.\" As its sole author, I explicitly place this file in the public domain.
.\" It may be used by anyone in any way for any purpose, though I would
.\" appreciate credit where it's due.
.\"		der Mouse, mouse@rodents.montreal.qc.ca, 1999-10-13
.Dd October 13, 1999
.Dt LSEEK 1
.Os NetBSD 1.4
.Sh NAME
.Nm lseek
.Nd stream repositioning utility
.Sh SYNOPSIS
.Nm
.Op Fl set
.Op Fl cur
.Op Fl end
.Op Fl incr
.Op Fl xtnd
.Ar fd
.Ar offset
.Sh DESCRIPTION
.Nm
is a small tool to reposition streams.  It is just a command-line
interface to
.Xr lseek 2 .
It is normally used to position a file descriptor as desired before
running some other program (such as
.Xr dd 1 ) ,
as in
.Dl % (lseek 0 8192; dd bs=1048576 of=...) < /dev/...
.Pp
The
.Ar fd
argument specifies the file descriptor the seek is done on, such as 0
for standard input or 1 for standard output.  The
.Ar offset
argument specifies the offset to seek to.  By default, the third
argument to
.Xr lseek 2
is
.Dv SEEK_SET ;
to change this, one of
.Fl set ,
.Fl cur ,
or
.Fl end
may be given, to specify
.Dv SEEK_SET ,
.Dv SEEK_CUR ,
or
.Dv SEEK_END ,
respectively.  (The
.Fl incr
and
.Fl xtnd
names are for compatability with the old
.Dv L_INCR
and
.Dv L_XTND
names for
.Dv SEEK_CUR
and
.Dv SEEK_END ;
.Fl incr
is equivalent to
.Fl cur
and
.Fl xtnd
is equivalent to
.Fl end . )
If conflicting specifiers are given, the one appearing last on the
command line wins.
.Pp
.Fl q
specifies that
.Nm
is to run quietly.  When this is given and
.Xr lseek 2
fails, instead of printing an error and exiting with status 2,
.Nm
prints nothing and exits with exit status equal to the system error
number returned (see
.Xr errno 2 ) .
With
.Fl q ,
command-line errors produce a complaint on standard error and an exit
status of
.Dv EINVAL .
(Note that this applies only to errors occurring after the
.Fl q
option itself.)  Without
.Fl q ,
command-line errors provoke an exit status of 1 (and a complaint on
standard error) and
.Xr lseek 2
failures produce a complaint on standard error and exit status 2.  In
all cases, if there is no error, the exit status is zero and nothing is
printed.
.Sh AUTHOR
der Mouse,
.Aq mouse@rodents.montreal.qc.ca .