grep - In living Color

In my last blog post, I mentioned that in performing software testing you tend to look in log files for clues as to the root cause of bugs. grep is a great tool for doing this, but it does have one drawback. If the lines of text in a log file that you are grep'ing through are very long, you can end up with output that looks like this:

grep here-is-the-bad.jar server.log

22:05:01,485 DEBUG [ServerInfo] class.path: /opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxws.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxrpc.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-saaj.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/serializer.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xercesImpl.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/jaxb-api.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xalan.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/resources.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/rt.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jsse.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jce.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/charsets.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/classes:/usr/lib/here-is-the-bad.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxws.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxrpc.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-saaj.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/serializer.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xercesImpl.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/jaxb-api.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xalan.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/resources.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/rt.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jsse.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jce.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/charsets.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/classes

Oh. Of course. There's the problem. What? You can't see it? ;-)

Let's try that grep command again. But this time, let's use grep's color option*. This will highlight what we're looking for:

grep --color=auto here-is-the-bad.jar server.log

22:05:01,485 DEBUG [ServerInfo] class.path: /opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxws.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxrpc.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-saaj.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/serializer.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xercesImpl.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/jaxb-api.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xalan.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/resources.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/rt.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jsse.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jce.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/charsets.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/classes:/usr/lib/

here-is-the-bad.jar

:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxws.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-jaxrpc.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/server-saaj.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/serializer.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xercesImpl.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/jaxb-api.jar:/opt/local/system000001_test_1234/server-sample-p.1.2.4/server-as/lib/endorsed/xalan.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/resources.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/rt.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jsse.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/jce.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/lib/charsets.jar:/usr/lib/jvm/java-1.6.0-sun-1.6.0.7/jre/classes

Now, that's more like it! ;-)


* Special thanks to Ralph for pointing me at grep's color option!