lib/filemode.c

   1 /* filemode.c -- make a string describing file modes
   2
   3    Copyright (C) 1985, 1990, 1993, 1998-2000, 2004, 2006, 2009-2024 Free
   4    Software Foundation, Inc.
   5
   6    This program is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation, either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #include <config.h>
  20
  21 #include "filemode.h"
  22
  23 #if ! HAVE_DECL_STRMODE
  24
  25 /* Return a character indicating the type of file described by
  26    file mode BITS:
  27    '-' regular file
  28    'b' block special file
  29    'c' character special file
  30    'C' high performance ("contiguous data") file
  31    'd' directory
  32    'D' door
  33    'l' symbolic link
  34    'm' multiplexed file (7th edition Unix; obsolete)
  35    'n' network special file (HP-UX)
  36    'p' fifo (named pipe)
  37    'P' port
  38    's' socket
  39    'w' whiteout (4.4BSD)
  40    '?' some other file type  */
  41
  42 static char
  43 ftypelet (mode_t bits)
  44 {
  45   /* These are the most common, so test for them first.  */
  46   if (S_ISREG (bits))
  47     return '-';
  48   if (S_ISDIR (bits))
  49     return 'd';
  50
  51   /* Other letters standardized by POSIX 1003.1-2004.  */
  52   if (S_ISBLK (bits))
  53     return 'b';
  54   if (S_ISCHR (bits))
  55     return 'c';
  56   if (S_ISLNK (bits))
  57     return 'l';
  58   if (S_ISFIFO (bits))
  59     return 'p';
  60
  61   /* Other file types (though not letters) standardized by POSIX.  */
  62   if (S_ISSOCK (bits))
  63     return 's';
  64
  65   /* Nonstandard file types.  */
  66   if (S_ISCTG (bits))
  67     return 'C';
  68   if (S_ISDOOR (bits))
  69     return 'D';
  70   if (S_ISMPB (bits) || S_ISMPC (bits) || S_ISMPX (bits))
  71     return 'm';
  72   if (S_ISNWK (bits))
  73     return 'n';
  74   if (S_ISPORT (bits))
  75     return 'P';
  76   if (S_ISWHT (bits))
  77     return 'w';
  78
  79   return '?';
  80 }
  81
  82 /* Like filemodestring, but rely only on MODE.  */
  83
  84 void
  85 strmode (mode_t mode, char *str)
  86 {
  87   str[0] = ftypelet (mode);
  88   str[1] = mode & S_IRUSR ? 'r' : '-';
  89   str[2] = mode & S_IWUSR ? 'w' : '-';
  90   str[3] = (mode & S_ISUID
  91             ? (mode & S_IXUSR ? 's' : 'S')
  92             : (mode & S_IXUSR ? 'x' : '-'));
  93   str[4] = mode & S_IRGRP ? 'r' : '-';
  94   str[5] = mode & S_IWGRP ? 'w' : '-';
  95   str[6] = (mode & S_ISGID
  96             ? (mode & S_IXGRP ? 's' : 'S')
  97             : (mode & S_IXGRP ? 'x' : '-'));
  98   str[7] = mode & S_IROTH ? 'r' : '-';
  99   str[8] = mode & S_IWOTH ? 'w' : '-';
 100   str[9] = (mode & S_ISVTX
 101             ? (mode & S_IXOTH ? 't' : 'T')
 102             : (mode & S_IXOTH ? 'x' : '-'));
 103   str[10] = ' ';
 104   str[11] = '\0';
 105 }
 106
 107 #endif /* ! HAVE_DECL_STRMODE */
 108
 109 /* filemodestring - fill in string STR with an ls-style ASCII
 110    representation of the st_mode field of file stats block STATP.
 111    12 characters are stored in STR.
 112    The characters stored in STR are:
 113
 114    0    File type, as in ftypelet above, except that other letters are used
 115         for files whose type cannot be determined solely from st_mode:
 116
 117             'F' semaphore
 118             'Q' message queue
 119             'S' shared memory object
 120             'T' typed memory object
 121
 122    1    'r' if the owner may read, '-' otherwise.
 123
 124    2    'w' if the owner may write, '-' otherwise.
 125
 126    3    'x' if the owner may execute, 's' if the file is
 127         set-user-id, '-' otherwise.
 128         'S' if the file is set-user-id, but the execute
 129         bit isn't set.
 130
 131    4    'r' if group members may read, '-' otherwise.
 132
 133    5    'w' if group members may write, '-' otherwise.
 134
 135    6    'x' if group members may execute, 's' if the file is
 136         set-group-id, '-' otherwise.
 137         'S' if it is set-group-id but not executable.
 138
 139    7    'r' if any user may read, '-' otherwise.
 140
 141    8    'w' if any user may write, '-' otherwise.
 142
 143    9    'x' if any user may execute, 't' if the file is "sticky"
 144         (will be retained in swap space after execution), '-'
 145         otherwise.
 146         'T' if the file is sticky but not executable.
 147
 148    10   ' ' for compatibility with 4.4BSD strmode,
 149         since this interface does not support ACLs.
 150
 151    11   '\0'.  */
 152
 153 void
 154 filemodestring (struct stat const *statp, char *str)
 155 {
 156   strmode (statp->st_mode, str);
 157
 158   if (S_TYPEISSEM (statp))
 159     str[0] = 'F';
 160   else if (S_TYPEISMQ (statp))
 161     str[0] = 'Q';
 162   else if (S_TYPEISSHM (statp))
 163     str[0] = 'S';
 164   else if (S_TYPEISTMO (statp))
 165     str[0] = 'T';
 166 }