cups/tempfile.c

   1 /*
   2  * "$Id$"
   3  *
   4  * Temp file utilities for CUPS.
   5  *
   6  * Copyright 2007-2014 by Apple Inc.
   7  * Copyright 1997-2006 by Easy Software Products.
   8  *
   9  * These coded instructions, statements, and computer programs are the
  10  * property of Apple Inc. and are protected by Federal copyright
  11  * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  12  * which should have been included with this file.  If this file is
  13  * file is missing or damaged, see the license at "http://www.cups.org/".
  14  *
  15  * This file is subject to the Apple OS-Developed Software exception.
  16  */
  17
  18 /*
  19  * Include necessary headers...
  20  */
  21
  22 #include "cups-private.h"
  23 #include <stdlib.h>
  24 #include <fcntl.h>
  25 #include <sys/stat.h>
  26 #if defined(WIN32) || defined(__EMX__)
  27 #  include <io.h>
  28 #else
  29 #  include <unistd.h>
  30 #endif /* WIN32 || __EMX__ */
  31
  32
  33 /*
  34  * 'cupsTempFd()' - Creates a temporary file.
  35  *
  36  * The temporary filename is returned in the filename buffer.
  37  * The temporary file is opened for reading and writing.
  38  */
  39
  40 int                                     /* O - New file descriptor or -1 on error */
  41 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  42            int  len)                    /* I - Size of buffer */
  43 {
  44   int           fd;                     /* File descriptor for temp file */
  45   int           tries;                  /* Number of tries */
  46   const char    *tmpdir;                /* TMPDIR environment var */
  47 #ifdef WIN32
  48   char          tmppath[1024];          /* Windows temporary directory */
  49   DWORD         curtime;                /* Current time */
  50 #else
  51   struct timeval curtime;               /* Current time */
  52 #endif /* WIN32 */
  53
  54
  55  /*
  56   * See if TMPDIR is defined...
  57   */
  58
  59 #ifdef WIN32
  60   if ((tmpdir = getenv("TEMP")) == NULL)
  61   {
  62     GetTempPath(sizeof(tmppath), tmppath);
  63     tmpdir = tmppath;
  64   }
  65 #else
  66  /*
  67   * Previously we put root temporary files in the default CUPS temporary
  68   * directory under /var/spool/cups.  However, since the scheduler cleans
  69   * out temporary files there and runs independently of the user apps, we
  70   * don't want to use it unless specifically told to by cupsd.
  71   */
  72
  73   if ((tmpdir = getenv("TMPDIR")) == NULL)
  74 #  if defined(__APPLE__) && !TARGET_OS_IOS
  75     tmpdir = "/private/tmp";            /* /tmp is a symlink to /private/tmp */
  76 #  else
  77     tmpdir = "/tmp";
  78 #  endif /* __APPLE__  && !TARGET_OS_IOS */
  79 #endif /* WIN32 */
  80
  81  /*
  82   * Make the temporary name using the specified directory...
  83   */
  84
  85   tries = 0;
  86
  87   do
  88   {
  89 #ifdef WIN32
  90    /*
  91     * Get the current time of day...
  92     */
  93
  94     curtime =  GetTickCount() + tries;
  95
  96    /*
  97     * Format a string using the hex time values...
  98     */
  99
 100     snprintf(filename, (size_t)len - 1, "%s/%05lx%08lx", tmpdir, GetCurrentProcessId(), curtime);
 101 #else
 102    /*
 103     * Get the current time of day...
 104     */
 105
 106     gettimeofday(&curtime, NULL);
 107
 108    /*
 109     * Format a string using the hex time values...
 110     */
 111
 112     snprintf(filename, (size_t)len - 1, "%s/%05x%08x", tmpdir, (unsigned)getpid(), (unsigned)(curtime.tv_sec + curtime.tv_usec + tries));
 113 #endif /* WIN32 */
 114
 115    /*
 116     * Open the file in "exclusive" mode, making sure that we don't
 117     * stomp on an existing file or someone's symlink crack...
 118     */
 119
 120 #ifdef WIN32
 121     fd = open(filename, _O_CREAT | _O_RDWR | _O_TRUNC | _O_BINARY,
 122               _S_IREAD | _S_IWRITE);
 123 #elif defined(O_NOFOLLOW)
 124     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 125 #else
 126     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 127 #endif /* WIN32 */
 128
 129     if (fd < 0 && errno != EEXIST)
 130       break;
 131
 132     tries ++;
 133   }
 134   while (fd < 0 && tries < 1000);
 135
 136  /*
 137   * Return the file descriptor...
 138   */
 139
 140   return (fd);
 141 }
 142
 143
 144 /*
 145  * 'cupsTempFile()' - Generates a temporary filename.
 146  *
 147  * The temporary filename is returned in the filename buffer.
 148  * This function is deprecated and will no longer generate a temporary
 149  * filename - use @link cupsTempFd@ or @link cupsTempFile2@ instead.
 150  *
 151  * @deprecated@
 152  */
 153
 154 char *                                  /* O - Filename or @code NULL@ on error */
 155 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 156              int  len)                  /* I - Size of buffer */
 157 {
 158   (void)len;
 159
 160   if (filename)
 161     *filename = '\0';
 162
 163   return (NULL);
 164 }
 165
 166
 167 /*
 168  * 'cupsTempFile2()' - Creates a temporary CUPS file.
 169  *
 170  * The temporary filename is returned in the filename buffer.
 171  * The temporary file is opened for writing.
 172  *
 173  * @since CUPS 1.2/OS X 10.5@
 174  */
 175
 176 cups_file_t *                           /* O - CUPS file or @code NULL@ on error */
 177 cupsTempFile2(char *filename,           /* I - Pointer to buffer */
 178               int  len)                 /* I - Size of buffer */
 179 {
 180   cups_file_t   *file;                  /* CUPS file */
 181   int           fd;                     /* File descriptor */
 182
 183
 184   if ((fd = cupsTempFd(filename, len)) < 0)
 185     return (NULL);
 186   else if ((file = cupsFileOpenFd(fd, "w")) == NULL)
 187   {
 188     close(fd);
 189     unlink(filename);
 190     return (NULL);
 191   }
 192   else
 193     return (file);
 194 }
 195
 196
 197 /*
 198  * End of "$Id$".
 199  */