mktemp, mkstemp, mkostemp, mkstemps, #include <stdlib.h>
char *mktemp(char *path);
char *mkdtemp(char *path);
int mkstemp(char *path);
int mkstemps(char *path, int suffixlen);
int mkostemp(char *path, int flags);
int mkostemps(char *path, int suffixlen, int flags);
char *_mktemp_r(struct _reent *reent, char *path);
char *_mkdtemp_r(struct _reent *reent, char *path);
int *_mkstemp_r(struct _reent *reent, char *path);
int *_mkstemps_r(struct _reent *reent, char *path, int len);
int *_mkostemp_r(struct _reent *reent, char *path,
int flags);
int *_mkostemps_r(struct _reent *reent, char *path, int len,
int flags);
Description
mktemp, mkstemp, and mkstemps attempt to generate a file name
that is not yet in use for any existing file. mkstemp and mkstemps
create the file and open it for reading and writing; mktemp simply
generates the file name (making mktemp a security risk). mkostemp
and mkostemps allow the addition of other open flags, such
as O_CLOEXEC, O_APPEND, or O_SYNC. On platforms with a
separate text mode, mkstemp forces O_BINARY, while mkostemp
allows the choice between O_BINARY, O_TEXT, or 0 for default.
mkdtemp attempts to create a directory instead of a file, with a
permissions mask of 0700.
You supply a simple pattern for the generated file name, as the string
at path. The pattern should be a valid filename (including path
information if you wish) ending with at least six `X'
characters. The generated filename will match the leading part of the
name you supply, with the trailing `X' characters replaced by some
combination of digits and letters. With mkstemps, the `X'
characters end suffixlen bytes before the end of the string.
The alternate functions _mktemp_r, _mkdtemp_r, _mkstemp_r,
_mkostemp_r, _mkostemps_r, and _mkstemps_r are reentrant
versions. The extra argument reent is a pointer to a reentrancy
structure.
Returns
mktemp returns the pointer path to the modified string
representing an unused filename, unless it could not generate one, or
the pattern you provided is not suitable for a filename; in that case,
it returns NULL. Be aware that there is an inherent race between
generating the name and attempting to create a file by that name;
you are advised to use O_EXCL|O_CREAT.
mkdtemp returns the pointer path to the modified string if the
directory was created, otherwise it returns NULL.
mkstemp, mkstemps, mkostemp, and mkostemps return a file
descriptor to the newly created file, unless it could not generate an
unused filename, or the pattern you provided is not suitable for a
filename; in that case, it returns -1.
Portability
ANSI C does not require either mktemp or mkstemp; the System
V Interface Definition requires mktemp as of Issue 2. POSIX 2001
requires mkstemp, and POSIX 2008 requires mkdtemp while
deprecating mktemp. mkstemps, mkostemp, and mkostemps
are not standardized.
Supporting OS subroutines required: getpid, mkdir, open, stat.