- make SYNOPSIS expand properly

- document -t
- clarify behaviour
- document differences from POSIX

1 files changed, 62 insertions, 5 deletions

diff --git a/usr.bin/expand/expand.1 b/usr.bin/expand/expand.1
index 4929c54710c..da91396cbce 100644
--- a/usr.bin/expand/expand.1
+++ b/usr.bin/expand/expand.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: expand.1,v 1.8 2003/06/03 02:56:07 millert Exp $
+.\"	$OpenBSD: expand.1,v 1.9 2003/10/27 12:24:11 jmc Exp $
 .\"	$NetBSD: expand.1,v 1.3 1995/09/02 06:19:45 jtc Exp $
 .\"
 .\" Copyright (c) 1980, 1990, 1993
@@ -40,15 +40,31 @@
 .Sh SYNOPSIS
 .Nm expand
 .Op Fl Ns Ar tabstop
-.Op Fl Ns Ar tab1 , tab2 , ... , tabn
+.Oo Xo
+.Sm off
+.Fl Ar tab1 , tab2 ,
+.Ar ... , Ar tabn
+.Sm on
+.Oc
+.Xc
+.Op Ar file Ar ...
+.Nm expand
+.Op Fl t Ar tabstop
+.Oo Xo
+.Sm off
+.Fl t\ \& Ar tab1 , tab2 ,
+.Ar ... , Ar tabn
+.Sm on
+.Oc
+.Xc
 .Op Ar file Ar ...
 .Nm unexpand
 .Op Fl a
 .Op Ar file Ar ...
 .Sh DESCRIPTION
 .Nm expand
-processes the named files or the standard input writing
-the standard output with tabs changed into blanks.
+processes the named files or the standard input,
+writing the standard output with tabs changed into blanks.
 Backspace characters are preserved into the output and decrement
 the column count for tab calculations.
 .Nm expand
@@ -61,8 +77,22 @@ If a single
 argument is given, tabs are set
 .Ar tabstop
 spaces apart instead of the default 8.
-If multiple tabstops are given then the tabs are set at those
+If multiple tabstops are given, then the tabs are set at those
 specific columns.
+In the synopsis above, both forms of the
+.Nm
+command are identical.
+.Pp
+If a list of tabstops is given, it should consist of a list
+of two or more positive decimal integers, in ascending order.
+In the event of having to process a
+.Aq tab
+at a position beyond the last of those specified in a multiple tabstop list,
+the
+.Aq tab
+is replaced by a single
+.Aq space
+character.
 .Pp
 .Nm unexpand
 puts tabs back into the data from the standard input or the named
@@ -82,6 +112,33 @@ resultant file by replacing two or more characters.
 .El
 .Sh SEE ALSO
 .Xr fold 1
+.Sh STANDARDS
+The
+.Nm
+and
+.Nm unexpand
+utilities are compliant with the
+.St -p1003.1
+specification, with the following exceptions:
+.Bl -bullet -offset indent
+.It
+.Tn POSIX
+does not support specifying tabstops without use of the
+.Fl t
+flag (first form in
+.Sx SYNOPSIS
+above).
+.It
+.Tn POSIX
+specifies that multiple tabstops may be given separated by
+commas or blanks.
+This implementation supports only comma-separated tabstops.
+.It
+.Nm unexpand
+does not recognise the
+.Fl t
+flag.
+.El
 .Sh HISTORY
 The
 .Nm expand