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tempnam(3p) — Linux manual page

TEMPNAM(3P)             POSIX Programmer's ManualTEMPNAM(3P)

PROLOG        top

       This manual page is part of the POSIX Programmer's Manual.  The       Linux implementation of this interface may differ (consult the       corresponding Linux manual page for details of Linux behavior), or       the interface may not be implemented on Linux.

NAME        top

       tempnam — create a name for a temporary file

SYNOPSIS        top

       #include <stdio.h>       char *tempnam(const char *dir, const char *pfx);

DESCRIPTION        top

       Thetempnam() function shall generate a pathname that may be used       for a temporary file.       Thetempnam() function allows the user to control the choice of a       directory. Thedir argument points to the name of the directory in       which the file is to be created. Ifdir is a null pointer or       points to a string which is not a name for an appropriate       directory, the path prefix defined as P_tmpdir in the<stdio.h>       header shall be used. If that directory is not accessible, an       implementation-defined directory may be used.       Many applications prefer their temporary files to have certain       initial letter sequences in their names. Thepfx argument should       be used for this. This argument may be a null pointer or point to       a string of up to five bytes to be used as the beginning of the       filename.       Some implementations oftempnam() may usetmpnam() internally. On       such implementations, if called more than {TMP_MAX} times in a       single process, the behavior is implementation-defined.

RETURN VALUE        top

       Upon successful completion,tempnam() shall allocate space for a       string, put the generated pathname in that space, and return a       pointer to it. The pointer shall be suitable for use in a       subsequent call tofree().  Otherwise, it shall return a null       pointer and seterrno to indicate the error.

ERRORS        top

       Thetempnam() function shall fail if:ENOMEMInsufficient storage space is available.The following sections are informative.

EXAMPLES        top

Generating a Pathname       The following example generates a pathname for a temporary file in       directory/tmp, with the prefixfile.  After the pathname has been       created, the call tofree() deallocates the space used to store       the pathname.           #include <stdio.h>           #include <stdlib.h>           ...           const char *directory = "/tmp";           const char *fileprefix = "file";           char *file;           file = tempnam(directory, fileprefix);           free(file);

APPLICATION USAGE        top

       This function only creates pathnames. It is the application's       responsibility to create and remove the files. Between the time a       pathname is created and the file is opened, it is possible for       some other process to create a file with the same name.       Applications may findtmpfile() more useful.       Applications should use thetmpfile(),mkdtemp(), ormkstemp()       functions instead of the obsolescenttempnam() function.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       Thetempnam() function may be removed in a future version.

SEE ALSO        top

fopen(3p),free(3p),mkdtemp(3p),open(3p),tmpfile(3p),tmpnam(3p),unlink(3p)       The Base Definitions volume of POSIX.1‐2017,stdio.h(0p)

COPYRIGHT        top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 by the Institute of Electrical and Electronics Engineers,       Inc and The Open Group.  In the event of any discrepancy between       this version and the original IEEE and The Open Group Standard,       the original IEEE and The Open Group Standard is the referee       document. The original Standard can be obtained online athttp://www.opengroup.org/unix/online.html .       Any typographical or formatting errors that appear in this page       are most likely to have been introduced during the conversion of       the source files to man page format. To report such errors, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017TEMPNAM(3P)

Pages that refer to this page:stdio.h(0p), tmpnam(3p)

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