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Diffstat (limited to 'newlib/libc/stdio/tmpnam.c')
| -rw-r--r-- | newlib/libc/stdio/tmpnam.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/newlib/libc/stdio/tmpnam.c b/newlib/libc/stdio/tmpnam.c new file mode 100644 index 00000000000..28b394f108b --- /dev/null +++ b/newlib/libc/stdio/tmpnam.c @@ -0,0 +1,208 @@ +/* + * tmpname.c + * Original Author: G. Haley + */ + +/* +FUNCTION +<<tmpnam>>, <<tempnam>>---name for a temporary file + +INDEX + tmpnam +INDEX + tempnam +INDEX + _tmpnam_r +INDEX + _tempnam_r + +ANSI_SYNOPSIS + #include <stdio.h> + char *tmpnam(char *<[s]>); + char *tempnam(char *<[dir]>, char *<[pfx]>); + char *_tmpnam_r(void *<[reent]>, char *<[s]>); + char *_tempnam_r(void *<[reent]>, char *<[dir]>, char *<[pfx]>); + +TRAD_SYNOPSIS + #include <stdio.h> + char *tmpnam(<[s]>) + char *<[s]>; + + char *tempnam(<[dir]>, <[pfx]>) + char *<[dir]>; + char *<[pfx]>; + + char *_tmpnam_r(<[reent]>, <[s]>) + char *<[reent]>; + char *<[s]>; + + char *_tempnam_r(<[reent]>, <[dir]>, <[pfx]>) + char *<[reent]>; + char *<[dir]>; + char *<[pfx]>; + +DESCRIPTION +Use either of these functions to generate a name for a temporary file. +The generated name is guaranteed to avoid collision with other files +(for up to <<TMP_MAX>> calls of either function). + +<<tmpnam>> generates file names with the value of <<P_tmpdir>> +(defined in `<<stdio.h>>') as the leading directory component of the path. + +You can use the <<tmpnam>> argument <[s]> to specify a suitable area +of memory for the generated filename; otherwise, you can call +<<tmpnam(NULL)>> to use an internal static buffer. + +<<tempnam>> allows you more control over the generated filename: you +can use the argument <[dir]> to specify the path to a directory for +temporary files, and you can use the argument <[pfx]> to specify a +prefix for the base filename. + +If <[dir]> is <<NULL>>, <<tempnam>> will attempt to use the value of +environment variable <<TMPDIR>> instead; if there is no such value, +<<tempnam>> uses the value of <<P_tmpdir>> (defined in `<<stdio.h>>'). + +If you don't need any particular prefix to the basename of temporary +files, you can pass <<NULL>> as the <[pfx]> argument to <<tempnam>>. + +<<_tmpnam_r>> and <<_tempnam_r>> are reentrant versions of <<tmpnam>> +and <<tempnam>> respectively. The extra argument <[reent]> is a +pointer to a reentrancy structure. + +WARNINGS +The generated filenames are suitable for temporary files, but do not +in themselves make files temporary. Files with these names must still +be explicitly removed when you no longer want them. + +If you supply your own data area <[s]> for <<tmpnam>>, you must ensure +that it has room for at least <<L_tmpnam>> elements of type <<char>>. + +RETURNS +Both <<tmpnam>> and <<tempnam>> return a pointer to the newly +generated filename. + +PORTABILITY +ANSI C requires <<tmpnam>>, but does not specify the use of +<<P_tmpdir>>. The System V Interface Definition (Issue 2) requires +both <<tmpnam>> and <<tempnam>>. + +Supporting OS subroutines required: <<close>>, <<fstat>>, <<getpid>>, +<<isatty>>, <<lseek>>, <<open>>, <<read>>, <<sbrk>>, <<write>>. + +The global pointer <<environ>> is also required. +*/ + +#include <_ansi.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> +#include <reent.h> +#include <errno.h> + +/* Try to open the file specified, if it can't be opened then try + another one. Return nonzero if successful, otherwise zero. */ + +static int +worker (ptr, result, part1, part2, part3, part4) + struct _reent *ptr; + char *result; + _CONST char *part1; + _CONST char *part2; + int part3; + int *part4; +{ + /* Generate the filename and make sure that there isn't one called + it already. */ + + while (1) + { + int t; + _sprintf_r (ptr, result, "%s/%s%x.%x", part1, part2, part3, *part4); + (*part4)++; + t = _open_r (ptr, result, O_RDONLY, 0); + if (t == -1) + { + if (ptr->_errno == ENOSYS) + { + result[0] = '\0'; + return 0; + } + break; + } + _close_r (ptr, t); + } + return 1; +} + +char * +_DEFUN (_tmpnam_r, (p, s), + struct _reent *p _AND + char *s) +{ + char *result; + int pid; + + if (s == NULL) + { + /* ANSI states we must use an internal static buffer if s is NULL */ + result = p->_emergency; + } + else + { + result = s; + } + pid = _getpid_r (p); + + if (worker (p, result, P_tmpdir, "t", pid, &p->_inc)) + { + p->_inc++; + return result; + } + + return NULL; +} + +char * +_DEFUN (_tempnam_r, (p, dir, pfx), + struct _reent *p _AND + _CONST char *dir _AND + _CONST char *pfx) +{ + char *filename; + int length; + _CONST char *prefix = (pfx) ? pfx : ""; + if (dir == NULL && (dir = getenv ("TMPDIR")) == NULL) + dir = P_tmpdir; + + /* two 8 digit numbers + . / */ + length = strlen (dir) + strlen (prefix) + (4 * sizeof (int)) + 2 + 1; + + filename = _malloc_r (p, length); + if (filename) + { + if (! worker (p, filename, dir, prefix, + _getpid_r (p) ^ (int) (_POINTER_INT) p, &p->_inc)) + return NULL; + } + return filename; +} + +#ifndef _REENT_ONLY + +char * +_DEFUN (tempnam, (dir, pfx), + _CONST char *dir _AND + _CONST char *pfx) +{ + return _tempnam_r (_REENT, dir, pfx); +} + +char * +_DEFUN (tmpnam, (s), + char *s) +{ + return _tmpnam_r (_REENT, s); +} + +#endif |