/* filemode.c -- make a string describing file modes
   Copyright (C) 1985, 1990 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 1, 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* MS-DOS port (c) 1990 by Thorsten Ohl, ohl@gnu.ai.mit.edu
   This port is also distributed under the terms of the
   GNU General Public License as published by the
   Free Software Foundation.

   Please note that this file is not identical to the
   original GNU release, you should have received this
   code as patch to the official release.

   $Header: e:/gnu/fileutil/RCS/filemode.c 1.4.0.1 90/09/17 08:18:12 tho Exp $
 */

#include <sys/types.h>
#include <sys/stat.h>
#ifdef _POSIX_SOURCE
#define S_IREAD S_IRUSR
#define S_IWRITE S_IWUSR
#define S_IEXEC S_IXUSR
#endif

#ifdef MSDOS
extern void filemodestring (struct stat *, char *);
extern void mode_string (unsigned short mode, char *str);
static char ftypelet (unsigned short bits);
static void rwx (unsigned short, char *);
static void setst (unsigned short, char *);
#else /* not MSDOS */
void mode_string ();
static char ftypelet ();
static void rwx ();
static void setst ();
#endif /* not MSDOS */

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

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

void
mode_string (mode, str)
     unsigned short mode;
     char *str;
{
  str[0] = ftypelet (mode);
  rwx ((mode & 0700) << 0, &str[1]);
  rwx ((mode & 0070) << 3, &str[4]);
  rwx ((mode & 0007) << 6, &str[7]);
  setst (mode, str);
}

/* Return a character indicating the type of file described by
   file mode BITS:
   'd' for directories
   'b' for block special files
   'c' for character special files
   'm' for multiplexor files
   'l' for symbolic links
   's' for sockets
   'p' for fifos
   '-' for regular files
   '?' for any other file type. */

static char
ftypelet (bits)
     unsigned short bits;
{
  switch (bits & S_IFMT)
    {
    default:
      return '?';
    case S_IFREG:
      return '-';
    case S_IFDIR:
      return 'd';
#ifdef S_IFLNK
    case S_IFLNK:
      return 'l';
#endif
#ifdef S_IFCHR
    case S_IFCHR:
      return 'c';
#endif
#ifdef S_IFBLK
    case S_IFBLK:
      return 'b';
#endif
#ifdef S_IFMPC
    case S_IFMPC:
    case S_IFMPB:
      return 'm';
#endif
#ifdef S_IFSOCK
    case S_IFSOCK:
      return 's';
#endif
#ifdef S_IFIFO
#if S_IFIFO != S_IFSOCK
    case S_IFIFO:
      return 'p';
#endif
#endif
#ifdef S_IFNWK			/* HP-UX */
    case S_IFNWK:
      return 'n';
#endif
    }
}

/* Look at read, write, and execute bits in BITS and set
   flags in CHARS accordingly. */

static void
rwx (bits, chars)
     unsigned short bits;
     char *chars;
{
  chars[0] = (bits & S_IREAD) ? 'r' : '-';
  chars[1] = (bits & S_IWRITE) ? 'w' : '-';
  chars[2] = (bits & S_IEXEC) ? 'x' : '-';
}

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

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