fgetpos---record position in a stream or file#include <stdio.h> int fgetpos(FILE *fp, fpos_t *pos);Description
FILE can have a "position" that records how much
of the file your program has already read. Many of the stdio functions
depend on this position, and many change it as a side effect.
You can use fgetpos to report on the current position for a file
identified by fp; fgetpos will write a value
representing that position at *pos. Later, you can
use this value with fsetpos to return the file to this
position.
In the current implementation, fgetpos simply uses a character
count to represent the file position; this is the same number that
would be returned by ftell.
Returns
fgetpos returns 0 when successful. If fgetpos fails, the
result is 1. Failure occurs on streams that do not support
positioning; the global errno indicates this condition with the
value ESPIPE.
Portability
fgetpos is required by the ANSI C standard, but the meaning of the
value it records is not specified beyond requiring that it be
acceptable as an argument to fsetpos. In particular, other
conforming C implementations may return a different result from
ftell than what fgetpos writes at *pos.
No supporting OS subroutines are required.