src/libs/libgroff/tmpfile.cc

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
   3      Written by James Clark (jjc@jclark.com)
   4
   5 This file is part of groff.
   6
   7 groff is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with groff; see the file COPYING.  If not, write to the Free Software
  19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  20
  21 #include <stdio.h>
  22 #include <errno.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25
  26 #include "posix.h"
  27 #include "lib.h"
  28 #include "errarg.h"
  29 #include "error.h"
  30
  31 extern "C" {
  32   // Sun's stdlib.h fails to declare this.
  33   char *mktemp(char *);
  34   int mkstemp(char *);
  35 }
  36
  37 // If this is set, create temporary files there
  38 #define GROFF_TMPDIR_ENVVAR "GROFF_TMPDIR"
  39 // otherwise if this is set, create temporary files there
  40 #define TMPDIR_ENVVAR "TMPDIR"
  41 // otherwise create temporary files here.
  42 #define DEFAULT_TMPDIR "/tmp"
  43 // Use this as the prefix for temporary filenames.
  44 #define TMPFILE_PREFIX  "groff"
  45
  46 /*
  47  *  Generate a temporary name template with a postfix
  48  *  immediately after the TMPFILE_PREFIX.
  49  *  It uses the groff preferences for a temporary directory.
  50  *  Note that no file name is either created or opened,
  51  *  only the *template* is returned.
  52  */
  53
  54 char *xtmptemplate(char *postfix=0)
  55 {
  56   const char *dir = getenv(GROFF_TMPDIR_ENVVAR);
  57   int postlen = 0;
  58
  59   if (postfix)
  60     postlen = strlen(postfix);
  61
  62   if (!dir) {
  63     dir = getenv(TMPDIR_ENVVAR);
  64     if (!dir)
  65       dir = DEFAULT_TMPDIR;
  66   }
  67
  68   const char *p = strrchr(dir, '/');
  69   int needs_slash = (!p || p[1]);
  70   char *templ = new char[strlen(dir) + needs_slash
  71                 + sizeof(TMPFILE_PREFIX) - 1 + 6 + 1 + postlen];
  72   strcpy(templ, dir);
  73   if (needs_slash)
  74     strcat(templ, "/");
  75   strcat(templ, TMPFILE_PREFIX);
  76   if (postlen > 0)
  77     strcat(templ, postfix);
  78   strcat(templ, "XXXXXX");
  79
  80   return( templ );
  81 }
  82
  83 // Open a temporary file and with fatal error on failure.
  84
  85 FILE *xtmpfile(char **namep=0, char *postfix=0, int do_unlink=1)
  86 {
  87   char *templ = xtmptemplate(postfix);
  88
  89 #ifdef HAVE_MKSTEMP
  90   errno = 0;
  91   int fd = mkstemp(templ);
  92   if (fd < 0)
  93     fatal("cannot create temporary file: %1", strerror(errno));
  94   errno = 0;
  95   FILE *fp = fdopen(fd, "w+");
  96   if (!fp)
  97     fatal("fdopen: %1", strerror(errno));
  98 #else /* not HAVE_MKSTEMP */
  99   if (!mktemp(templ) || !templ[0])
 100     fatal("cannot create file name for temporary file");
 101   errno = 0;
 102   FILE *fp = fopen(templ, "w+");
 103   if (!fp)
 104     fatal("cannot open `%1': %2", templ, strerror(errno));
 105 #endif /* not HAVE_MKSTEMP */
 106   if ((do_unlink) && (unlink(templ) < 0))
 107     error("cannot unlink `%1': %2", templ, strerror(errno));
 108   if ((namep != 0) && ((*namep) != 0)) {
 109     *namep = templ;
 110   } else {
 111     a_delete templ;
 112   }
 113   return fp;
 114 }
 115
 116 #if 0
 117 // If you're not running Unix, the following will do:
 118 FILE *xtmpfile(char **namep, char *postfix=0, int do_unlink=1)
 119 {
 120   FILE *fp = tmpfile();
 121   if (!fp)
 122     fatal("couldn't create temporary file");
 123   return fp;
 124 }
 125 #endif