All,
I have a sh script of the following tune:
function a () { #functionality.. }
function b () { #functionnlity.. }
function check () { # this function checks for env and if all fine call build }
function usage () { #sh usage details }
function build () { #calls either a or b or... (5 Replies)
Simple shell script :
date
test_fn()
{
echo "function within test shell script "
}
on the shell prompt I run
> . test
Then I invoke the function on the command line as below :
test_fn()
It echos the line
function within test shell script
and works as expected.
... (5 Replies)
i've been told that c shell does not support functions/subroutines is that true?
if not can somebody give me the basic syntax for creating a function. it would very much appreciated!
thanks in advance (1 Reply)
Hi All,
I have a very long code called myfunction -> "if ..... else if .... else if ..end if "
And i have several other codes which need to call the "myfunction" code.
How can C-shell call a function "B]myfunction" ? Can any body give me an example ?? (1 Reply)
Hi,
I have a query ..
i have 2 scripts say 1.sh and 2.sh
1.sh contains many functions written using shell scripts.
2.sh is a script which needs to call the functions definded in 1.sh
function calls are with arguments.
Can some one tell me how to call the functions from 2.sh?
Thanks in... (6 Replies)
Hi I have 2 files a.c and a.bak where I changed long to int using awk script.
I want to get the list of functions whose parameters got modified
for eg: fun ( long a, long b ) might be changed to fun ( int a, int b ) (1 Reply)
Hi All,
I'm pretty new to the forum and also to UNIX. I have a requirement for which I need some help. I have a script (example.script) where I get user inputs using the read command. I would need to pass the read-fetched input to a perl command (explained below) in my script. The part which... (3 Replies)
I have 7 functions those need to be executed as command line inputs, I tried with below code it’s not executing function. If I run the ./script 2 then fun2 should execute , how to initiate that function I tried case and if else also, how to initiate function from command line
if
then... (8 Replies)
Hi ,
I have a script which is using a text file as I/P.
I want a code where it reads n lines from this file and pass the parameters to a function and now this script should run in such a way where a function can be called in parallel with different parameters. Please find below my script, it... (1 Reply)
Hi,
I am a beginner in python programming. In my python script have a main function which calls several other functions. The main function gets its input by reading lines from a input text file. I call the main function for every line in input text file through a loop.
def main(line):
var1... (6 Replies)
Perl::Critic::Policy::ErrorHandling::RequireCheckingRetuUserlContributedPerl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval(3pm)NAME
Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval - You can't depend upon the value of "$@"/"$EVAL_ERROR" to tell
whether an "eval" failed.
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
A common idiom in perl for dealing with possible errors is to use "eval" followed by a check of $@/$EVAL_ERROR:
eval {
...
};
if ($EVAL_ERROR) {
...
}
There's a problem with this: the value of $EVAL_ERROR can change between the end of the "eval" and the "if" statement. The issue is object
destructors:
package Foo;
...
sub DESTROY {
...
eval { ... };
...
}
package main;
eval {
my $foo = Foo->new();
...
};
if ($EVAL_ERROR) {
...
}
Assuming there are no other references to $foo created, when the "eval" block in "main" is exited, "Foo::DESTROY()" will be invoked,
regardless of whether the "eval" finished normally or not. If the "eval" in "main" fails, but the "eval" in "Foo::DESTROY()" succeeds,
then $EVAL_ERROR will be empty by the time that the "if" is executed. Additional issues arise if you depend upon the exact contents of
$EVAL_ERROR and both "eval"s fail, because the messages from both will be concatenated.
Even if there isn't an "eval" directly in the "DESTROY()" method code, it may invoke code that does use "eval" or otherwise affects
$EVAL_ERROR.
The solution is to ensure that, upon normal exit, an "eval" returns a true value and to test that value:
# Constructors are no problem.
my $object = eval { Class->new() };
# To cover the possiblity that an operation may correctly return a
# false value, end the block with "1":
if ( eval { something(); 1 } ) {
...
}
eval {
...
1;
}
or do {
# Error handling here
};
Unfortunately, you can't use the "defined" function to test the result; "eval" returns an empty string on failure.
Various modules have been written to take some of the pain out of properly localizing and checking $@/$EVAL_ERROR. For example:
use Try::Tiny;
try {
...
} catch {
# Error handling here;
# The exception is in $_/$ARG, not $@/$EVAL_ERROR.
}; # Note semicolon.
"But we don't use DESTROY() anywhere in our code!" you say. That may be the case, but do any of the third-party modules you use have them?
What about any you may use in the future or updated versions of the ones you already use?
CONFIGURATION
This Policy is not configurable except for the standard options.
SEE ALSO
See thread on perl5-porters starting here: http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2008-06/msg00537.html
<http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2008-06/msg00537.html>.
For a nice, easy, non-magical way of properly handling exceptions, see Try::Tiny.
AUTHOR
Elliot Shank "<perl@galumph.com>"
COPYRIGHT
Copyright (c) 2008-2011 Elliot Shank.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license
can be found in the LICENSE file included with this module.
perl v5.14.22012Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval(3pm)