lib/filemode.c

   1 /* filemode.c -- make a string describing file modes
   2    Copyright (C) 1985, 1990 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17 \f
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #ifndef S_IREAD
  21 #define S_IREAD S_IRUSR
  22 #define S_IWRITE S_IWUSR
  23 #define S_IEXEC S_IXUSR
  24 #endif
  25 #ifndef S_ISREG                 /* Doesn't have POSIX.1 stat stuff.  */
  26 #define mode_t unsigned short
  27 #endif
  28 #if !defined(S_ISBLK) && defined(S_IFBLK)
  29 #define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
  30 #endif
  31 #if !defined(S_ISCHR) && defined(S_IFCHR)
  32 #define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
  33 #endif
  34 #if !defined(S_ISDIR) && defined(S_IFDIR)
  35 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  36 #endif
  37 #if !defined(S_ISREG) && defined(S_IFREG)
  38 #define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
  39 #endif
  40 #if !defined(S_ISFIFO) && defined(S_IFIFO)
  41 #define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
  42 #endif
  43 #if !defined(S_ISLNK) && defined(S_IFLNK)
  44 #define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
  45 #endif
  46 #if !defined(S_ISSOCK) && defined(S_IFSOCK)
  47 #define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
  48 #endif
  49 #if !defined(S_ISMPB) && defined(S_IFMPB) /* V7 */
  50 #define S_ISMPB(m) (((m) & S_IFMT) == S_IFMPB)
  51 #define S_ISMPC(m) (((m) & S_IFMT) == S_IFMPC)
  52 #endif
  53 #if !defined(S_ISNWK) && defined(S_IFNWK) /* HP/UX */
  54 #define S_ISNWK(m) (((m) & S_IFMT) == S_IFNWK)
  55 #endif
  56
  57 void mode_string ();
  58 static char ftypelet ();
  59 static void rwx ();
  60 static void setst ();
  61
  62 /* filemodestring - fill in string STR with an ls-style ASCII
  63    representation of the st_mode field of file stats block STATP.
  64    10 characters are stored in STR; no terminating null is added.
  65    The characters stored in STR are:
  66
  67    0    File type.  'd' for directory, 'c' for character
  68         special, 'b' for block special, 'm' for multiplex,
  69         'l' for symbolic link, 's' for socket, 'p' for fifo,
  70         '-' for regular, '?' for any other file type
  71
  72    1    'r' if the owner may read, '-' otherwise.
  73
  74    2    'w' if the owner may write, '-' otherwise.
  75
  76    3    'x' if the owner may execute, 's' if the file is
  77         set-user-id, '-' otherwise.
  78         'S' if the file is set-user-id, but the execute
  79         bit isn't set.
  80
  81    4    'r' if group members may read, '-' otherwise.
  82
  83    5    'w' if group members may write, '-' otherwise.
  84
  85    6    'x' if group members may execute, 's' if the file is
  86         set-group-id, '-' otherwise.
  87         'S' if it is set-group-id but not executable.
  88
  89    7    'r' if any user may read, '-' otherwise.
  90
  91    8    'w' if any user may write, '-' otherwise.
  92
  93    9    'x' if any user may execute, 't' if the file is "sticky"
  94         (will be retained in swap space after execution), '-'
  95         otherwise.
  96         'T' if the file is sticky but not executable.  */
  97
  98 void
  99 filemodestring (statp, str)
 100      struct stat *statp;
 101      char *str;
 102 {
 103   mode_string (statp->st_mode, str);
 104 }
 105
 106 /* Like filemodestring, but only the relevant part of the `struct stat'
 107    is given as an argument.  */
 108
 109 void
 110 mode_string (mode, str)
 111      unsigned short mode;
 112      char *str;
 113 {
 114   str[0] = ftypelet (mode);
 115   rwx ((mode & 0700) << 0, &str[1]);
 116   rwx ((mode & 0070) << 3, &str[4]);
 117   rwx ((mode & 0007) << 6, &str[7]);
 118   setst (mode, str);
 119 }
 120
 121 /* Return a character indicating the type of file described by
 122    file mode BITS:
 123    'd' for directories
 124    'b' for block special files
 125    'c' for character special files
 126    'm' for multiplexor files
 127    'l' for symbolic links
 128    's' for sockets
 129    'p' for fifos
 130    '-' for regular files
 131    '?' for any other file type.  */
 132
 133 static char
 134 ftypelet (bits)
 135      mode_t bits;
 136 {
 137 #ifdef S_ISBLK
 138   if (S_ISBLK (bits))
 139     return 'b';
 140 #endif
 141   if (S_ISCHR (bits))
 142     return 'c';
 143   if (S_ISDIR (bits))
 144     return 'd';
 145   if (S_ISREG (bits))
 146     return '-';
 147 #ifdef S_ISFIFO
 148   if (S_ISFIFO (bits))
 149     return 'p';
 150 #endif
 151 #ifdef S_ISLNK
 152   if (S_ISLNK (bits))
 153     return 'l';
 154 #endif
 155 #ifdef S_ISSOCK
 156   if (S_ISSOCK (bits))
 157     return 's';
 158 #endif
 159 #ifdef S_ISMPC
 160   if (S_ISMPC (bits))
 161     return 'm';
 162 #endif
 163 #ifdef S_ISNWK
 164   if (S_ISNWK (bits))
 165     return 'n';
 166 #endif
 167   return '?';
 168 }
 169
 170 /* Look at read, write, and execute bits in BITS and set
 171    flags in CHARS accordingly.  */
 172
 173 static void
 174 rwx (bits, chars)
 175      unsigned short bits;
 176      char *chars;
 177 {
 178   chars[0] = (bits & S_IREAD) ? 'r' : '-';
 179   chars[1] = (bits & S_IWRITE) ? 'w' : '-';
 180   chars[2] = (bits & S_IEXEC) ? 'x' : '-';
 181 }
 182
 183 /* Set the 's' and 't' flags in file attributes string CHARS,
 184    according to the file mode BITS.  */
 185
 186 static void
 187 setst (bits, chars)
 188      unsigned short bits;
 189      char *chars;
 190 {
 191 #ifdef S_ISUID
 192   if (bits & S_ISUID)
 193     {
 194       if (chars[3] != 'x')
 195         /* Set-uid, but not executable by owner.  */
 196         chars[3] = 'S';
 197       else
 198         chars[3] = 's';
 199     }
 200 #endif
 201 #ifdef S_ISGID
 202   if (bits & S_ISGID)
 203     {
 204       if (chars[6] != 'x')
 205         /* Set-gid, but not executable by group.  */
 206         chars[6] = 'S';
 207       else
 208         chars[6] = 's';
 209     }
 210 #endif
 211 #ifdef S_ISVTX
 212   if (bits & S_ISVTX)
 213     {
 214       if (chars[9] != 'x')
 215         /* Sticky, but not executable by others.  */
 216         chars[9] = 'T';
 217       else
 218         chars[9] = 't';
 219     }
 220 #endif
 221 }