1# @(#)README 8.4 (Berkeley) 11/22/94
2
3Generally, all non-system error and informational messages in nvi are
4catalog messages, i.e. they can be tailored to a specific langauge.
5Command strings, usage strings, system errors and other "known text"
6are not. It would certainly be possible to internationalize all the
7text strings in nvi, but it's unclear that it's the right thing to do.
8
9First, there's no portable way to do message catalogs. The System V
10scheme is a reasonable choice, but none of the 4BSD derived systems
11support it. So, catalogs are completely implemented within nvi, and
12don't require any library support.
13
14Message catalogs in nvi are fairly simple. Every catalog message
15consists of two parts -- an initial number followed by a pipe (`|')
16character, followed by the English text for the message. For example:
17
18 msgq(sp, M_ERR, "001|This is an error message");
19
20would be a typical message.
21
22When the msgq() routine is called, if the user has specified a message
23catalog and the format string (the third argument) has a leading number,
24then it is converted to a record number, and that record is retrieved
25from the message catalog and used as a replacement format string. If
26the record can't be retrieved for any reason, the English text is displayed
27instead.
28
29Each message format string MUST map into the English format string, i.e.
30it can't display more or different arguments than the English one.
31
32For example:
33
34 msgq(sp, M_ERR, "002|Error: %d %x", arg1, arg2);
35
36is a format string that displays two arguments. It is possible, however,
37to reorder the arguments or to not display all of them. The convention
38nvi uses is the System V printf(3) convention, i.e. "%[0-9]*$" is the name
39of a specific, numbered argument. For example:
40
41 msgq(sp, M_ERR, "002|Error: %2$d %1$x", arg1, arg2);
42
43displays the arguments in reverse order.
44
45If the system supports this convention in its library printf routines
46(as specified by the test #define NL_ARGMAX), nvi uses those routines.
47Otherwise, there is some serious magic going on in common/msg.c to make
48this all work.
49
50Arguments to the msgq function are required to contain ONLY printable
51characters. No further translation is done by the msgq routine before
52displaying the message on the screen. For example, in the msgq call:
53
54 msgq(sp, M_ERR, "003|File: %s", file_name);
55
56"file_name" must contain only printable characters. The routine
57msg_print() returns a printable version of a string in allocated
58memory. For example:
59
60 char *p;
61
62 p = msg_print(sp, file_name);
63 msgq(sp, M_ERR, M("003", "File: %s"), p);
64 FREE_SPACE(sp, p, 0);
65
66makes sure that "file_name" is printable before calling the msgq
67routine.
68
69=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
70
71The message catalogs themselves are maintained in two files. The first
72is the "base file" which contains two fields, a record number and the
73message itself. All base files are named using the convention
74"vi_<language>.base", e.g. the English one is "vi_english.base". For
75example:
76
77 002 "Unable to create temporary file"
78 003 "Warning: %s is not a regular file"
79 004 "%s already locked, session is read-only"
80 005 "%s: remove"
81 006 "%s: close"
82 007 "%s: remove"
83 008 "%s: remove"
84 009 "Read-only file, not written; use ! to override"
85 010 "Read-only file, not written"
86
87are the first few lines of the current vi_english.base file. Note that
88message #1 is missing -- the first message of each catalog is a special
89one, so that nvi can recognize message catalog files. It's added by the
90Makefile script that creates the second version of the message catalog.
91
92The second file is the file used by nvi to access messages, and is a list
93of the messages, one per line:
94
95 VI_MESSAGE_CATALOG
96 Unable to create temporary fileX
97 Warning: %s is not a regular fileX
98 %s already locked, session is read-onlyX
99 %s: removeX
100 %s: closeX
101 %s: removeX
102 %s: removeX
103 Read-only file, not written; use ! to overrideX
104 Read-only file, not writtenX
105
106Note that all messages have had a trailing 'X' character appended. This
107is to provide nvi a place to store a trailing nul for the message so that
108C library routines that expect one won't be disappointed.
109
110These files are named for their language, e.g. "vi_english". The second
111files are automatically created from the first files.
112
113To create a new catalog for nvi:
114
115Copy the file vi_english.base to a file that you can modify , e.g. "cp
116vi_english.base vi_german.base". For each of the messages in the file,
117replace the message with the string that you want to use. To find out
118what the arguments to a message are, I'm afraid you'll have to search
119the source code for the message number. You can find them fairly quickly
120by doing:
121
122 cd ..; egrep '123\|' */*.[chys]
123
124I'm sorry that there's not an easier way, but I couldn't think of
125anything that wasn't a lot of work.
126
127If, for some reason, you don't have the file vi_english.base, or you
128have new sources for which you want to create a new base catalog, you
129can create it by running the command "make english" in the catalog
130directory.
131
132Once you've translated all of the strings, then add your catalog to the
133"CAT=" line of the Makefile, and run the command "make catalog". This
134will create the second (and corresponding) file for each file named
135<language>.base.
136
137Don't worry about missing line numbers, i.e. base files that look like:
138
139 005 Message number 5.
140 007 Message number 7.
141
142This simply means that a message was deleted during the course of nvi's
143development. It will be taken care of automatically when you create
144the second form of the file.
145
146=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
147If you add new messages to the nvi sources, you can check your work by
148doing "make english; make check". The "make check" target lists unused
149message numbers, duplicate message numbers, and duplicate messages.
150Unused message numbers are only useful if you are condensing messages.
151Duplicate message numbers are a serious problem and have to be fixed.
152Duplicate messages are only interesting if a message appears often enough
153that it's worth creating a routine so that the string is only need in
154a single place.
155
156=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
157To select a catalog when running nvi, set the "msgcat" option. If the
158value of this option ends with a '/', it is treated as the name of a
159directory that contains a message catalog "vi_XXXX", where XXXX is the
160value of the LANG environmental variable, if it's set, or the value of
161the LC_MESSAGES environmental variable if it's not. If neither of those
162environmental variables are set, or if the option doesn't end in a '/',
163the option is treated as the full path name of the message catalog to use.
164
165If any messages are missing from the catalog, the backup text (English)
166is used instead.
167