chronic: New command, runs a command quietly, unless it fails.

diff --git a/Makefile b/Makefile
index 377121d56b79b9fbc42cabe86f4c3bae0d44bd2f..3ffd56231826cbcd789361282c329344f54a4f6a 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 BINS=isutf8 ifdata ifne pee sponge mispipe lckdo parallel
-PERLSCRIPTS=vidir vipe ts combine zrun
-MANS=sponge.1 vidir.1 vipe.1 isutf8.1 ts.1 combine.1 ifdata.1 ifne.1 pee.1 zrun.1 mispipe.1 lckdo.1 parallel.1
+PERLSCRIPTS=vidir vipe ts combine zrun chronic
+MANS=sponge.1 vidir.1 vipe.1 isutf8.1 ts.1 combine.1 ifdata.1 ifne.1 pee.1 zrun.1 chronic.1 mispipe.1 lckdo.1 parallel.1
 CFLAGS=-O2 -g -Wall
 INSTALL_BIN?=install -s
 PREFIX=/usr

diff --git a/README b/README
index 548acf2240b3ea1ad6276e39ec195133a8b6d4c6..6a100993aab1cd8ce3a5ba5be9f81b9063270486 100644 (file)
--- a/README
+++ b/README
@@ -1,32 +1,20 @@
 This is a collection of the unix tools that nobody thought to write
 long ago, when unix was young. Currently it consists of these tools:
 
-combine
-       combine the lines in two files using boolean operations
-ifdata
-       get network interface info without parsing ifconfig output
-isutf8
-       check if a file or standard input is utf-8
-ifne
-        run a command if the standard input is not empty
-lckdo
-       execute a program with a lock held (deprecated)
-mispipe
-       pipe two commands, returning the exit status of the first
-parallel
-       run multiple jobs at once
-pee
-       tee standard input to pipes
-sponge
-       soak up standard input and write to a file
-ts
-       timestamp standard input
-vidir
-       edit a directory in your text editor
-vipe
-       insert a text editor into a pipe
-zrun
-       automatically uncompress arguments to command
+chronic: runs a command quietly unless it fails
+combine: combine the lines in two files using boolean operations
+ifdata: get network interface info without parsing ifconfig output
+isutf8: check if a file or standard input is utf-8
+ifne: run a command if the standard input is not empty
+lckdo: execute a program with a lock held (deprecated)
+mispipe: pipe two commands, returning the exit status of the first
+parallel: run multiple jobs at once
+pee: tee standard input to pipes
+sponge: soak up standard input and write to a file
+ts: timestamp standard input
+vidir: edit a directory in your text editor
+vipe: insert a text editor into a pipe
+zrun: automatically uncompress arguments to command
 
 Its web page is here: http://kitenet.net/~joey/code/moreutils/
 

diff --git a/chronic b/chronic
new file mode 100755 (executable)
index 0000000..783b5e0
--- /dev/null
+++ b/chronic
@@ -0,0 +1,63 @@
+#!/usr/bin/perl
+
+=head1 NAME
+
+chronic - runs a command quietly unless it fails
+
+=head1 SYNOPSIS
+
+chronic COMMAND...
+
+=head1 DESCRIPTION
+
+chronic runs a command, and agganges for its standard out and standard
+error to only be displayed if the command fails (exits nonzero or crashes).
+If the command succeeds, any extraneous output will be hidden.
+
+A common use for chronic is for running a cron job. Rather than
+trying to keep the command quiet, and having to deal with mails containing
+accidental output when it succeeds, and not verbose enough output when it
+fails, you can just run it verbosely always, and use chronic to hide
+the successful output.
+
+       5 0 * * * chronic rsync -v foo bar
+
+=head1 AUTHOR
+
+Copyright 2010 by Joey Hess <joey@kitenet.net>
+
+Original concept and "chronic" name by Chuck Houpt.
+
+Licensed under the GNU GPL version 2 or higher.
+
+=cut
+
+use warnings;
+use strict;
+use IPC::Run qw( start pump finish timeout );
+
+if (! @ARGV) {
+       die "usage: chronic COMMAND...\n";
+}
+
+my ($out, $err);
+my $h = IPC::Run::start \@ARGV, \*STDIN, \$out, \$err;
+$h->finish;
+my $ret=$h->full_result;
+
+if ($ret >> 8) { # child failed
+       showout();
+       exit ($ret >> 8);
+}
+elsif ($ret != 0) { # child killed by signal
+       showout();
+       exit 1;
+}
+else {
+       exit 0;
+}
+
+sub showout {
+       print STDOUT $out;
+       print STDERR $err;
+}

diff --git a/debian/changelog b/debian/changelog
index 232f8328e93ffff451b54e19f652a031b145fa7b..958e3804a489be8f77262e7b30677791b362d7a8 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+moreutils (0.43) UNRELEASED; urgency=low
+
+  * chronic: New command, runs a command quietly, unless it fails.
+  * Now depends on IPC::Run, used by chronic.
+
+ -- Joey Hess <joeyh@debian.org>  Fri, 29 Oct 2010 15:23:17 -0400
+
 moreutils (0.42) unstable; urgency=low
 
   * sponge: Guarantee that output file is always updated atomically,

diff --git a/debian/control b/debian/control
index 6af7d481afa37621abc33866c2a1ab1cad1f7eff..451240b5c5f72803e7ef82799f0f849f8f401313 100644 (file)
--- a/debian/control
+++ b/debian/control
@@ -9,7 +9,7 @@ Homepage: http://kitenet.net/~joey/code/moreutils/
 
 Package: moreutils
 Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}, ${perl:Depends}
+Depends: ${shlibs:Depends}, ${misc:Depends}, ${perl:Depends}, libipc-run-perl
 Suggests: libtime-duration-perl, libtimedate-perl
 Conflicts: lckdo
 Replaces: lckdo
@@ -18,6 +18,7 @@ Description: additional Unix utilities
  to write long ago, when Unix was young.
  .
  So far, it includes the following utilities:
+  - chronic: runs a command quietly unless it fails
   - combine: combine the lines in two files using boolean operations
   - ifdata: get network interface info without parsing ifconfig output
   - ifne: run a program if the standard input is not empty