Print this page. Recommend
Slashdot it! Delicious Digg

Script tuning in Bash

SCRIPT WORKOUT

Author(s): MIRKO DÖLLE

In the old days, shells were capable of little more than calling external programs and executing basic, internal commands. With all the bells and whistles in the latest versions of Bash, however, you hardly need the support of external tools.

Many scripts treat Bash as if it were capable of little more than calling external programs. This is surprising, since version 2 of the default shell has a command set that covers everything from complex string manipulation, through regular expressions, to arrays; useful functions that make expensive program calls redundant. The main advantage of internal functions is that the shell does not need to spawn a new process, which saves processing time and memory. This capability can be important, particularly if you need to launch a program like grep or cut in a loop, as the completion time and memory consumption of a script can explode if you’re not careful. This article describes some simple techiques for speeding up your Bash scripts.


Read full article as PDF »


Comments


Print this page. Recommend
Slashdot it! Delicious Digg
Live Streaming of LISA '08

22nd Large Installation System Administration Conference

If you follow the fortunes of large installation IT, tune in on November 12-14 for a front row ticket to the Invited Talks series of the USENIX LISA conference.

Find out more

 

In the US and Canada, Linux Magazine is known as Linux Pro Magazine.
Entire contents © 2008 [Linux New Media USA, LLC]
Linux New Media web sites:
North America: [Linux Pro Magazine]
UK/Worldwide: [Linux Magazine]
Germany: [Linux-Magazin] [LinuxUser] [EasyLinux] [Linux-Community] [Linux-Nachrichten] [Linux Events]
Eastern Europe: [Linux Magazine Poland] [Linux Community Poland] [Darmowe Programy Poland] [Open Source DVD Poland] [Linux Magazin Romania]
International: [Linux Magazine Brazil] [Linux Magazine Spanish]
Corporate: [Linux New Media AG]