fseek(3S)                                               fseek(3S)



NAME
     fseek, rewind, ftell - reposition a file pointer in a stream

SYNOPSIS
     #include <stdio.h>

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

     void rewind(stream)
     FILE *stream;

     long ftell(stream)
     FILE *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, when the value of ptrname
     is 0, 1, or 2, respectively.

     rewind(stream) is equivalent to fseek(stream,0L,0), except
     that no value is returned.

     fseek and rewind undo any effects of ungetc(3S).

     After fseek or rewind, the next operation on a file opened
     for update may be either input or output.

     ftell returns the offset of the current byte relative to the
     beginning of the file associated with the named stream.

STATUS MESSAGES AND VALUES
     The fseek program returns non-zero for improper seeks;
     otherwise it returns zero.

     An improper seek can be, for example, an fseek done on a
     file that has not been opened via fopen; in particular,
     fseek may not be used on a terminal or on a file opened via
     popen(3S).

WARNINGS
     On A/UX an offset returned by ftell is measured in bytes,
     and it is permissible to seek to positions relative to that
     offset; however, portability to systems other than A/UX
     requires that an offset be used by fseek directly.
     Arithmetic may not meaningfully be performed on such an
     offset, which is not necessarily measured in bytes.




January 1992                                                    1

fseek(3S)                                               fseek(3S)



SEE ALSO
     lseek(2), fopen(3S), popen(3S), ungetc(3S)





















































2                                                    January 1992