cups/tempfile.c

   1 /*
   2  * "$Id: tempfile.c 6649 2007-07-11 21:46:42Z mike $"
   3  *
   4  *   Temp file utilities for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 2007-2008 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  * Contents:
  18  *
  19  *   cupsTempFd()    - Creates a temporary file.
  20  *   cupsTempFile()  - Generates a temporary filename.
  21  *   cupsTempFile2() - Creates a temporary CUPS file.
  22  */
  23
  24 /*
  25  * Include necessary headers...
  26  */
  27
  28 #include "globals.h"
  29 #include "debug.h"
  30 #include <stdlib.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <sys/stat.h>
  34 #if defined(WIN32) || defined(__EMX__)
  35 #  include <io.h>
  36 #else
  37 #  include <unistd.h>
  38 #endif /* WIN32 || __EMX__ */
  39
  40
  41 /*
  42  * 'cupsTempFd()' - Creates a temporary file.
  43  *
  44  * The temporary filename is returned in the filename buffer.
  45  * The temporary file is opened for reading and writing.
  46  */
  47
  48 int                                     /* O - New file descriptor or -1 on error */
  49 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  50            int  len)                    /* I - Size of buffer */
  51 {
  52   int           fd;                     /* File descriptor for temp file */
  53   int           tries;                  /* Number of tries */
  54   const char    *tmpdir;                /* TMPDIR environment var */
  55 #ifdef WIN32
  56   char          tmppath[1024];          /* Windows temporary directory */
  57   DWORD         curtime;                /* Current time */
  58 #else
  59   struct timeval curtime;               /* Current time */
  60 #endif /* WIN32 */
  61
  62
  63  /*
  64   * See if TMPDIR is defined...
  65   */
  66
  67 #ifdef WIN32
  68   if ((tmpdir = getenv("TEMP")) == NULL)
  69   {
  70     GetTempPath(sizeof(tmppath), tmppath);
  71     tmpdir = tmppath;
  72   }
  73 #else
  74  /*
  75   * Previously we put root temporary files in the default CUPS temporary
  76   * directory under /var/spool/cups.  However, since the scheduler cleans
  77   * out temporary files there and runs independently of the user apps, we
  78   * don't want to use it unless specifically told to by cupsd.
  79   */
  80
  81   if ((tmpdir = getenv("TMPDIR")) == NULL)
  82 #  ifdef __APPLE__
  83     tmpdir = "/private/tmp";            /* /tmp is a symlink to /private/tmp */
  84 #  else
  85     tmpdir = "/tmp";
  86 #  endif /* __APPLE__ */
  87 #endif /* WIN32 */
  88
  89  /*
  90   * Make the temporary name using the specified directory...
  91   */
  92
  93   tries = 0;
  94
  95   do
  96   {
  97 #ifdef WIN32
  98    /*
  99     * Get the current time of day...
 100     */
 101
 102     curtime =  GetTickCount() + tries;
 103
 104    /*
 105     * Format a string using the hex time values...
 106     */
 107
 108     snprintf(filename, len - 1, "%s/%05lx%08lx", tmpdir,
 109              GetCurrentProcessId(), curtime);
 110 #else
 111    /*
 112     * Get the current time of day...
 113     */
 114
 115     gettimeofday(&curtime, NULL);
 116
 117    /*
 118     * Format a string using the hex time values...
 119     */
 120
 121     snprintf(filename, len - 1, "%s/%08lx%05lx", tmpdir,
 122              (unsigned long)curtime.tv_sec, (unsigned long)curtime.tv_usec);
 123 #endif /* WIN32 */
 124
 125    /*
 126     * Open the file in "exclusive" mode, making sure that we don't
 127     * stomp on an existing file or someone's symlink crack...
 128     */
 129
 130 #ifdef WIN32
 131     fd = open(filename, _O_CREAT | _O_RDWR | _O_TRUNC | _O_BINARY,
 132               _S_IREAD | _S_IWRITE);
 133 #elif defined(O_NOFOLLOW)
 134     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 135 #else
 136     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 137 #endif /* WIN32 */
 138
 139     if (fd < 0 && errno != EEXIST)
 140       break;
 141
 142     tries ++;
 143   }
 144   while (fd < 0 && tries < 1000);
 145
 146  /*
 147   * Return the file descriptor...
 148   */
 149
 150   return (fd);
 151 }
 152
 153
 154 /*
 155  * 'cupsTempFile()' - Generates a temporary filename.
 156  *
 157  * The temporary filename is returned in the filename buffer.
 158  * This function is deprecated - use @link cupsTempFd@ or
 159  * @link cupsTempFile2@ instead.
 160  *
 161  * @deprecated@
 162  */
 163
 164 char *                                  /* O - Filename or @code NULL@ on error */
 165 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 166              int  len)                  /* I - Size of buffer */
 167 {
 168   int           fd;                     /* File descriptor for temp file */
 169   _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */
 170
 171
 172  /*
 173   * See if a filename was specified...
 174   */
 175
 176   if (filename == NULL)
 177   {
 178     filename = cg->tempfile;
 179     len      = sizeof(cg->tempfile);
 180   }
 181
 182  /*
 183   * Create the temporary file...
 184   */
 185
 186   if ((fd = cupsTempFd(filename, len)) < 0)
 187     return (NULL);
 188
 189  /*
 190   * Close the temp file - it'll be reopened later as needed...
 191   */
 192
 193   close(fd);
 194
 195  /*
 196   * Return the temp filename...
 197   */
 198
 199   return (filename);
 200 }
 201
 202
 203 /*
 204  * 'cupsTempFile2()' - Creates a temporary CUPS file.
 205  *
 206  * The temporary filename is returned in the filename buffer.
 207  * The temporary file is opened for writing.
 208  *
 209  * @since CUPS 1.2@
 210  */
 211
 212 cups_file_t *                           /* O - CUPS file or @code NULL@ on error */
 213 cupsTempFile2(char *filename,           /* I - Pointer to buffer */
 214               int  len)                 /* I - Size of buffer */
 215 {
 216   cups_file_t   *file;                  /* CUPS file */
 217   int           fd;                     /* File descriptor */
 218
 219
 220   if ((fd = cupsTempFd(filename, len)) < 0)
 221     return (NULL);
 222   else if ((file = cupsFileOpenFd(fd, "w")) == NULL)
 223   {
 224     close(fd);
 225     unlink(filename);
 226     return (NULL);
 227   }
 228   else
 229     return (file);
 230 }
 231
 232
 233 /*
 234  * End of "$Id: tempfile.c 6649 2007-07-11 21:46:42Z mike $".
 235  */