lib/mkdir.c

   1 /* BSD compatible make directory function for System V
   2    Copyright (C) 1988, 1990, 1998 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 Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 #if HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <errno.h>
  25 #ifndef errno
  26 extern int errno;
  27 #endif
  28
  29 #if STAT_MACROS_BROKEN
  30 # undef S_ISDIR
  31 #endif
  32
  33 #if !defined(S_ISDIR) && defined(S_IFDIR)
  34 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  35 #endif
  36
  37 #ifndef S_IRWXU
  38 # define S_IRWXU 0700
  39 #endif
  40 #ifndef S_IRWXG
  41 # define S_IRWXG 0070
  42 #endif
  43 #ifndef S_IRWXO
  44 # define S_IRWXO 0007
  45 #endif
  46
  47 /* mkdir adapted from GNU tar.  */
  48
  49 /* Make directory DPATH, with permission mode DMODE.
  50
  51    Written by Robert Rother, Mariah Corporation, August 1985
  52    (sdcsvax!rmr or rmr@uscd).  If you want it, it's yours.
  53
  54    Severely hacked over by John Gilmore to make a 4.2BSD compatible
  55    subroutine.  11Mar86; hoptoad!gnu
  56
  57    Modified by rmtodd@uokmax 6-28-87 -- when making an already existing dir,
  58    subroutine didn't return EEXIST.  It does now.  */
  59
  60 int
  61 mkdir (const char *dpath, mode_t dmode)
  62 {
  63   pid_t cpid;
  64   mode_t mode;
  65   int status;
  66   struct stat statbuf;
  67
  68   if (stat (dpath, &statbuf) == 0)
  69     {
  70       errno = EEXIST;           /* stat worked, so it already exists.  */
  71       return -1;
  72     }
  73
  74   /* If stat fails for a reason other than non-existence, return error.  */
  75   if (errno != ENOENT)
  76     return -1;
  77
  78   cpid = fork ();
  79   switch (cpid)
  80     {
  81     case -1:                    /* Cannot fork.  */
  82       return -1;                /* errno is already set.  */
  83
  84     case 0:                     /* Child process.  */
  85       /* Cheap hack to set mode of new directory.  Since this child
  86          process is going away anyway, we zap its umask.
  87          This won't suffice to set SUID, SGID, etc. on this
  88          directory, so the parent process calls chmod afterward.  */
  89       mode = umask (0); /* Get current umask.  */
  90       /* Set for mkdir.  */
  91       umask (mode | ((S_IRWXU | S_IRWXG | S_IRWXO) & ~dmode));
  92       execl ("/bin/mkdir", "mkdir", dpath, (char *) 0);
  93       _exit (1);
  94
  95     default:                    /* Parent process.  */
  96       /* Wait for kid to finish.  */
  97       while (wait (&status) != cpid)
  98         /* Do nothing.  */ ;
  99
 100       if (status)
 101         {
 102           /* /bin/mkdir failed.  */
 103           errno = EIO;
 104           return -1;
 105         }
 106       return chmod (dpath, dmode);
 107     }
 108 }