cups/tempfile.c

   1 /*
   2  * "$Id: tempfile.c 6599 2007-06-22 18:11:12Z mike $"
   3  *
   4  *   Temp file utilities for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 1997-2006 by Easy Software Products.
   7  *
   8  *   These coded instructions, statements, and computer programs are the
   9  *   property of Easy Software Products and are protected by Federal
  10  *   copyright law.  Distribution and use rights are outlined in the file
  11  *   "LICENSE.txt" which should have been included with this file.  If this
  12  *   file is missing or damaged please contact Easy Software Products
  13  *   at:
  14  *
  15  *       Attn: CUPS Licensing Information
  16  *       Easy Software Products
  17  *       44141 Airport View Drive, Suite 204
  18  *       Hollywood, Maryland 20636 USA
  19  *
  20  *       Voice: (301) 373-9600
  21  *       EMail: cups-info@cups.org
  22  *         WWW: http://www.cups.org
  23  *
  24  *   This file is subject to the Apple OS-Developed Software exception.
  25  *
  26  * Contents:
  27  *
  28  *   cupsTempFd()    - Creates a temporary file.
  29  *   cupsTempFile()  - Generates a temporary filename.
  30  *   cupsTempFile2() - Creates a temporary CUPS file.
  31  */
  32
  33 /*
  34  * Include necessary headers...
  35  */
  36
  37 #include "globals.h"
  38 #include "debug.h"
  39 #include <stdlib.h>
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <sys/stat.h>
  43 #if defined(WIN32) || defined(__EMX__)
  44 #  include <io.h>
  45 #else
  46 #  include <unistd.h>
  47 #endif /* WIN32 || __EMX__ */
  48
  49
  50 /*
  51  * 'cupsTempFd()' - Creates a temporary file.
  52  *
  53  * The temporary filename is returned in the filename buffer.
  54  * The temporary file is opened for reading and writing.
  55  */
  56
  57 int                                     /* O - New file descriptor or -1 on error */
  58 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  59            int  len)                    /* I - Size of buffer */
  60 {
  61   int           fd;                     /* File descriptor for temp file */
  62   int           tries;                  /* Number of tries */
  63   const char    *tmpdir;                /* TMPDIR environment var */
  64 #ifdef WIN32
  65   char          tmppath[1024];          /* Windows temporary directory */
  66   DWORD         curtime;                /* Current time */
  67 #else
  68   struct timeval curtime;               /* Current time */
  69 #endif /* WIN32 */
  70
  71
  72  /*
  73   * See if TMPDIR is defined...
  74   */
  75
  76 #ifdef WIN32
  77   if ((tmpdir = getenv("TEMP")) == NULL)
  78   {
  79     GetTempPath(sizeof(tmppath), tmppath);
  80     tmpdir = tmppath;
  81   }
  82 #else
  83  /*
  84   * Previously we put root temporary files in the default CUPS temporary
  85   * directory under /var/spool/cups.  However, since the scheduler cleans
  86   * out temporary files there and runs independently of the user apps, we
  87   * don't want to use it unless specifically told to by cupsd.
  88   */
  89
  90   if ((tmpdir = getenv("TMPDIR")) == NULL)
  91 #  ifdef __APPLE__
  92     tmpdir = "/private/tmp";            /* /tmp is a symlink to /private/tmp */
  93 #  else
  94     tmpdir = "/tmp";
  95 #  endif /* __APPLE__ */
  96 #endif /* WIN32 */
  97
  98  /*
  99   * Make the temporary name using the specified directory...
 100   */
 101
 102   tries = 0;
 103
 104   do
 105   {
 106 #ifdef WIN32
 107    /*
 108     * Get the current time of day...
 109     */
 110
 111     curtime =  GetTickCount() + tries;
 112
 113    /*
 114     * Format a string using the hex time values...
 115     */
 116
 117     snprintf(filename, len - 1, "%s/%05lx%08lx", tmpdir,
 118              GetCurrentProcessId(), curtime);
 119 #else
 120    /*
 121     * Get the current time of day...
 122     */
 123
 124     gettimeofday(&curtime, NULL);
 125
 126    /*
 127     * Format a string using the hex time values...
 128     */
 129
 130     snprintf(filename, len - 1, "%s/%08lx%05lx", tmpdir,
 131              (unsigned long)curtime.tv_sec, (unsigned long)curtime.tv_usec);
 132 #endif /* WIN32 */
 133
 134    /*
 135     * Open the file in "exclusive" mode, making sure that we don't
 136     * stomp on an existing file or someone's symlink crack...
 137     */
 138
 139 #ifdef WIN32
 140     fd = open(filename, _O_CREAT | _O_RDWR | _O_TRUNC | _O_BINARY,
 141               _S_IREAD | _S_IWRITE);
 142 #elif defined(O_NOFOLLOW)
 143     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 144 #else
 145     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 146 #endif /* WIN32 */
 147
 148     if (fd < 0 && errno != EEXIST)
 149       break;
 150
 151     tries ++;
 152   }
 153   while (fd < 0 && tries < 1000);
 154
 155  /*
 156   * Return the file descriptor...
 157   */
 158
 159   return (fd);
 160 }
 161
 162
 163 /*
 164  * 'cupsTempFile()' - Generates a temporary filename.
 165  *
 166  * The temporary filename is returned in the filename buffer.
 167  * This function is deprecated - use cupsTempFd() or cupsTempFile2()
 168  * instead.
 169  *
 170  * @deprecated@
 171  */
 172
 173 char *                                  /* O - Filename or NULL on error */
 174 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 175              int  len)                  /* I - Size of buffer */
 176 {
 177   int           fd;                     /* File descriptor for temp file */
 178   _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */
 179
 180
 181  /*
 182   * See if a filename was specified...
 183   */
 184
 185   if (filename == NULL)
 186   {
 187     filename = cg->tempfile;
 188     len      = sizeof(cg->tempfile);
 189   }
 190
 191  /*
 192   * Create the temporary file...
 193   */
 194
 195   if ((fd = cupsTempFd(filename, len)) < 0)
 196     return (NULL);
 197
 198  /*
 199   * Close the temp file - it'll be reopened later as needed...
 200   */
 201
 202   close(fd);
 203
 204  /*
 205   * Return the temp filename...
 206   */
 207
 208   return (filename);
 209 }
 210
 211
 212 /*
 213  * 'cupsTempFile2()' - Creates a temporary CUPS file.
 214  *
 215  * The temporary filename is returned in the filename buffer.
 216  * The temporary file is opened for writing.
 217  *
 218  * @since CUPS 1.2@
 219  */
 220
 221 cups_file_t *                           /* O - CUPS file or NULL on error */
 222 cupsTempFile2(char *filename,           /* I - Pointer to buffer */
 223               int  len)                 /* I - Size of buffer */
 224 {
 225   cups_file_t   *file;                  /* CUPS file */
 226   int           fd;                     /* File descriptor */
 227
 228
 229   if ((fd = cupsTempFd(filename, len)) < 0)
 230     return (NULL);
 231   else if ((file = cupsFileOpenFd(fd, "w")) == NULL)
 232   {
 233     close(fd);
 234     unlink(filename);
 235     return (NULL);
 236   }
 237   else
 238     return (file);
 239 }
 240
 241
 242 /*
 243  * End of "$Id: tempfile.c 6599 2007-06-22 18:11:12Z mike $".
 244  */