source: vendor/bash/3.1/builtins/alias.def

This file is alias.def, from which is created alias.c
It implements the builtins "alias" and "unalias" in Bash.

Copyright (C) 1987-2004 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

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for more details.

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$BUILTIN alias
$FUNCTION alias_builtin
$DEPENDS_ON ALIAS
$PRODUCES alias.c
$SHORT_DOC alias [-p] [name[=value] ... ]
`alias' with no arguments or with the -p option prints the list
of aliases in the form alias NAME=VALUE on standard output.
Otherwise, an alias is defined for each NAME whose VALUE is given.
A trailing space in VALUE causes the next word to be checked for
alias substitution when the alias is expanded.  Alias returns
true unless a NAME is given for which no alias has been defined.
$END

#include <config.h>

#if defined (ALIAS)

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

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

#  include <stdio.h>
#  include "../shell.h"
#  include "../alias.h"
#  include "common.h"
#  include "bashgetopt.h"

/* Flags for print_alias */
#define AL_REUSABLE     0x01

static void print_alias __P((alias_t *, int));

extern int posixly_correct;

/* Hack the alias command in a Korn shell way. */
int
alias_builtin (list)
     WORD_LIST *list;
{
  int any_failed, offset, pflag, dflags;
  alias_t **alias_list, *t;
  char *name, *value;

  dflags = posixly_correct ? 0 : AL_REUSABLE;
  pflag = 0;
  reset_internal_getopt ();
  while ((offset = internal_getopt (list, "p")) != -1)
    {
      switch (offset)
        {
        case 'p':
          pflag = 1;
          dflags |= AL_REUSABLE;
          break;
        default:
          builtin_usage ();
          return (EX_USAGE);
        }
    }

  list = loptend;

  if (list == 0 || pflag)
    {
      if (aliases == 0)
        return (EXECUTION_SUCCESS);

      alias_list = all_aliases ();

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

      for (offset = 0; alias_list[offset]; offset++)
        print_alias (alias_list[offset], dflags);

      free (alias_list);        /* XXX - Do not free the strings. */

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

  any_failed = 0;
  while (list)
    {
      name = list->word->word;

      for (offset = 0; name[offset] && name[offset] != '='; offset++)
        ;

      if (offset && name[offset] == '=')
        {
          name[offset] = '\0';
          value = name + offset + 1;

          if (legal_alias_name (name, 0) == 0)
            {
              builtin_error (_("`%s': invalid alias name"), name);
              any_failed++;
            }
          else
            add_alias (name, value);
        }
      else
        {
          t = find_alias (name);
          if (t)
            print_alias (t, dflags);
          else
            {
              sh_notfound (name);
              any_failed++;
            }
        }
      list = list->next;
    }

  return (any_failed ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
}
#endif /* ALIAS */

$BUILTIN unalias
$FUNCTION unalias_builtin
$DEPENDS_ON ALIAS
$SHORT_DOC unalias [-a] name [name ...]
Remove NAMEs from the list of defined aliases.  If the -a option is given,
then remove all alias definitions.
$END

#if defined (ALIAS)
/* Remove aliases named in LIST from the aliases database. */
int
unalias_builtin (list)
     register WORD_LIST *list;
{
  register alias_t *alias;
  int opt, aflag;

  aflag = 0;
  reset_internal_getopt ();
  while ((opt = internal_getopt (list, "a")) != -1)
    {
      switch (opt)
        {
        case 'a':
          aflag = 1;
          break;
        default:
          builtin_usage ();
          return (EX_USAGE);
        }
    }

  list = loptend;

  if (aflag)
    {
      delete_all_aliases ();
      return (EXECUTION_SUCCESS);
    }

  if (list == 0)
    {
      builtin_usage ();
      return (EX_USAGE);
    }

  aflag = 0;
  while (list)
    {
      alias = find_alias (list->word->word);

      if (alias)
        remove_alias (alias->name);
      else
        {
          sh_notfound (list->word->word);
          aflag++;
        }

      list = list->next;
    }

  return (aflag ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
}

/* Output ALIAS in such a way as to allow it to be read back in. */
static void
print_alias (alias, flags)
     alias_t *alias;
     int flags;
{
  char *value;

  value = sh_single_quote (alias->value);
  if (flags & AL_REUSABLE)
    printf ("alias ");
  printf ("%s=%s\n", alias->name, value);
  free (value);

  fflush (stdout);
}
#endif /* ALIAS */