создать временный файл (create 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)
tmpfile — create a temporary file
Синопсис (Synopsis)
#include <stdio.h>
FILE *tmpfile(void);
Описание (Description)
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.
The tmpfile() function shall create a temporary file and open a
corresponding stream. The file shall be automatically deleted
when all references to the file are closed. The file shall be
opened as in fopen() for update (wb+), except that
implementations may restrict the permissions, either by clearing
the file mode bits or setting them to the value S_IRUSR |
S_IWUSR.
In some implementations, a permanent file may be left behind if
the process calling tmpfile() is killed while it is processing a
call to tmpfile().
An error message may be written to standard error if the stream
cannot be opened.
Возвращаемое значение (Return value)
Upon successful completion, tmpfile() shall return a pointer to
the stream of the file that is created. Otherwise, it shall
return a null pointer and set errno to indicate the error.
Ошибки (Error)
The tmpfile() function shall fail if:
EINTR A signal was caught during tmpfile().
EMFILE All file descriptors available to the process are
currently open.
EMFILE {STREAM_MAX} streams are currently open in the calling
process.
ENFILE The maximum allowable number of files is currently open in
the system.
ENOSPC The directory or file system which would contain the new
file cannot be expanded.
EOVERFLOW
The file is a regular file and the size of the file cannot
be represented correctly in an object of type off_t.
The tmpfile() function may fail if:
EMFILE {FOPEN_MAX} streams are currently open in the calling
process.
ENOMEM Insufficient storage space is available.
The following sections are informative.
Примеры (Examples)
Creating a Temporary File
The following example creates a temporary file for update, and
returns a pointer to a stream for the created file in the fp
variable.
#include <stdio.h>
...
FILE *fp;
fp = tmpfile ();
Использование в приложениях (Application usage)
It should be possible to open at least {TMP_MAX} temporary files
during the lifetime of the program (this limit may be shared with
tmpnam()) and there should be no limit on the number
simultaneously open other than this limit and any limit on the
number of open file descriptors or streams ({OPEN_MAX},
{FOPEN_MAX}, {STREAM_MAX}).
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
Section 2.5, Standard I/O Streams, fopen(3p), mkdtemp(3p),
tmpnam(3p), unlink(3p)
The Base Definitions volume of POSIX.1‐2017, stdio.h(0p)
