Bash-4.2 distribution sources and documentation

[thirdparty/bash.git] / builtins / test.def

This file is test.def, from which is created test.c.
It implements the builtin "test" in Bash.

Copyright (C) 1987-2010 Free Software Foundation, Inc.

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

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it under the terms of the GNU General Public License as published by
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You should have received a copy of the GNU General Public License
along with Bash.  If not, see <http://www.gnu.org/licenses/>.

$PRODUCES test.c

$BUILTIN test
$FUNCTION test_builtin
$SHORT_DOC test [expr]
Evaluate conditional expression.

Exits with a status of 0 (true) or 1 (false) depending on
the evaluation of EXPR.  Expressions may be unary or binary.  Unary
expressions are often used to examine the status of a file.  There
are string operators and numeric comparison operators as well.

The behavior of test depends on the number of arguments.  Read the
bash manual page for the complete specification.

File operators:

  -a FILE        True if file exists.
  -b FILE        True if file is block special.
  -c FILE        True if file is character special.
  -d FILE        True if file is a directory.
  -e FILE        True if file exists.
  -f FILE        True if file exists and is a regular file.
  -g FILE        True if file is set-group-id.
  -h FILE        True if file is a symbolic link.
  -L FILE        True if file is a symbolic link.
  -k FILE        True if file has its `sticky' bit set.
  -p FILE        True if file is a named pipe.
  -r FILE        True if file is readable by you.
  -s FILE        True if file exists and is not empty.
  -S FILE        True if file is a socket.
  -t FD          True if FD is opened on a terminal.
  -u FILE        True if the file is set-user-id.
  -w FILE        True if the file is writable by you.
  -x FILE        True if the file is executable by you.
  -O FILE        True if the file is effectively owned by you.
  -G FILE        True if the file is effectively owned by your group.
  -N FILE        True if the file has been modified since it was last read.

  FILE1 -nt FILE2  True if file1 is newer than file2 (according to
                   modification date).

  FILE1 -ot FILE2  True if file1 is older than file2.

  FILE1 -ef FILE2  True if file1 is a hard link to file2.

String operators:

  -z STRING      True if string is empty.

  -n STRING
     STRING      True if string is not empty.

  STRING1 = STRING2
                 True if the strings are equal.
  STRING1 != STRING2
                 True if the strings are not equal.
  STRING1 < STRING2
                 True if STRING1 sorts before STRING2 lexicographically.
  STRING1 > STRING2
                 True if STRING1 sorts after STRING2 lexicographically.

Other operators:

  -o OPTION      True if the shell option OPTION is enabled.
  -v VAR	 True if the shell variable VAR is set
  ! EXPR         True if expr is false.
  EXPR1 -a EXPR2 True if both expr1 AND expr2 are true.
  EXPR1 -o EXPR2 True if either expr1 OR expr2 is true.

  arg1 OP arg2   Arithmetic tests.  OP is one of -eq, -ne,
                 -lt, -le, -gt, or -ge.

Arithmetic binary operators return true if ARG1 is equal, not-equal,
less-than, less-than-or-equal, greater-than, or greater-than-or-equal
than ARG2.

Exit Status:
Returns success if EXPR evaluates to true; fails if EXPR evaluates to
false or an invalid argument is given.
$END

$BUILTIN [
$DOCNAME test_bracket
$FUNCTION test_builtin
$SHORT_DOC [ arg... ]
Evaluate conditional expression.

This is a synonym for the "test" builtin, but the last argument must
be a literal `]', to match the opening `['.
$END

#include <config.h>

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

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

#include "../shell.h"
#include "../test.h"
#include "common.h"

extern char *this_command_name;

/* TEST/[ builtin. */
int
test_builtin (list)
     WORD_LIST *list;
{
  char **argv;
  int argc, result;

  /* We let Matthew Bradburn and Kevin Braunsdorf's code do the
     actual test command.  So turn the list of args into an array
     of strings, since that is what their code wants. */
  if (list == 0)
    {
      if (this_command_name[0] == '[' && !this_command_name[1])
	{
	  builtin_error (_("missing `]'"));
	  return (EX_BADUSAGE);
	}

      return (EXECUTION_FAILURE);
    }

  argv = make_builtin_argv  (list, &argc);
  result = test_command (argc, argv);
  free ((char *)argv);

  return (result);
}