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tmpnam(3p) — Linux manual page

TMPNAM(3P)              POSIX Programmer's ManualTMPNAM(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

       tmpnam — create a name for a temporary file

SYNOPSIS        top

       #include <stdio.h>       char *tmpnam(char *s);

DESCRIPTION        top

       The functionality described on this reference page is aligned with       the ISO C standard. Any conflict between the requirements       described here and the ISO C standard is unintentional. This       volume of POSIX.1‐2017 defers to the ISO C standard.       Thetmpnam() function shall generate a string that is a valid       pathname that does not name an existing file. The function is       potentially capable of generating {TMP_MAX} different strings, but       any or all of them may already be in use by existing files and       thus not be suitable return values.       Thetmpnam() function generates a different string each time it is       called from the same process, up to {TMP_MAX} times. If it is       called more than {TMP_MAX} times, the behavior is implementation-       defined.       The implementation shall behave as if no function defined in this       volume of POSIX.1‐2017, excepttempnam(), callstmpnam().       Thetmpnam() function need not be thread-safe if called with a       NULL parameter.

RETURN VALUE        top

       Upon successful completion,tmpnam() shall return a pointer to a       string. If no suitable string can be generated, thetmpnam()       function shall return a null pointer.       If the arguments is a null pointer,tmpnam() shall leave its       result in an internal static object and return a pointer to that       object. Subsequent calls totmpnam() may modify the same object.       If the arguments is not a null pointer, it is presumed to point       to an array of at least L_tmpnamchars;tmpnam() shall write its       result in that array and shall return the argument as its value.

ERRORS        top

       No errors are defined.The following sections are informative.

EXAMPLES        top

Generating a Pathname       The following example generates a unique pathname and stores it in       the array pointed to byptr.           #include <stdio.h>           ...           char pathname[L_tmpnam+1];           char *ptr;           ptr = tmpnam(pathname);

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(),mkstemp(), ormkdtemp()       functions instead of the obsolescenttmpnam() function.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

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

SEE ALSO        top

fopen(3p),open(3p),mkdtemp(3p),tempnam(3p),tmpfile(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                2017TMPNAM(3P)

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

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