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authorMarius Vollmer <mvo@zagadka.de>2001-06-02 12:39:09 +0000
committerMarius Vollmer <mvo@zagadka.de>2001-06-02 12:39:09 +0000
commit23cc59681bfcc239de26b9c1e526e5dede63a042 (patch)
tree8cbade05d8469625b93847de3bdc6dc29caae557 /libguile/mkstemp.c
parent26446f99071028b6aa9d87739f46311774f6ebbb (diff)
downloadguile-23cc59681bfcc239de26b9c1e526e5dede63a042.tar.gz
New file, slightly modified from libiberties
mkstemps.c.
Diffstat (limited to 'libguile/mkstemp.c')
-rw-r--r--libguile/mkstemp.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/libguile/mkstemp.c b/libguile/mkstemp.c
new file mode 100644
index 000000000..a35f8d6d0
--- /dev/null
+++ b/libguile/mkstemp.c
@@ -0,0 +1,123 @@
+/* Copyright (C) 1991, 1992, 1996, 1998 Free Software Foundation, Inc.
+ This file is derived from mkstemps.c from the GNU Libiberty Library
+ which in turn is derived from the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include "scmconfig.h"
+
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+/* We need to provide a type for gcc_uint64_t. */
+#ifdef __GNUC__
+typedef unsigned long long gcc_uint64_t;
+#else
+typedef unsigned long gcc_uint64_t;
+#endif
+
+#ifndef TMP_MAX
+#define TMP_MAX 16384
+#endif
+
+/* Generate a unique temporary file name from TEMPLATE.
+
+ TEMPLATE has the form:
+
+ <path>/ccXXXXXX
+
+ The last six characters of TEMPLATE must be "XXXXXX"; they are
+ replaced with a string that makes the filename unique.
+
+ Returns a file descriptor open on the file for reading and writing. */
+int
+mkstemp (template)
+ char *template;
+{
+ static const char letters[]
+ = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+ static gcc_uint64_t value;
+#ifdef HAVE_GETTIMEOFDAY
+ struct timeval tv;
+#endif
+ char *XXXXXX;
+ size_t len;
+ int count;
+
+ len = strlen (template);
+
+ if ((int) len < 6
+ || strncmp (&template[len - 6], "XXXXXX", 6))
+ {
+ return -1;
+ }
+
+ XXXXXX = &template[len - 6];
+
+#ifdef HAVE_GETTIMEOFDAY
+ /* Get some more or less random data. */
+ gettimeofday (&tv, NULL);
+ value += ((gcc_uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
+#else
+ value += getpid ();
+#endif
+
+ for (count = 0; count < TMP_MAX; ++count)
+ {
+ gcc_uint64_t v = value;
+ int fd;
+
+ /* Fill in the random bits. */
+ XXXXXX[0] = letters[v % 62];
+ v /= 62;
+ XXXXXX[1] = letters[v % 62];
+ v /= 62;
+ XXXXXX[2] = letters[v % 62];
+ v /= 62;
+ XXXXXX[3] = letters[v % 62];
+ v /= 62;
+ XXXXXX[4] = letters[v % 62];
+ v /= 62;
+ XXXXXX[5] = letters[v % 62];
+
+ fd = open (template, O_RDWR|O_CREAT|O_EXCL, 0600);
+ if (fd >= 0)
+ /* The file does not exist. */
+ return fd;
+
+ /* This is a random value. It is only necessary that the next
+ TMP_MAX values generated by adding 7777 to VALUE are different
+ with (module 2^32). */
+ value += 7777;
+ }
+
+ /* We return the null string if we can't find a unique file name. */
+ template[0] = '\0';
+ return -1;
+}