date and time created 88/07/21 17:33:41 by marc

[unix-history] / usr / src / local / tac / tac.1

diff --git a/usr/src/local/tac/tac.1 b/usr/src/local/tac/tac.1
index d8df2b6..0cf06e9 100644 (file)
--- a/usr/src/local/tac/tac.1
+++ b/usr/src/local/tac/tac.1
@@ -1,4 +1,4 @@
-.\"    @(#)tac.1       1.1 %G%
+.\"    @(#)tac.1       1.2 %G%

 .\"
 .TH TAC 1 ""
 .SH NAME
 .\"
 .TH TAC 1 ""
 .SH NAME


@@ -9,7 +9,7 @@ tac \- concatenate and print files in reverse
 .B \-string
 ] [
 .B +string
 .B \-string
 ] [
 .B +string

-] file ...
+] [ file ... ]

 .SH DESCRIPTION
 .I Tac
 reads each
 .SH DESCRIPTION
 .I Tac
 reads each


@@ -27,6 +27,15 @@ specifies right-bounded segments.
 The default is
 .I +\en
 (print lines in reverse order).
 The default is
 .I +\en
 (print lines in reverse order).

+If no input
+.I file
+is given, or if the argument `-'
+is encountered,
+.I tac
+reads from the standard input.  Note that in this case
+.I tac
+stores the entire standard input in a temporary
+file before it outputs anything, so for large input it is slow.

 .SH EXAMPLES
 .RS
 tac '-\e
 .SH EXAMPLES
 .RS
 tac '-\e


@@ -41,16 +50,16 @@ tac file
 prints the file in reverse, line by line, and:
 .PP
 .RS
 prints the file in reverse, line by line, and:
 .PP
 .RS

-tac file1 file2 >file3
+tac /usr/adm/messages | egrep 'hp.*hard'

 .RE
 .RE

-reverses each of the first two files by line and places the
-concatenated result on the third.
+prints out the hard errors on MASSBUS disk drives, most recent first.

 .SH SEE ALSO
 cat(1), rev(1), tail(1), tmail(1)
 .SH BUGS
 .I Tac
 .SH SEE ALSO
 cat(1), rev(1), tail(1), tmail(1)
 .SH BUGS
 .I Tac

-doesn't yet handle multiple argument files exactly right.  It's
-also unclear which direction it should process them in.
+doesn't handle multiple argument files exactly right, and it's
+also unclear in which order they should be processed.

 .br
 .br

-.I Tac
-does not (and cannot efficiently) work on piped input.
+If invoked as `tac < file', 
+.I tac
+uses a temp file but it doesn't have to.