cups/tempfile.c

   1 /*
   2  * "$Id: tempfile.c 10996 2013-05-29 11:51:34Z msweet $"
   3  *
   4  *   Temp file utilities for CUPS.
   5  *
   6  *   Copyright 2007-2012 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 "cups-private.h"
  29 #include <stdlib.h>
  30 #include <fcntl.h>
  31 #include <sys/stat.h>
  32 #if defined(WIN32) || defined(__EMX__)
  33 #  include <io.h>
  34 #else
  35 #  include <unistd.h>
  36 #endif /* WIN32 || __EMX__ */
  37
  38
  39 /*
  40  * 'cupsTempFd()' - Creates a temporary file.
  41  *
  42  * The temporary filename is returned in the filename buffer.
  43  * The temporary file is opened for reading and writing.
  44  */
  45
  46 int                                     /* O - New file descriptor or -1 on error */
  47 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  48            int  len)                    /* I - Size of buffer */
  49 {
  50   int           fd;                     /* File descriptor for temp file */
  51   int           tries;                  /* Number of tries */
  52   const char    *tmpdir;                /* TMPDIR environment var */
  53 #ifdef WIN32
  54   char          tmppath[1024];          /* Windows temporary directory */
  55   DWORD         curtime;                /* Current time */
  56 #else
  57   struct timeval curtime;               /* Current time */
  58 #endif /* WIN32 */
  59
  60
  61  /*
  62   * See if TMPDIR is defined...
  63   */
  64
  65 #ifdef WIN32
  66   if ((tmpdir = getenv("TEMP")) == NULL)
  67   {
  68     GetTempPath(sizeof(tmppath), tmppath);
  69     tmpdir = tmppath;
  70   }
  71 #else
  72  /*
  73   * Previously we put root temporary files in the default CUPS temporary
  74   * directory under /var/spool/cups.  However, since the scheduler cleans
  75   * out temporary files there and runs independently of the user apps, we
  76   * don't want to use it unless specifically told to by cupsd.
  77   */
  78
  79   if ((tmpdir = getenv("TMPDIR")) == NULL)
  80 #  ifdef __APPLE__
  81     tmpdir = "/private/tmp";            /* /tmp is a symlink to /private/tmp */
  82 #  else
  83     tmpdir = "/tmp";
  84 #  endif /* __APPLE__ */
  85 #endif /* WIN32 */
  86
  87  /*
  88   * Make the temporary name using the specified directory...
  89   */
  90
  91   tries = 0;
  92
  93   do
  94   {
  95 #ifdef WIN32
  96    /*
  97     * Get the current time of day...
  98     */
  99
 100     curtime =  GetTickCount() + tries;
 101
 102    /*
 103     * Format a string using the hex time values...
 104     */
 105
 106     snprintf(filename, len - 1, "%s/%05lx%08lx", tmpdir,
 107              GetCurrentProcessId(), curtime);
 108 #else
 109    /*
 110     * Get the current time of day...
 111     */
 112
 113     gettimeofday(&curtime, NULL);
 114
 115    /*
 116     * Format a string using the hex time values...
 117     */
 118
 119     snprintf(filename, len - 1, "%s/%05x%08x", tmpdir, (unsigned)getpid(),
 120              (unsigned)(curtime.tv_sec + curtime.tv_usec + tries));
 121 #endif /* WIN32 */
 122
 123    /*
 124     * Open the file in "exclusive" mode, making sure that we don't
 125     * stomp on an existing file or someone's symlink crack...
 126     */
 127
 128 #ifdef WIN32
 129     fd = open(filename, _O_CREAT | _O_RDWR | _O_TRUNC | _O_BINARY,
 130               _S_IREAD | _S_IWRITE);
 131 #elif defined(O_NOFOLLOW)
 132     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 133 #else
 134     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 135 #endif /* WIN32 */
 136
 137     if (fd < 0 && errno != EEXIST)
 138       break;
 139
 140     tries ++;
 141   }
 142   while (fd < 0 && tries < 1000);
 143
 144  /*
 145   * Return the file descriptor...
 146   */
 147
 148   return (fd);
 149 }
 150
 151
 152 /*
 153  * 'cupsTempFile()' - Generates a temporary filename.
 154  *
 155  * The temporary filename is returned in the filename buffer.
 156  * This function is deprecated - use @link cupsTempFd@ or
 157  * @link cupsTempFile2@ instead.
 158  *
 159  * @deprecated@
 160  */
 161
 162 char *                                  /* O - Filename or @code NULL@ on error */
 163 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 164              int  len)                  /* I - Size of buffer */
 165 {
 166   int           fd;                     /* File descriptor for temp file */
 167   _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */
 168
 169
 170  /*
 171   * See if a filename was specified...
 172   */
 173
 174   if (filename == NULL)
 175   {
 176     filename = cg->tempfile;
 177     len      = sizeof(cg->tempfile);
 178   }
 179
 180  /*
 181   * Create the temporary file...
 182   */
 183
 184   if ((fd = cupsTempFd(filename, len)) < 0)
 185     return (NULL);
 186
 187  /*
 188   * Close the temp file - it'll be reopened later as needed...
 189   */
 190
 191   close(fd);
 192
 193  /*
 194   * Return the temp filename...
 195   */
 196
 197   return (filename);
 198 }
 199
 200
 201 /*
 202  * 'cupsTempFile2()' - Creates a temporary CUPS file.
 203  *
 204  * The temporary filename is returned in the filename buffer.
 205  * The temporary file is opened for writing.
 206  *
 207  * @since CUPS 1.2/OS X 10.5@
 208  */
 209
 210 cups_file_t *                           /* O - CUPS file or @code NULL@ on error */
 211 cupsTempFile2(char *filename,           /* I - Pointer to buffer */
 212               int  len)                 /* I - Size of buffer */
 213 {
 214   cups_file_t   *file;                  /* CUPS file */
 215   int           fd;                     /* File descriptor */
 216
 217
 218   if ((fd = cupsTempFd(filename, len)) < 0)
 219     return (NULL);
 220   else if ((file = cupsFileOpenFd(fd, "w")) == NULL)
 221   {
 222     close(fd);
 223     unlink(filename);
 224     return (NULL);
 225   }
 226   else
 227     return (file);
 228 }
 229
 230
 231 /*
 232  * End of "$Id: tempfile.c 10996 2013-05-29 11:51:34Z msweet $".
 233  */