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-rw-r--r--src/sys/stdlib/mkstemp.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/src/sys/stdlib/mkstemp.c b/src/sys/stdlib/mkstemp.c
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+/* Copyright (C) 1991, 1992, 1996, 1998 Free Software Foundation, Inc.
+ This file is part of 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 <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+#include <stdint.h>
+typedef uint64_t big_type;
+
+/* this ifdef crap lifted from slurp
+This is a hack!! We need binary mode files, but the 'b' flag to fdopen is
+evidently useless, so I'm doing it at this level instead. Dumb. */
+#ifndef O_BINARY
+# ifdef O_RAW
+# define O_BINARY O_RAW
+# else
+# define O_BINARY 0
+# endif
+#endif
+
+int mkstemp(char *template);
+
+/* Generate a unique temporary file name from TEMPLATE.
+ 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(char *template)
+{
+ static const char letters[]
+ = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+ static big_type value;
+ struct timeval tv;
+ char *XXXXXX;
+ size_t len;
+ int count;
+
+ len = strlen (template);
+ if (len < 6 || strcmp (&template[len - 6], "XXXXXX"))
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* This is where the Xs start. */
+ XXXXXX = &template[len - 6];
+
+ /* Get some more or less random data. */
+ gettimeofday (&tv, NULL);
+ value += ((big_type) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
+
+ for (count = 0; count < TMP_MAX; ++count)
+ {
+ big_type 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|O_BINARY, 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;
+}
+
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