summaryrefslogtreecommitdiff
path: root/usr.bin
diff options
context:
space:
mode:
Diffstat (limited to 'usr.bin')
-rw-r--r--usr.bin/sed/sed.130
1 files changed, 29 insertions, 1 deletions
diff --git a/usr.bin/sed/sed.1 b/usr.bin/sed/sed.1
index 7b3b81a8c13..4e78ef2a6ae 100644
--- a/usr.bin/sed/sed.1
+++ b/usr.bin/sed/sed.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: sed.1,v 1.42 2014/05/27 07:00:44 jmc Exp $
+.\" $OpenBSD: sed.1,v 1.43 2014/05/27 17:45:02 jmc Exp $
.\"
.\" Copyright (c) 1992, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -507,6 +507,34 @@ option on the command line.
.El
.Sh EXIT STATUS
.Ex -std sed
+.Sh EXAMPLES
+The following simulates the
+.Xr cat 1
+.Fl s
+command,
+squeezing excess empty lines from standard input:
+.Bd -literal -offset indent
+$ sed -n '
+# Write non-empty lines.
+/./ {
+ p
+ d
+ }
+# Write a single empty line, then look for more empty lines.
+/^$/ p
+# Get the next line, discard the held <newline> (empty line),
+# and look for more empty lines.
+:Empty
+/^$/ {
+ N
+ s/.//
+ b Empty
+ }
+# Write the non-empty line before going back to search
+# for the first in a set of empty lines.
+ p
+\&'
+.Ed
.Sh SEE ALSO
.Xr awk 1 ,
.Xr ed 1 ,