diff options
Diffstat (limited to 'sysdeps/posix/mkstemp.c')
-rw-r--r-- | sysdeps/posix/mkstemp.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/sysdeps/posix/mkstemp.c b/sysdeps/posix/mkstemp.c new file mode 100644 index 0000000..9f4f68d --- /dev/null +++ b/sysdeps/posix/mkstemp.c @@ -0,0 +1,64 @@ +/* Copyright (C) 1991, 1992 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., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <string.h> +#include <errno.h> +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> + +/* 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 +DEFUN(mkstemp, (template), char *template) +{ + static CONST char letters[] + = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; + size_t len; + size_t i; + + len = strlen (template); + if (len < 6 || strcmp (&template[len - 6], "XXXXXX")) + { + errno = EINVAL; + return -1; + } + + if (sprintf (&template[len - 5], "%.5u", + (unsigned int) getpid () % 100000) != 5) + /* Inconceivable lossage. */ + return -1; + + for (i = 0; i < sizeof (letters); ++i) + { + int fd; + + template[len - 6] = letters[i]; + + fd = open (template, O_RDWR|O_CREAT|O_EXCL, 0666); + if (fd >= 0) + return fd; + } + + /* We return the null string if we can't find a unique file name. */ + template[0] = '\0'; + return -1; +} |