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Top Forums UNIX for Dummies Questions & Answers Variable check for existence ? Post 302098633 by samit_9999 on Tuesday 5th of December 2006 02:39:35 PM
Old 12-05-2006
Variable check for existence ?

Hi ,

I have a script wherein i have a For Loop.
Within this for loop i create a variable and assign it a value.

The script goes to a For Loop only if certain conditions are met , which means the variable may or may not exists.

However down the line in the script i have to check if that variable exists on or not.

How do i check this

I tried this but the script fails with the following error "Specify a parameter with this command."
if [ -s ${FILE_LIST} ]
then
echo "Variable Exist"
fi

Please help

Sam
 

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IO::Async::LoopTests(3pm)				User Contributed Perl Documentation				 IO::Async::LoopTests(3pm)

NAME
"IO::Async::LoopTests" - acceptance testing for "IO::Async::Loop" subclasses SYNOPSIS
use IO::Async::LoopTests; run_tests( 'IO::Async::Loop::Shiney', 'io' ); DESCRIPTION
This module contains a collection of test functions for running acceptance tests on IO::Async::Loop subclasses. It is provided as a facility for authors of such subclasses to ensure that the code conforms to the Loop API required by "IO::Async". TIMING
Certain tests require the use of timers or timed delays. Normally these are counted in units of seconds. By setting the environment variable "TEST_QUICK_TIMERS" to some true value, these timers run 10 times quicker, being measured in units of 0.1 seconds instead. This value may be useful when running the tests interactively, to avoid them taking too long. The slower timers are preferred on automated smoke-testing machines, to help guard against false negatives reported simply because of scheduling delays or high system load while testing. TEST_QUICK_TIMERS=1 ./Build test FUNCTIONS
run_tests( $class, @tests ) Runs a test or collection of tests against the loop subclass given. The class being tested is loaded by this function; the containing script does not need to "require" or "use" it first. This function runs "Test::More::plan" to output its expected test count; the containing script should not do this. TEST SUITES
The following test suite names exist, to be passed as a name in the @tests argument to "run_tests": io Tests the Loop's ability to watch filehandles for IO readiness timer Tests the Loop's ability to handle timer events signal Tests the Loop's ability to watch POSIX signals idle Tests the Loop's support for idle handlers child Tests the Loop's support for watching child processes by PID control Tests that the "run", "stop", "loop_once" and "loop_forever" methods behave correctly AUTHOR
Paul Evans <leonerd@leonerd.org.uk> perl v5.14.2 2012-10-24 IO::Async::LoopTests(3pm)
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