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mktemp(3c) [opensolaris man page]

mktemp(3C)						   Standard C Library Functions 						mktemp(3C)

mktemp - make a unique file name from a template SYNOPSIS
#include <stdlib.h> char *mktemp(char *template); DESCRIPTION
The mktemp() function replaces the contents of the string pointed to by template with a unique file name, and returns template. The string in template should look like a file name with six trailing 'X's; mktemp() will replace the 'X's with a character string that can be used to create a unique file name. Only 26 unique file names per thread can be created for each unique template. RETURN VALUES
The mktemp() function returns the pointer template. If a unique name cannot be created, template points to a null string. ERRORS
No errors are defined. EXAMPLES
Example 1 Generate a filename. The following example replaces the contents of the "template" string with a 10-character filename beginning with the characters "file" and returns a pointer to the "template" string that contains the new filename. #include <stdlib.h> ... char *template = "/tmp/fileXXXXXX"; char *ptr; ptr = mktemp(template); USAGE
Between the time a pathname is created and the file opened, it is possible for some other process to create a file with the same name. The mkstemp(3C) function avoids this problem and is preferred over this function. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |Safe | +-----------------------------+-----------------------------+ SEE ALSO
mkstemp(3C), tmpfile(3C), tmpnam(3C), attributes(5), standards(5) SunOS 5.11 15 Sep 2004 mktemp(3C)

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MKTEMP(3)						     Linux Programmer's Manual							 MKTEMP(3)

mktemp - make a unique temporary filename SYNOPSIS
#include <stdlib.h> char *mktemp(char *template); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): mktemp(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 DESCRIPTION
The mktemp() function generates a unique temporary filename from template. The last six characters of template must be XXXXXX and these are replaced with a string that makes the filename unique. Since it will be modified, template must not be a string constant, but should be declared as a character array. RETURN VALUE
The mktemp() function always returns template. If a unique name was created, the last six bytes of template will have been modified in such a way that the resulting name is unique (i.e., does not exist already) If a unique name could not be created, template is made an empty string. ERRORS
EINVAL The last six characters of template were not XXXXXX. CONFORMING TO
4.3BSD, POSIX.1-2001. POSIX.1-2008 removes the specification of mktemp(). NOTES
The prototype is in <unistd.h> for libc4, libc5, glibc1; glibc2 follows the Single Unix Specification and has the prototype in <stdlib.h>. BUGS
Never use mktemp(). Some implementations follow 4.3BSD and replace XXXXXX by the current process ID and a single letter, so that at most 26 different names can be returned. Since on the one hand the names are easy to guess, and on the other hand there is a race between test- ing whether the name exists and opening the file, every use of mktemp() is a security risk. The race is avoided by mkstemp(3). SEE ALSO
mkstemp(3), tempnam(3), tmpfile(3), tmpnam(3) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at GNU
2008-08-06 MKTEMP(3)

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