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tempnam(3)              Library Functions Manual              tempnam(3)

ИМЯ

       tempnam - create a name for a temporary file

БИБЛИОТЕКА

       Standard C library (libc, -lc)

СИНТАКСИС

       #include <stdio.h>

       char *tempnam(const char *dir, const char *pfx);

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

       tempnam():
           Since glibc 2.19:
               _DEFAULT_SOURCE
           glibc 2.19 and earlier:
               _BSD_SOURCE || _SVID_SOURCE

ОПИСАНИЕ

       Never use this function.  Use mkstemp(3) or tmpfile(3) instead.

       The tempnam() function returns a pointer to a string that is a
       valid filename, and such that a file with this name did not exist
       when tempnam() checked.  The filename suffix of the pathname
       generated will start with pfx in case pfx is a non-NULL string of
       at most five bytes.  The directory prefix part of the pathname
       generated is required to be "appropriate" (often that at least
       implies writable).

       Attempts to find an appropriate directory go through the
       following steps:

       a) In case the environment variable TMPDIR exists and contains
          the name of an appropriate directory, that is used.

       b) Otherwise, if the dir argument is non-NULL and appropriate, it
          is used.

       c) Otherwise, P_tmpdir (as defined in <stdio.h>) is used when
          appropriate.

       d) Finally an implementation-defined directory may be used.

       The string returned by tempnam() is allocated using malloc(3) and
       hence should be freed by free(3).

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       On success, the tempnam() function returns a pointer to a unique
       temporary filename.  It returns NULL if a unique name cannot be
       generated, with errno set to indicate the error.

ОШИБКИ

       ENOMEM Allocation of storage failed.

АТРИБУТЫ

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────┬───────────────┬─────────────┐
       │ Interface                       │ Attribute     │ Value       │
       ├─────────────────────────────────┼───────────────┼─────────────┤
       │ tempnam()                       │ Thread safety │ MT-Safe env │
       └─────────────────────────────────┴───────────────┴─────────────┘

СТАНДАРТЫ

       POSIX.1-2008.

ИСТОРИЯ

       SVr4, 4.3BSD, POSIX.1-2001.  Obsoleted in POSIX.1-2008.

ПРИМЕЧАНИЯ

       Although tempnam() generates names that are difficult to guess,
       it is nevertheless possible that between the time that tempnam()
       returns a pathname, 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).

       SUSv2 does not mention the use of TMPDIR; glibc will use it only
       when the program is not set-user-ID.  On SVr4, the directory used
       under d) is /tmp (and this is what glibc does).

       Because it dynamically allocates memory used to return the
       pathname, tempnam() is reentrant, and thus thread safe, unlike
       tmpnam(3).

       The tempnam() function generates a different string each time it
       is called, up to TMP_MAX (defined in <stdio.h>) times.  If it is
       called more than TMP_MAX times, the behavior is implementation
       defined.

       tempnam() uses at most the first five bytes from pfx.

       The glibc implementation of tempnam() fails with the error EEXIST
       upon failure to find a unique name.

ОШИБКИ

       The precise meaning of "appropriate" is undefined; it is
       unspecified how accessibility of a directory is determined.

СМОТРИТЕ ТАКЖЕ

       mkstemp(3), mktemp(3), tmpfile(3), tmpnam(3)

КОЛОФОН

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
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       2024-06-26.  If you discover any rendering problems in this HTML
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       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                     tempnam(3)

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