FSEEK

Section: Standard I/O Functions (3S)
Updated: December 5, 1987
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NAME

fseek, ftell, rewind - reposition a stream

SYNOPSIS

#include <stdio.h>

fseek(stream, offset, ptrname)
FILE *stream;
long offset;

long ftell(stream)
FILE *stream;

rewind(stream)

DESCRIPTION

Fseek sets the position of the next input or output operation on the stream. The new position is at the signed distance offset bytes from the beginning, the current position, or the end of the file, according as ptrname has the value 0, 1, or 2.

Fseek undoes any effects of ungetc(3S).

Ftell returns the current value of the offset relative to the beginning of the file associated with the named stream. It is measured in bytes on UNIX; on some other systems it is a magic cookie, and the only foolproof way to obtain an offset for fseek.

Rewind(stream) is equivalent to fseek(stream, 0L, L_SET).

DIAGNOSTICS

Fseek returns -1 for improper seeks, otherwise zero.