coreutils/lib/filemode.c

/* filemode.c -- make a string describing file modes
   Copyright (C) 1985, 1990, 1993, 1998-2000, 2004 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#if HAVE_CONFIG_H
# include <config.h>
#endif

#include <sys/types.h>
#include <sys/stat.h>

#include "filemode.h"
#include "stat-macros.h"


/* Set the 's' and 't' flags in file attributes string CHARS,
   according to the file mode BITS.  */

static void
setst (mode_t bits, char *chars)
{
  if (bits & S_ISUID)
    {
      if (chars[3] != 'x')
	/* Set-uid, but not executable by owner.  */
	chars[3] = 'S';
      else
	chars[3] = 's';
    }
  if (bits & S_ISGID)
    {
      if (chars[6] != 'x')
	/* Set-gid, but not executable by group.  */
	chars[6] = 'S';
      else
	chars[6] = 's';
    }
  if (bits & S_ISVTX)
    {
      if (chars[9] != 'x')
	/* Sticky, but not executable by others.  */
	chars[9] = 'T';
      else
	chars[9] = 't';
    }
}

/* Return a character indicating the type of file described by
   file mode BITS:
   'd' for directories
   'D' for doors
   'b' for block special files
   'c' for character special files
   'n' for network special files
   'm' for multiplexor files
   'M' for an off-line (regular) file
   'l' for symbolic links
   's' for sockets
   'p' for fifos
   'C' for contigous data files
   '-' for regular files
   '?' for any other file type.  */

static char
ftypelet (mode_t bits)
{
  if (S_ISBLK (bits))
    return 'b';
  if (S_ISCHR (bits))
    return 'c';
  if (S_ISDIR (bits))
    return 'd';
  if (S_ISREG (bits))
    return '-';
  if (S_ISFIFO (bits))
    return 'p';
  if (S_ISLNK (bits))
    return 'l';
  if (S_ISSOCK (bits))
    return 's';
  if (S_ISMPC (bits))
    return 'm';
  if (S_ISNWK (bits))
    return 'n';
  if (S_ISDOOR (bits))
    return 'D';
  if (S_ISCTG (bits))
    return 'C';

  /* The following two tests are for Cray DMF (Data Migration
     Facility), which is a HSM file system.  A migrated file has a
     `st_dm_mode' that is different from the normal `st_mode', so any
     tests for migrated files should use the former.  */

  if (S_ISOFD (bits))
    /* off line, with data  */
    return 'M';
  /* off line, with no data  */
  if (S_ISOFL (bits))
    return 'M';
  return '?';
}

/* Like filemodestring, but only the relevant part of the `struct stat'
   is given as an argument.  */

void
mode_string (mode_t mode, char *str)
{
  str[0] = ftypelet (mode);
  str[1] = mode & S_IRUSR ? 'r' : '-';
  str[2] = mode & S_IWUSR ? 'w' : '-';
  str[3] = mode & S_IXUSR ? 'x' : '-';
  str[4] = mode & S_IRGRP ? 'r' : '-';
  str[5] = mode & S_IWGRP ? 'w' : '-';
  str[6] = mode & S_IXGRP ? 'x' : '-';
  str[7] = mode & S_IROTH ? 'r' : '-';
  str[8] = mode & S_IWOTH ? 'w' : '-';
  str[9] = mode & S_IXOTH ? 'x' : '-';
  setst (mode, str);
}

/* filemodestring - fill in string STR with an ls-style ASCII
   representation of the st_mode field of file stats block STATP.
   10 characters are stored in STR; no terminating null is added.
   The characters stored in STR are:

   0	File type.  'd' for directory, 'c' for character
	special, 'b' for block special, 'm' for multiplex,
	'l' for symbolic link, 's' for socket, 'p' for fifo,
	'-' for regular, '?' for any other file type

   1	'r' if the owner may read, '-' otherwise.

   2	'w' if the owner may write, '-' otherwise.

   3	'x' if the owner may execute, 's' if the file is
	set-user-id, '-' otherwise.
	'S' if the file is set-user-id, but the execute
	bit isn't set.

   4	'r' if group members may read, '-' otherwise.

   5	'w' if group members may write, '-' otherwise.

   6	'x' if group members may execute, 's' if the file is
	set-group-id, '-' otherwise.
	'S' if it is set-group-id but not executable.

   7	'r' if any user may read, '-' otherwise.

   8	'w' if any user may write, '-' otherwise.

   9	'x' if any user may execute, 't' if the file is "sticky"
	(will be retained in swap space after execution), '-'
	otherwise.
	'T' if the file is sticky but not executable.  */

void
filemodestring (struct stat *statp, char *str)
{
  mode_string (statp->st_mode, str);
}