_list_parse to return an integer error when it could
just return NULL.

Incremental search in copy mode (on for emacs keys by default) - much
the same as normal searching but updates the cursor position and marked
search terms as you type. C-r and C-s in the prompt repeat the search,
once finished searching (with Enter), N and n work as before.

Mass rename struct cmd_q to struct cmdq_item and related.

Rewrite command queue handling. Each client still has a command queue,
but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

Add static in cmd-* and fix a few other nits.

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.

Use member names in cmd_entry definitions so I stop getting confused
about the order.

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.

Change deref to the more sensible unref, and add a couple I missed before.

Instead of putting dead clients on a list and checking it every loop,
use event_once to queue a callback to deal with them. Also dead clients
with references would never actually be freed because the wrap-up
functions (the callback for stdin, or status_prompt_clear) would never
be called. So call them in server_client_lost.

Rewrite of tmux mouse support which was a mess. Instead of having
options for "mouse-this" and "mouse-that", mouse events may be bound as
keys and there is one option "mouse" that turns on mouse support
entirely (set -g mouse on).

See the new MOUSE SUPPORT section of the man page for description of the
key names and new flags (-t= to specify the pane or window under mouse
as a target, and send-keys -M to pass through a mouse event).

The default builtin bindings for the mouse are:

bind -n MouseDown1Pane select-pane -t=; send-keys -M
bind -n MouseDown1Status select-window -t=
bind -n MouseDrag1Pane copy-mode -M
bind -n MouseDrag1Border resize-pane -M

To get the effect of turning mode-mouse off, do:

unbind -n MouseDrag1Pane
unbind -temacs-copy MouseDrag1Pane

The old mouse options are now gone, set-option -q may be used to
suppress warnings if mixing configuration files.

Tidy up some includes.

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

Remove the barely-used and unnecessary command check() function.

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.

Fix error reporting for client commands by adding a flag to
cmd_find_client to tell it whether or not to show errors, sometimes it's
needed and sometimes not.

Need to set clients in context before changing their reference count.

Remove unnecessary initializers of cmd_ctx.

Add functions to allocate and free command contexts rather than doing it
all on the stack.

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.

xfree is not particularly helpful, remove it. From Thomas Adam.

Make confirm-before prompt customizable with -p option like
command-prompt. Also move responsibility for calling status_replace into
status_prompt_{set,update} and add #W and #P to the default kill-window
and kill-pane prompts. By Tiago Cunha.