cups/tempfile.c

   1 /*
   2  * "$Id$"
   3  *
   4  *   Temp file utilities for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 1997-2001 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 20636-3111 USA
  19  *
  20  *       Voice: (301) 373-9603
  21  *       EMail: cups-info@cups.org
  22  *         WWW: http://www.cups.org
  23  *
  24  * Contents:
  25  *
  26  *   cupsTempFd()   - Create a temporary file.
  27  *   cupsTempFile() - Generate a temporary filename.
  28  */
  29
  30 /*
  31  * Include necessary headers...
  32  */
  33
  34 #include "cups.h"
  35 #include "string.h"
  36 #include "debug.h"
  37 #include <stdlib.h>
  38 #include <ctype.h>
  39 #include <errno.h>
  40 #include <fcntl.h>
  41 #include <sys/stat.h>
  42 #if defined(WIN32) || defined(__EMX__)
  43 #  include <io.h>
  44 #else
  45 #  include <unistd.h>
  46 #endif /* WIN32 || __EMX__ */
  47
  48
  49 /*
  50  * 'cupsTempFd()' - Create a temporary file.
  51  */
  52
  53 int                                     /* O - New file descriptor */
  54 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  55            int  len)                    /* I - Size of buffer */
  56 {
  57   int           fd;                     /* File descriptor for temp file */
  58 #ifdef WIN32
  59   char          tmpdir[1024];           /* Windows temporary directory */
  60   DWORD         curtime;                /* Current time */
  61 #else
  62   char          *tmpdir;                /* TMPDIR environment var */
  63   struct timeval curtime;               /* Current time */
  64 #endif /* WIN32 */
  65   static char   buf[1024] = "";         /* Buffer if you pass in NULL and 0 */
  66
  67
  68  /*
  69   * See if a filename was specified...
  70   */
  71
  72   if (filename == NULL)
  73   {
  74     filename = buf;
  75     len      = sizeof(buf);
  76   }
  77
  78  /*
  79   * See if TMPDIR is defined...
  80   */
  81
  82 #ifdef WIN32
  83   GetTempPath(sizeof(tmpdir), tmpdir);
  84 #else
  85   if ((tmpdir = getenv("TMPDIR")) == NULL)
  86   {
  87    /*
  88     * Put root temp files in restricted temp directory...
  89     */
  90
  91     if (getuid() == 0)
  92       tmpdir = CUPS_REQUESTS "/tmp";
  93     else
  94       tmpdir = "/var/tmp";
  95   }
  96 #endif /* WIN32 */
  97
  98  /*
  99   * Make the temporary name using the specified directory...
 100   */
 101
 102   do
 103   {
 104 #ifdef WIN32
 105    /*
 106     * Get the current time of day...
 107     */
 108
 109     curtime = GetTickCount();
 110
 111    /*
 112     * Format a string using the hex time values...
 113     */
 114
 115     snprintf(filename, len - 1, "%s/%08lx", tmpdir, curtime);
 116 #else
 117    /*
 118     * Get the current time of day...
 119     */
 120
 121     gettimeofday(&curtime, NULL);
 122
 123    /*
 124     * Format a string using the hex time values...
 125     */
 126
 127     snprintf(filename, len - 1, "%s/%08lx%05lx", tmpdir,
 128              curtime.tv_sec, curtime.tv_usec);
 129 #endif /* WIN32 */
 130
 131    /*
 132     * Open the file in "exclusive" mode, making sure that we don't
 133     * stomp on an existing file or someone's symlink crack...
 134     */
 135
 136 #ifdef O_NOFOLLOW
 137     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 138 #else
 139     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 140 #endif /* O_NOFOLLOW */
 141
 142     if (fd < 0 && (errno == EPERM || errno == ENOENT))
 143       break; /* Stop immediately if permission denied or the dir doesn't exist! */
 144   }
 145   while (fd < 0);
 146
 147  /*
 148   * Return the file descriptor...
 149   */
 150
 151   return (fd);
 152 }
 153
 154
 155 /*
 156  * 'cupsTempFile()' - Generate a temporary filename.
 157  */
 158
 159 char *                                  /* O - Filename */
 160 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 161              int  len)                  /* I - Size of buffer */
 162 {
 163   int           fd;                     /* File descriptor for temp file */
 164   static char   buf[1024] = "";         /* Buffer if you pass in NULL and 0 */
 165
 166
 167  /*
 168   * See if a filename was specified...
 169   */
 170
 171   if (filename == NULL)
 172   {
 173     filename = buf;
 174     len      = sizeof(buf);
 175   }
 176
 177  /*
 178   * Create the temporary file...
 179   */
 180
 181   if ((fd = cupsTempFd(filename, len)) < 0)
 182     return (NULL);
 183
 184  /*
 185   * Close the temp file - it'll be reopened later as needed...
 186   */
 187
 188   close(fd);
 189
 190  /*
 191   * Return the temp filename...
 192   */
 193
 194   return (filename);
 195 }
 196
 197
 198 /*
 199  * End of "$Id$".
 200  */