Free Knowledge Resources


Linux Manual Pages


Free Software * Books

Source Code

Free Media

Linux

tmpnam(3)


NAME

   tmpnam, tmpnam_r - create a name for a temporary file

SYNOPSIS

   #include <stdio.h>

   char *tmpnam(char *s);
   char *tmpnam_r(char *s);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

   tmpnam_r()
       Since glibc 2.19:
           _DEFAULT_SOURCE
       Up to and including glibc 2.19:
           _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

   Note:  avoid  using  these  functions;  use  mkstemp(3)  or  tmpfile(3)
   instead.

   The tmpnam() function returns a pointer to a string  that  is  a  valid
   filename,  and  such  that  a file with this name did not exist at some
   point in time, so that naive programmers may think it a  suitable  name
   for  a  temporary  file.   If  the  argument  s  is  NULL, this name is
   generated in an internal static buffer and may be  overwritten  by  the
   next  call  to  tmpnam().   If s is not NULL, the name is copied to the
   character array (of length at least L_tmpnam) pointed to by s  and  the
   value s is returned in case of success.

   The  created  pathname has a directory prefix P_tmpdir.  (Both L_tmpnam
   and P_tmpdir are defined in <stdio.h>, just like the TMP_MAX  mentioned
   below.)

   The tmpnam_r() function performs the same task as tmpnam(), but returns
   NULL (to indicate an error) if s is NULL.

RETURN VALUE

   These functions return a pointer to a  unique  temporary  filename,  or
   NULL if a unique name cannot be generated.

ERRORS

   No errors are defined.

ATTRIBUTES

   For   an   explanation   of   the  terms  used  in  this  section,  see
   attributes(7).

   
   Interface   Attribute      Value                    
   
   tmpnam()    Thread safety  MT-Unsafe race:tmpnam/!s 
   
   tmpnam_r()  Thread safety  MT-Safe

CONFORMING TO

   tmpnam(): SVr4, 4.3BSD, C89,  C99,  POSIX.1-2001.   POSIX.1-2008  marks
   tmpnam() as obsolete.

   tmpnam_r()  is  a nonstandard extension that is also available on a few
   other systems.

NOTES

   The tmpnam() function generates a different  string  each  time  it  is
   called,  up to TMP_MAX times.  If it is called more than TMP_MAX times,
   the behavior is implementation defined.

   Although these functions generate names that are difficult to guess, it
   is  nevertheless  possible  that  between the time that the pathname is
   returned and the time that the program opens it, another program  might
   create  that  pathname  using open(2), or create it as a symbolic link.
   This can lead to security holes.  To avoid such possibilities, use  the
   open(2)  O_EXCL  flag  to  open  the  pathname.   Or  better  yet,  use
   mkstemp(3) or tmpfile(3).

   Portable applications that use threads cannot call tmpnam() with a NULL
   argument  if  either  _POSIX_THREADS or _POSIX_THREAD_SAFE_FUNCTIONS is
   defined.

BUGS

   Never use these functions.  Use mkstemp(3) or tmpfile(3) instead.

SEE ALSO

   mkstemp(3), mktemp(3), tempnam(3), tmpfile(3)

COLOPHON

   This page is part of release 4.09 of the Linux  man-pages  project.   A
   description  of  the project, information about reporting bugs, and the
   latest    version    of    this    page,    can     be     found     at
   https://www.kernel.org/doc/man-pages/.

                              2016-12-12                         TMPNAM(3)



Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.



Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.



Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.



Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.


birds banner