создать имя для временного файла (create a name for a temporary file)
Пролог (Prolog)
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.
Имя (Name)
tempnam — create a name for a temporary file
Синопсис (Synopsis)
#include <stdio.h>
char *tempnam(const char *dir, const char *pfx);
Описание (Description)
The tempnam() function shall generate a pathname that may be used
for a temporary file.
The tempnam() function allows the user to control the choice of a
directory. The dir argument points to the name of the directory
in which the file is to be created. If dir 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. The pfx 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 of tempnam() may use tmpnam() internally. On
such implementations, if called more than {TMP_MAX} times in a
single process, the behavior is implementation-defined.
Возвращаемое значение (Return value)
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 to free(). Otherwise, it shall return a null
pointer and set errno to indicate the error.
Ошибки (Error)
The tempnam() function shall fail if:
ENOMEM
Insufficient storage space is available.
The following sections are informative.
Примеры (Examples)
Generating a Pathname
The following example generates a pathname for a temporary file
in directory /tmp
, with the prefix file. After the pathname has
been created, the call to free() 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);
Использование в приложениях (Application usage)
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 find tmpfile() more useful.
Applications should use the tmpfile(), mkdtemp(), or mkstemp()
functions instead of the obsolescent tempnam() function.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
The tempnam() function may be removed in a future version.
Смотри также (See also)
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)