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Dialects of English and Unix

Archive - Originally posted on "The Horse's Mouth" - 2008-08-21 17:56:41 - Graham Ellis

English is spoken as a first language by over 300 million people, and by about five times that number if you include people who can speak it as a second or third language. But that doesn't mean that word and wording is going to be the same within different variants, let alone the subtleties and drifts, where somethings that's just a mild comment in English can be offensive to an American, and vice versa.

In a way, it's a bit the same with flavours of Unix and Linux - something that works on Solaris may not work on OS X, and a Linux command that you've come to rely on on your shared hosting service turns out to have not been loaded on the basic build on your new dedicated host - ah - these things are sent to try us!

Take the ps command - for process status,

In the old SunOS 4.1.3 days, it used to be second nature to type ps -aux but that was a Berkeley Software Distribution (bsd) based Unix and when Sun switched to System V.4 (AT&T based) at Solaris 2 / SunOS 5, the recommended command became ps elf which presented broadly the same information is a somewhat different format.

You'll notice that the - (minus sign) has gone from the "option" list, and I recall being told that happened because they're not really options, but rather they are a description of how the thing is to work. And if they're not options, you don't need a minus sign! ((The same thing applies to tar - where it's tar cvf rather than tar -cvf))

There days, under Linux, I find some delegates using ps ef and others using ps aux. But there are other useful options ... and I surprised one of my delegates by suggesting he use

ps auxwww

Odd? Yes, it is a bit. The "w" descriptor means "wide" - or in this case "wide, wide, wide" ... so that lines reported are not truncated to the screen width. ps auxwww outputs the complete command line used to start all processes, and in this instance was vital to allow my delegate to see all the various options used in starting up Tomcat, including the option that specified which particular JVM release it was to use, and where that was to be loaded from.