NAME
fgetpos, fseek, fsetpos, ftell, rewind - reposition a stream SYNOPSIS
#include
int fseek(FILE *stream, long offset, int whence); long ftell(FILE *stream); void rewind(FILE *stream); int fgetpos(FILE *stream, fpost *pos); int fsetpos(FILE *stream, fpost *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 SEEKSET, SEEKCUR, or SEEKEND, 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, SEEKSET) except that the error indicator for the stream is also cleared (see clearerr(3)). The fgetpos() and fsetpos() functions are alternate interfaces equiva‐ lent to ftell() and fseek() (with whence set to SEEKSET), setting and storing the current value of the file offset into or from the object
referenced by pos. On some non-UNIX systems, an fpost object may be a complex object and these routines may be the only way to portably repo‐ sition 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 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 SEEKSET, SEEKEND, or SEEKCUR. The functions 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 C89, C99. SEE ALSO lseek(2), fseeko(3) COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 1993-11-29 FSEEK(3)