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fseek(3s) [v7 man page]

FSEEK(3S)																 FSEEK(3S)

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(3). 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, 0). SEE ALSO
lseek(2), fopen(3) DIAGNOSTICS
Fseek returns -1 for improper seeks. FSEEK(3S)

Check Out this Related Man Page

FSEEK(3)						     Linux Programmer's Manual							  FSEEK(3)

fgetpos, fseek, fsetpos, ftell, rewind - reposition a stream SYNOPSIS
#include <stdio.h> int fseek(FILE *stream, long offset, int whence); long ftell(FILE *stream); void rewind(FILE *stream); int fgetpos(FILE *stream, fpos_t *pos); int fsetpos(FILE *stream, fpos_t *pos); DESCRIPTION
The fseek function sets the file position indicator for the stream pointed to by stream. The new position, measured in bytes, is obtained by adding offset bytes to the position specified by whence. If whence is set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset is relative to the start of the file, the current position indicator, or end-of-file, respectively. A successful call to the fseek function clears the end-of-file indicator for the stream and undoes any effects of the ungetc(3) function on the same stream. The ftell function obtains the current value of the file position indicator for the stream pointed to by stream. The rewind function sets the file position indicator for the stream pointed to by stream to the beginning of the file. It is equivalent to: (void)fseek(stream, 0L, SEEK_SET) except that the error indicator for the stream is also cleared (see clearerr(3)). The fgetpos and fsetpos functions are alternate interfaces equivalent to ftell and fseek (with whence set to SEEK_SET), setting and storing the current value of the file offset into or from the object referenced by pos. On some non-UNIX systems an fpos_t object may be a complex object and these routines may be the only way to portably reposition a text stream. RETURN VALUE
The rewind function returns no value. Upon successful completion, fgetpos, fseek, fsetpos return 0, and ftell returns the current offset. Otherwise, -1 is returned and the global variable errno is set to indicate the error. ERRORS
EBADF The stream specified is not a seekable stream. EINVAL The whence argument to fseek was not SEEK_SET, SEEK_END, or SEEK_CUR. The function fgetpos, fseek, fsetpos, and ftell may also fail and set errno for any of the errors specified for the routines fflush(3), fstat(2), lseek(2), and malloc(3). CONFORMING TO
The fgetpos, fsetpos, fseek, ftell, and rewind functions conform to ANSI X3.159-1989 (``ANSI C''). SEE ALSO
lseek(2), fseeko(3) BSD MANPAGE
1993-11-29 FSEEK(3)
Man Page

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