bash-3.2/builtins/pushd.c

/* pushd.c, created from pushd.def. */
#line 23 "pushd.def"

#line 48 "pushd.def"

#line 70 "pushd.def"

#line 93 "pushd.def"

#include <config.h>

#if defined (PUSHD_AND_POPD)
#include <stdio.h>
#ifndef _MINIX
#  include <sys/param.h>
#endif

#if defined (HAVE_UNISTD_H)
#  ifdef _MINIX
#    include <sys/types.h>
#  endif
#  include <unistd.h>
#endif

#include "../bashansi.h"
#include "../bashintl.h"

#include <errno.h>

#include <tilde/tilde.h>

#include "../shell.h"
#include "maxpath.h"
#include "common.h"
#include "builtext.h"

#ifdef LOADABLE_BUILTIN
#  include "builtins.h"
#endif

#if !defined (errno)
extern int errno;
#endif /* !errno */

/* The list of remembered directories. */
static char **pushd_directory_list = (char **)NULL;

/* Number of existing slots in this list. */
static int directory_list_size;

/* Offset to the end of the list. */
static int directory_list_offset;

static void pushd_error __P((int, char *));
static void clear_directory_stack __P((void));
static int cd_to_string __P((char *));
static int change_to_temp __P((char *));
static void add_dirstack_element __P((char *));
static int get_dirstack_index __P((intmax_t, int, int *));

#define NOCD		0x01
#define ROTATE		0x02
#define LONGFORM	0x04
#define CLEARSTAK	0x08

int
pushd_builtin (list)
     WORD_LIST *list;
{
  WORD_LIST *orig_list;
  char *temp, *current_directory, *top;
  int j, flags, skipopt;
  intmax_t num;
  char direction;

  orig_list = list;
  if (list && list->word && ISOPTION (list->word->word, '-'))
    {
      list = list->next;
      skipopt = 1;
    }
  else
    skipopt = 0;

  /* If there is no argument list then switch current and
     top of list. */
  if (list == 0)
    {
      if (directory_list_offset == 0)
	{
	  builtin_error (_("no other directory"));
	  return (EXECUTION_FAILURE);
	}

      current_directory = get_working_directory ("pushd");
      if (current_directory == 0)
	return (EXECUTION_FAILURE);

      j = directory_list_offset - 1;
      temp = pushd_directory_list[j];
      pushd_directory_list[j] = current_directory;
      j = change_to_temp (temp);
      free (temp);
      return j;
    }

  for (flags = 0; skipopt == 0 && list; list = list->next)
    {
      if (ISOPTION (list->word->word, 'n'))
	{
	  flags |= NOCD;
	}
      else if (ISOPTION (list->word->word, '-'))
	{
	  list = list->next;
	  break;
	}
      else if (list->word->word[0] == '-' && list->word->word[1] == '\0')
	/* Let `pushd -' work like it used to. */
	break;
      else if (((direction = list->word->word[0]) == '+') || direction == '-')
	{
	  if (legal_number (list->word->word + 1, &num) == 0)
	    {
	      sh_invalidnum (list->word->word);
	      builtin_usage ();
	      return (EXECUTION_FAILURE);
	    }

	  if (direction == '-')
	    num = directory_list_offset - num;

	  if (num > directory_list_offset || num < 0)
	    {
	      pushd_error (directory_list_offset, list->word->word);
	      return (EXECUTION_FAILURE);
	    }
	  flags |= ROTATE;
	}
      else if (*list->word->word == '-')
	{
	  sh_invalidopt (list->word->word);
	  builtin_usage ();
	  return (EXECUTION_FAILURE);
	}
      else
	break;
    }

  if (flags & ROTATE)
    {
      /* Rotate the stack num times.  Remember, the current
	 directory acts like it is part of the stack. */
      temp = get_working_directory ("pushd");

      if (num == 0)
	{
	  j = ((flags & NOCD) == 0) ? change_to_temp (temp) : EXECUTION_SUCCESS;
	  free (temp);
	  return j;
	}

      do
	{
	  top = pushd_directory_list[directory_list_offset - 1];

	  for (j = directory_list_offset - 2; j > -1; j--)
	    pushd_directory_list[j + 1] = pushd_directory_list[j];

	  pushd_directory_list[j + 1] = temp;

	  temp = top;
	  num--;
	}
      while (num);

      j = ((flags & NOCD) == 0) ? change_to_temp (temp) : EXECUTION_SUCCESS;
      free (temp);
      return j;
    }

  if (list == 0)
    return (EXECUTION_SUCCESS);

  /* Change to the directory in list->word->word.  Save the current
     directory on the top of the stack. */
  current_directory = get_working_directory ("pushd");
  if (current_directory == 0)
    return (EXECUTION_FAILURE);

  j = ((flags & NOCD) == 0) ? cd_builtin (skipopt ? orig_list : list) : EXECUTION_SUCCESS;
  if (j == EXECUTION_SUCCESS)
    {
      add_dirstack_element ((flags & NOCD) ? savestring (list->word->word) : current_directory);
      dirs_builtin ((WORD_LIST *)NULL);
      if (flags & NOCD)
	free (current_directory);
      return (EXECUTION_SUCCESS);
    }
  else
    {
      free (current_directory);
      return (EXECUTION_FAILURE);
    }
}

/* Pop the directory stack, and then change to the new top of the stack.
   If LIST is non-null it should consist of a word +N or -N, which says
   what element to delete from the stack.  The default is the top one. */
int
popd_builtin (list)
     WORD_LIST *list;
{
  register int i;
  intmax_t which;
  int flags;
  char direction;
  char *which_word;

  which_word = (char *)NULL;
  for (flags = 0, which = 0, direction = '+'; list; list = list->next)
    {
      if (ISOPTION (list->word->word, 'n'))
	{
	  flags |= NOCD;
	}
      else if (ISOPTION (list->word->word, '-'))
	{
	  list = list->next;
	  break;
	}
      else if (((direction = list->word->word[0]) == '+') || direction == '-')
	{
	  if (legal_number (list->word->word + 1, &which) == 0)
	    {
	      sh_invalidnum (list->word->word);
	      builtin_usage ();
	      return (EXECUTION_FAILURE);
	    }
	  which_word = list->word->word;
	}
      else if (*list->word->word == '-')
	{
	  sh_invalidopt (list->word->word);
	  builtin_usage ();
	  return (EXECUTION_FAILURE);
	}
      else
	break;
    }

  if (which > directory_list_offset || (directory_list_offset == 0 && which == 0))
    {
      pushd_error (directory_list_offset, which_word ? which_word : "");
      return (EXECUTION_FAILURE);
    }

  /* Handle case of no specification, or top of stack specification. */
  if ((direction == '+' && which == 0) ||
      (direction == '-' && which == directory_list_offset))
    {
      i = ((flags & NOCD) == 0) ? cd_to_string (pushd_directory_list[directory_list_offset - 1])
      				: EXECUTION_SUCCESS;
      if (i != EXECUTION_SUCCESS)
	return (i);
      free (pushd_directory_list[--directory_list_offset]);
    }
  else
    {
      /* Since an offset other than the top directory was specified,
	 remove that directory from the list and shift the remainder
	 of the list into place. */
      i = (direction == '+') ? directory_list_offset - which : which;
      free (pushd_directory_list[i]);
      directory_list_offset--;

      /* Shift the remainder of the list into place. */
      for (; i < directory_list_offset; i++)
	pushd_directory_list[i] = pushd_directory_list[i + 1];
    }

  dirs_builtin ((WORD_LIST *)NULL);
  return (EXECUTION_SUCCESS);
}

/* Print the current list of directories on the directory stack. */
int
dirs_builtin (list)
     WORD_LIST *list;
{
  int flags, desired_index, index_flag, vflag;
  intmax_t i;
  char *temp, *w;

  for (flags = vflag = index_flag = 0, desired_index = -1, w = ""; list; list = list->next)
    {
      if (ISOPTION (list->word->word, 'l'))
	{
	  flags |= LONGFORM;
	}
      else if (ISOPTION (list->word->word, 'c'))
	{
	  flags |= CLEARSTAK;
	}
      else if (ISOPTION (list->word->word, 'v'))
	{
	  vflag |= 2;
	}
      else if (ISOPTION (list->word->word, 'p'))
	{
	  vflag |= 1;
	}
      else if (ISOPTION (list->word->word, '-'))
	{
	  list = list->next;
	  break;
	}
      else if (*list->word->word == '+' || *list->word->word == '-')
	{
	  int sign;
	  if (legal_number (w = list->word->word + 1, &i) == 0)
	    {
	      sh_invalidnum (list->word->word);
	      builtin_usage ();
	      return (EXECUTION_FAILURE);
	    }
	  sign = (*list->word->word == '+') ? 1 : -1;
	  desired_index = get_dirstack_index (i, sign, &index_flag);
	}
      else
	{
	  sh_invalidopt (list->word->word);
	  builtin_usage ();
	  return (EXECUTION_FAILURE);
	}
    }

  if (flags & CLEARSTAK)
    {
      clear_directory_stack ();
      return (EXECUTION_SUCCESS);
    }

  if (index_flag && (desired_index < 0 || desired_index > directory_list_offset))
    {
      pushd_error (directory_list_offset, w);
      return (EXECUTION_FAILURE);
    }

#define DIRSTACK_FORMAT(temp) \
  (flags & LONGFORM) ? temp : polite_directory_format (temp)

  /* The first directory printed is always the current working directory. */
  if (index_flag == 0 || (index_flag == 1 && desired_index == 0))
    {
      temp = get_working_directory ("dirs");
      if (temp == 0)
	temp = savestring (_("<no current directory>"));
      if (vflag & 2)
	printf ("%2d  %s", 0, DIRSTACK_FORMAT (temp));
      else
	printf ("%s", DIRSTACK_FORMAT (temp));
      free (temp);
      if (index_flag)
	{
	  putchar ('\n');
	  return EXECUTION_SUCCESS;
	}
    }

#define DIRSTACK_ENTRY(i) \
  (flags & LONGFORM) ? pushd_directory_list[i] \
		     : polite_directory_format (pushd_directory_list[i])

  /* Now print the requested directory stack entries. */
  if (index_flag)
    {
      if (vflag & 2)
	printf ("%2d  %s", directory_list_offset - desired_index,
			   DIRSTACK_ENTRY (desired_index));
      else
	printf ("%s", DIRSTACK_ENTRY (desired_index));
    }
  else
    for (i = directory_list_offset - 1; i >= 0; i--)
      if (vflag >= 2)
	printf ("\n%2d  %s", directory_list_offset - (int)i, DIRSTACK_ENTRY (i));
      else
	printf ("%s%s", (vflag & 1) ? "\n" : " ", DIRSTACK_ENTRY (i));

  putchar ('\n');
  fflush (stdout);
  return (EXECUTION_SUCCESS);
}

static void
pushd_error (offset, arg)
     int offset;
     char *arg;
{
  if (offset == 0)
    builtin_error ("directory stack empty");
  else
    sh_erange (arg, "directory stack index");
}

static void
clear_directory_stack ()
{
  register int i;

  for (i = 0; i < directory_list_offset; i++)
    free (pushd_directory_list[i]);
  directory_list_offset = 0;
}

/* Switch to the directory in NAME.  This uses the cd_builtin to do the work,
   so if the result is EXECUTION_FAILURE then an error message has already
   been printed. */
static int
cd_to_string (name)
     char *name;
{
  WORD_LIST *tlist;
  WORD_LIST *dir;
  int result;

  dir = make_word_list (make_word (name), NULL);
  tlist = make_word_list (make_word ("--"), dir);
  result = cd_builtin (tlist);
  dispose_words (tlist);
  return (result);
}

static int
change_to_temp (temp)
     char *temp;
{
  int tt;

  tt = temp ? cd_to_string (temp) : EXECUTION_FAILURE;

  if (tt == EXECUTION_SUCCESS)
    dirs_builtin ((WORD_LIST *)NULL);

  return (tt);
}

static void
add_dirstack_element (dir)
     char *dir;
{
  if (directory_list_offset == directory_list_size)
    pushd_directory_list = strvec_resize (pushd_directory_list, directory_list_size += 10);
  pushd_directory_list[directory_list_offset++] = dir;
}

static int
get_dirstack_index (ind, sign, indexp)
     intmax_t ind;
     int sign, *indexp;
{
  if (indexp)
    *indexp = sign > 0 ? 1 : 2;

  /* dirs +0 prints the current working directory. */
  /* dirs -0 prints last element in directory stack */
  if (ind == 0 && sign > 0)
    return 0;
  else if (ind == directory_list_offset)
    {
      if (indexp)
	*indexp = sign > 0 ? 2 : 1;
      return 0;
    }
  else if (ind >= 0 && ind <= directory_list_offset)
    return (sign > 0 ? directory_list_offset - ind : ind);
  else
    return -1;
}

/* Used by the tilde expansion code. */
char *
get_dirstack_from_string (string)
     char *string;
{
  int ind, sign, index_flag;
  intmax_t i;

  sign = 1;
  if (*string == '-' || *string == '+')
    {
      sign = (*string == '-') ? -1 : 1;
      string++;
    }
  if (legal_number (string, &i) == 0)
    return ((char *)NULL);

  index_flag = 0;
  ind = get_dirstack_index (i, sign, &index_flag);
  if (index_flag && (ind < 0 || ind > directory_list_offset))
    return ((char *)NULL);
  if (index_flag == 0 || (index_flag == 1 && ind == 0))
    return (get_string_value ("PWD"));
  else
    return (pushd_directory_list[ind]);
}

#ifdef INCLUDE_UNUSED
char *
get_dirstack_element (ind, sign)
     intmax_t ind;
     int sign;
{
  int i;

  i = get_dirstack_index (ind, sign, (int *)NULL);
  return (i < 0 || i > directory_list_offset) ? (char *)NULL
					      : pushd_directory_list[i];
}
#endif

void
set_dirstack_element (ind, sign, value)
     intmax_t ind;
     int  sign;
     char *value;
{
  int i;

  i = get_dirstack_index (ind, sign, (int *)NULL);
  if (ind == 0 || i < 0 || i > directory_list_offset)
    return;
  free (pushd_directory_list[i]);
  pushd_directory_list[i] = savestring (value);
}

WORD_LIST *
get_directory_stack (flags)
     int flags;
{
  register int i;
  WORD_LIST *ret;
  char *d, *t;

  for (ret = (WORD_LIST *)NULL, i = 0; i < directory_list_offset; i++)
    {
      d = (flags&1) ? polite_directory_format (pushd_directory_list[i])
		    : pushd_directory_list[i];
      ret = make_word_list (make_word (d), ret);
    }
  /* Now the current directory. */
  d = get_working_directory ("dirstack");
  i = 0;	/* sentinel to decide whether or not to free d */
  if (d == 0)
    d = ".";
  else
    {
      t = polite_directory_format (d);
      /* polite_directory_format sometimes returns its argument unchanged.
	 If it does not, we can free d right away.  If it does, we need to
	 mark d to be deleted later. */
      if (t != d)
	{
	  free (d);
	  d = t;
	}
      else /* t == d, so d is what we want */
	i = 1;
    }
  ret = make_word_list (make_word (d), ret);
  if (i)
    free (d);
  return ret;	/* was (REVERSE_LIST (ret, (WORD_LIST *)); */
}

#ifdef LOADABLE_BUILTIN
char * const dirs_doc[] = {
  N_("Display the list of currently remembered directories.  Directories"),
  N_("find their way onto the list with the `pushd' command; you can get"),
  N_("back up through the list with the `popd' command."),
  N_(" "),
  N_("The -l flag specifies that `dirs' should not print shorthand versions"),
  N_("of directories which are relative to your home directory.  This means"),
  N_("that `~/bin' might be displayed as `/homes/bfox/bin'.  The -v flag"),
  N_("causes `dirs' to print the directory stack with one entry per line,"),
  N_("prepending the directory name with its position in the stack.  The -p"),
  N_("flag does the same thing, but the stack position is not prepended."),
  N_("The -c flag clears the directory stack by deleting all of the elements."),
  N_(" "),
  N_("+N   displays the Nth entry counting from the left of the list shown by"),
  N_("     dirs when invoked without options, starting with zero."),
  N_(" "),
  N_("-N   displays the Nth entry counting from the right of the list shown by"),
  N_("     dirs when invoked without options, starting with zero."),
  (char *)NULL
};

char * const pushd_doc[] = {
  N_("Adds a directory to the top of the directory stack, or rotates"),
  N_("the stack, making the new top of the stack the current working"),
  N_("directory.  With no arguments, exchanges the top two directories."),
  N_(" "),
  N_("+N   Rotates the stack so that the Nth directory (counting"),
  N_("     from the left of the list shown by `dirs', starting with"),
  N_("     zero) is at the top."),
  N_(" "),
  N_("-N   Rotates the stack so that the Nth directory (counting"),
  N_("     from the right of the list shown by `dirs', starting with"),
  N_("     zero) is at the top."),
  N_(" "),
  N_("-n   suppress the normal change of directory when adding directories"),
  N_("     to the stack, so only the stack is manipulated."),
  N_(" "),
  N_("dir  adds DIR to the directory stack at the top, making it the"),
  N_("     new current working directory."),
  N_(" "),
  N_("You can see the directory stack with the `dirs' command."),
  (char *)NULL
};

char * const popd_doc[] = {
  N_("Removes entries from the directory stack.  With no arguments,"),
  N_("removes the top directory from the stack, and cd's to the new"),
  N_("top directory."),
  N_(" "),
  N_("+N   removes the Nth entry counting from the left of the list"),
  N_("     shown by `dirs', starting with zero.  For example: `popd +0'"),
  N_("     removes the first directory, `popd +1' the second."),
  N_(" "),
  N_("-N   removes the Nth entry counting from the right of the list"),
  N_("     shown by `dirs', starting with zero.  For example: `popd -0'"),
  N_("     removes the last directory, `popd -1' the next to last."),
  N_(" "),
  N_("-n   suppress the normal change of directory when removing directories"),
  N_("     from the stack, so only the stack is manipulated."),
  N_(" "),
  N_("You can see the directory stack with the `dirs' command."),
  (char *)NULL
};

struct builtin pushd_struct = {
	"pushd",
	pushd_builtin,
	BUILTIN_ENABLED,
	pushd_doc,
	"pushd [+N | -N] [-n] [dir]",
	0
};

struct builtin popd_struct = {
	"popd",
	popd_builtin,
	BUILTIN_ENABLED,
	popd_doc,
	"popd [+N | -N] [-n]",
	0
};

struct builtin dirs_struct = {
	"dirs",
	dirs_builtin,
	BUILTIN_ENABLED,
	dirs_doc,
	"dirs [-clpv] [+N] [-N]",
	0
};
#endif /* LOADABLE_BUILTIN */

#endif /* PUSHD_AND_POPD */