tmpfile(3p) [centos man page]
TMPFILE(3P) POSIX Programmer's Manual TMPFILE(3P) PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
tmpfile - create a temporary file SYNOPSIS
#include <stdio.h> FILE *tmpfile(void); DESCRIPTION
The tmpfile() function shall create a temporary file and open a corresponding stream. The file shall be automatically deleted when all ref- erences to the file are closed. The file is opened as in fopen() for update (w+). 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. 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. ERRORS
The tmpfile() function shall fail if: EINTR A signal was caught during tmpfile(). EMFILE {OPEN_MAX} file descriptors 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. 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 (); 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 tmp- nam()) and there should be no limit on the number simultaneously open other than this limit and any limit on the number of open files ( {FOPEN_MAX}). RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
fopen(), tmpnam(), unlink(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 at http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 TMPFILE(3P)
Check Out this Related Man Page
TMPNAM(3P) POSIX Programmer's Manual TMPNAM(3P) PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
tmpnam - create a name for a temporary file SYNOPSIS
#include <stdio.h> char *tmpnam(char *s); DESCRIPTION
The tmpnam() function shall generate a string that is a valid filename and that is not the same as the name of an existing file. The func- tion 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. The tmpnam() 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 IEEE Std 1003.1-2001 calls tmpnam(). If the application uses any of the functions guaranteed to be available if either _POSIX_THREAD_SAFE_FUNCTIONS or _POSIX_THREADS is defined, the application shall ensure that the tmpnam() function is called with a non-NULL parameter. RETURN VALUE
Upon successful completion, tmpnam() shall return a pointer to a string. If no suitable string can be generated, the tmpnam() function shall return a null pointer. If the argument s is a null pointer, tmpnam() shall leave its result in an internal static object and return a pointer to that object. Sub- sequent calls to tmpnam() may modify the same object. If the argument s is not a null pointer, it is presumed to point to an array of at least L_tmpnam chars; tmpnam() shall write its result in that array and shall return the argument as its value. ERRORS
No errors are defined. The following sections are informative. EXAMPLES
Generating a Filename The following example generates a unique filename and stores it in the array pointed to by ptr. #include <stdio.h> ... char filename[L_tmpnam+1]; char *ptr; ptr = tmpnam(filename); APPLICATION USAGE
This function only creates filenames. 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. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
fopen(), open(), tempnam(), tmpfile(), unlink(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 at http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 TMPNAM(3P)