freopen
---open a file using an existing file descriptor#include <stdio.h> FILE *freopen(const char *file, const char *mode, FILE *fp);Description
fopen
if you wish to specify a particular file
descriptor fp (notably stdin
, stdout
, or stderr
) for
the file.
If fp was associated with another file or stream, freopen
closes that other file or stream (but ignores any errors while closing
it).
file and mode are used just as in fopen
.
Returns
If successful, the result is the same as the argument fp. If the
file cannot be opened as specified, the result is NULL
.
Portability
ANSI C requires freopen
.
Supporting OS subroutines required: close
, fstat
, isatty
,
lseek
, open
, read
, sbrk
, write
.