tmpfile

 

C

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Standard Library

Type support

Dynamic memory management

Error handling

Program utilities

Date and time utilities

Strings library

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Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

 

File input/output

Functions
File access
fopen freopen fclose fflush	fwide setbuf setvbuf
Direct input/output
fread
fwrite
Unformatted input/output
fgetc fgets fputc fputs getchar gets putchar puts ungetc	fgetwc fgetws fputwc fputws getwchar putwchar ungetwc
Formatted input/output
scanffscanfsscanf vscanfvfscanfvsscanf (C99)(C99)(C99) printffprintfsprintfsnprintf (C99) vprintfvfprintfvsprintfvsnprintf (C99)	wscanffwscanfswscanf vwscanfvfwscanfvswscanf (C99)(C99)(C99) wprintffwprintfswprintf vwprintfvfwprintfvswprintf
File positioning
ftell
fgetpos
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rewind
Error handling
clearerr
feof
ferror
perror
Operations on files
remove
rename
tmpfile
tmpnam

 

Defined in header <stdio.h>
FILE *tmpfile();

Opens a temporary file. The file is opened as binary file for update ("wb+ mode). The filename of the file is guaranteed to be unique within the filesystem.

The file will be closed when the program exits.

Parameters

(none)

Return value

The associated file stream or NULL if an error has occurred

Example

tmpfile with error checking. Code opens a temporary file with mode "wb+".

Run this code

#include <stdio.h>
#include <stdlib.h>
 
int main(void)
{
    FILE* tmpf = tmpfile();   /* mode: "wb+" */
    if (tmpf == NULL)
    {
       perror("tmpfile()");
       fprintf(stderr,"tmpfile() failed in file %s at line # %d", __FILE__,__LINE__-4);
       exit(EXIT_FAILURE);
    }
    fputs("Hello, world", tmpf);
    rewind(tmpf);
    char buf[6];
    fgets(buf, sizeof buf, tmpf);
    printf("%s\n", buf);
 
    return EXIT_SUCCESS;
}

Output:

Hello

See also

tmpnam	returns a unique filename (function)
C++ documentation for tmpfile