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Diffstat (limited to 'src/mkdtemp.c')
| -rw-r--r-- | src/mkdtemp.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/src/mkdtemp.c b/src/mkdtemp.c new file mode 100644 index 0000000..1508102 --- /dev/null +++ b/src/mkdtemp.c @@ -0,0 +1,201 @@ +/* Copyright (C) 1999, 2001-2002 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. */ + +/* Extracted from misc/mkdtemp.c and sysdeps/posix/tempname.c. */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +/* Specification. */ +#include "mkdtemp.h" + +#include <errno.h> +#ifndef __set_errno +# define __set_errno(Val) errno = (Val) +#endif + +#include <stddef.h> +#include <stdlib.h> +#include <string.h> + +#include <stdio.h> +#ifndef TMP_MAX +# define TMP_MAX 238328 +#endif + +#if HAVE_STDINT_H_WITH_UINTMAX || _LIBC +# include <stdint.h> +#endif + +#if HAVE_INTTYPES_H_WITH_UINTMAX || _LIBC +# include <inttypes.h> +#endif + +#if HAVE_UNISTD_H || _LIBC +# include <unistd.h> +#endif + +#if HAVE_GETTIMEOFDAY || _LIBC +# if HAVE_SYS_TIME_H || _LIBC +# include <sys/time.h> +# endif +#else +# if HAVE_TIME_H || _LIBC +# include <time.h> +# endif +#endif + +#include <sys/stat.h> +#if STAT_MACROS_BROKEN +# undef S_ISDIR +#endif +#if !defined S_ISDIR && defined S_IFDIR +# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR) +#endif +#if !S_IRUSR && S_IREAD +# define S_IRUSR S_IREAD +#endif +#if !S_IRUSR +# define S_IRUSR 00400 +#endif +#if !S_IWUSR && S_IWRITE +# define S_IWUSR S_IWRITE +#endif +#if !S_IWUSR +# define S_IWUSR 00200 +#endif +#if !S_IXUSR && S_IEXEC +# define S_IXUSR S_IEXEC +#endif +#if !S_IXUSR +# define S_IXUSR 00100 +#endif + +#if !_LIBC +# define __getpid getpid +# define __gettimeofday gettimeofday +# define __mkdir mkdir +#endif + +/* Use the widest available unsigned type if uint64_t is not + available. The algorithm below extracts a number less than 62**6 + (approximately 2**35.725) from uint64_t, so ancient hosts where + uintmax_t is only 32 bits lose about 3.725 bits of randomness, + which is better than not having mkstemp at all. */ +#if !defined UINT64_MAX && !defined uint64_t +# define uint64_t uintmax_t +#endif + +/* These are the characters used in temporary filenames. */ +static const char letters[] = +"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; + +/* Generate a temporary file name based on TMPL. TMPL must match the + rules for mk[s]temp (i.e. end in "XXXXXX"). The name constructed + does not exist at the time of the call to __gen_tempname. TMPL is + overwritten with the result. + + KIND is: + __GT_DIR: create a directory, which will be mode 0700. + + We use a clever algorithm to get hard-to-predict names. */ +static int +gen_tempname (tmpl) + char *tmpl; +{ + int len; + char *XXXXXX; + static uint64_t value; + uint64_t random_time_bits; + int count, fd = -1; + int save_errno = errno; + + len = strlen (tmpl); + if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX")) + { + __set_errno (EINVAL); + return -1; + } + + /* This is where the Xs start. */ + XXXXXX = &tmpl[len - 6]; + + /* Get some more or less random data. */ +#ifdef RANDOM_BITS + RANDOM_BITS (random_time_bits); +#else +# if HAVE_GETTIMEOFDAY || _LIBC + { + struct timeval tv; + __gettimeofday (&tv, NULL); + random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; + } +# else + random_time_bits = time (NULL); +# endif +#endif + value += random_time_bits ^ __getpid (); + + for (count = 0; count < TMP_MAX; value += 7777, ++count) + { + uint64_t v = value; + + /* 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 = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR); + + if (fd >= 0) + { + __set_errno (save_errno); + return fd; + } + else if (errno != EEXIST) + return -1; + } + + /* We got out of the loop because we ran out of combinations to try. */ + __set_errno (EEXIST); + return -1; +} + +/* Generate a unique temporary directory from TEMPLATE. + The last six characters of TEMPLATE must be "XXXXXX"; + they are replaced with a string that makes the filename unique. + The directory is created, mode 700, and its name is returned. + (This function comes from OpenBSD.) */ +char * +mkdtemp (template) + char *template; +{ + if (gen_tempname (template)) + return NULL; + else + return template; +} |