Skip to Main Content
UNIX® Shells by Example, Third Edition
book

UNIX® Shells by Example, Third Edition

by Ellie Quigley
October 2001
Intermediate to advanced content levelIntermediate to advanced
1040 pages
22h 50m
English
Pearson
Content preview from UNIX® Shells by Example, Third Edition

12.5. Conditional Constructs and Flow Control

12.5.1. Exit Status

Conditional commands allow you to perform some task(s) based on whether a condition succeeds or fails. The if command is the simplest form of decision-making; the if/else commands allow a two-way decision; and the if/elif/else commands allow a multiway decision.

Bash allows you to test two types of conditions: the success or failure of commands or whether an expression is true or false. In either case, the exit status is always used. An exit status of zero indicates success or true, and an exit status that is nonzero indicates failure or false. The ? status variable contains a numeric value representing the exit status. To refresh your memory on how exit status works, look at ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

UNIX® Shells by Example Fourth Edition

UNIX® Shells by Example Fourth Edition

Ellie Quigley
Storage Area Networks For Dummies®

Storage Area Networks For Dummies®

Christopher Poelker, Alex Nikitin

Publisher Resources

ISBN: 013066538XPurchase book