fseek(3)                            CLIX                            fseek(3)



  NAME

    fseek, rewind, ftell - Repositions a file pointer in a stream

  LIBRARY

    Standard C Library (libc.a)

  SYNOPSIS

    #include <stdio.h>

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

    void rewind(
      FILE *stream );

    long ftell(
      FILE *stream );

  PARAMETERS

    stream    Points to a file.

    offset    Specifies the number of bytes from a specified location in the
              file.

    ptrname   Specifies the position to begin I/O on a stream.

  DESCRIPTION

    The fseek() function 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, from the current position, or from the
    end of the file, according as ptrname has the value 0, 1, or 2.

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

    The fseek() and rewind() functions undo any effects of ungetc().  After
    fseek() or rewind(), the next operation on a file opened for update may be
    either input or output.

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

  CAUTIONS




  2/94 - Intergraph Corporation                                              1

  fseek(3)                            CLIX                            fseek(3)



    Although on the UNIX system an offset returned by ftell() is measured in
    bytes, and it is permissible to seek positions relative to that offset,
    portability to non-UNIX systems 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.

  RETURN VALUES

    The fseek() function returns nonzero for improper seeks, or 0 otherwise.
    An improper seek can be, for example, an fseek() done on a file that has
    not been opened with fopen(); in particular, fseek() may not be used on a
    terminal, or on a file opened with popen().

  RELATED INFORMATION

    Functions:  lseek(2), fopen(3), popen(3), ungetc(3), stdio(3)






































  2                                              Intergraph Corporation - 2/94