Hi Ravinder,
Sorry, but I have to disagree with you here. If the command was:

Code:

	[ -z $logfile ] && logfile=$AMS_LOGFILE

or:

Code:

	test -z $logfile && logfile=$AMS_LOGFILE

or more correctly if written using test:

Code:

	[ -z "$logfile" ] && logfile=$AMS_LOGFILE

or:

Code:

	test -z "$logfile" && logfile=$AMS_LOGFILE

then one would look at the test man page to figure out what the command is doing. But the [[ expression ]] command is part of the syntax of some shells and is not valid in other shells. Therefore, one needs to look at the man page for the shell being used to interpret this script. (It may be that the shell's man page will refer the reader to the test man page for the meaning of some of the expressions it evaluates, but most shells that recognize [[ expression ]] also process some expressions that are not accepted by test.)

Hi AKS_Techie,

Moderator's Comments:

Homework and coursework questions can only be posted in this forum under special homework rules. Please review the rules, which you agreed to when you registered, if you have not already done so. If this is not a homework assignment, please explain the nature of the problem you are working on. If this is a homework assignment, please review the guidelines for posting homework and repost in the correct forum.

Note also that the code you have posted sort of looks like a shell function definition, but is not in the correct format and is likely to generate a syntax error.

And, like [[ expression ]], local is another part of the shell language in some shells and a syntax error in others. As such, you'll need to look at your shell's man page to determine what local does, if anything.

Whenever your start a thread in the UNIX.com forums please tell us what operating system and shell you're using so we can make educated guesses at what your programming environment is. Without that basic information, we may make lots of suggestions that will not work in your environment.