[SOLVED] Quoting and escaping

divyashree · 02-25-2014, 12:33 AM

I have a shell script, the arguments of which are collected in quote as a singlle argument and passed that single arg. to a perl script inside.

I want to give a n argument like this:

Code:

"Test Internal Cluster"

to the perl script.

When I am using

Code:

"Test\ Internal\ Cluster"

argument to the shell script its passing as

Code:

Test Internal Cluster

to the perl script, but I want that to be in double quotes.
This seems simple but not able to use proper quoting and escaping to achieve.

grail · 02-25-2014, 01:27 AM

Maybe you could show the snippet in both bash and Perl that receive and send this information?

divyashree · 02-25-2014, 01:31 AM

Quote:

Originally Posted by grail

Maybe you could show the snippet in both bash and Perl that receive and send this information?

Here is the shell script:

Code:

#!/bin/bash -xv

Perl=/usr/bin/perl
Api=/usr/local/API/check_api.pl

if [ $# -gt 0 ]; then
  if [ -x $Api ]
   then
        output=$($Perl $Api $1)
        exitstatus=$?
        F1=$(echo $output | awk -F':' '{print $1}')
        F2=$(echo $output | awk -F':' '{print $2}' | awk -F'|' '{print $1}')
        F3=$(echo $output | awk -F':' '{print $2}' | awk -F'|' '{print $2}')
        echo " $F1: $F3 | $F2"
  else
        echo "check_api.pl not found"
 fi
 exit $exitstatus
else
    echo "Usage : $0 '-D <DC> -C <Cluster> -u <userbame> -p <password> -i <interval> -l <command>  -s <subcommand>'"
fi

Here you can see the whole argument passed to shell script is collected to $1 and passed to the check_api perl script.

The issue is happening with cluster name with space(passed to -C).

And the wholeargument passed to the shell script should be in single/double quote.

grail · 02-25-2014, 02:05 AM

And why are your variables not quoted?

Code:

output=$($Perl $Api "$1")

It also seems a little weird that you retrieve the "exitstatus", but never test it and then call it to be used when it may in fact not be set at all (ie it is outside the 'if' where it gets set)

You test "$Api" to be executable by the user running the script but your error says that it has not been found. What if it were only executable by root? What if it exists but is not executable at all?

Lastly, have a look at parameter substitution as all of those calls to awk seem to be a huge over kill. If you can provide dummy data that might exist in "output" I can probably help

divyashree · 02-25-2014, 02:55 AM

Quote:

Originally Posted by grail

And why are your variables not quoted?

Code:

output=$($Perl $Api "$1")

It also seems a little weird that you retrieve the "exitstatus", but never test it and then call it to be used when it may in fact not be set at all (ie it is outside the 'if' where it gets set)

You test "$Api" to be executable by the user running the script but your error says that it has not been found. What if it were only executable by root? What if it exists but is not executable at all?

Lastly, have a look at parameter substitution as all of those calls to awk seem to be a huge over kill. If you can provide dummy data that might exist in "output" I can probably help

Hi grail, Thanks for the reply.

I haven't quoted the variable $1 because the perlscript is not accepting the whole argument as a single as below which I found in debug mode - where the whole argument is quoted if $1 is quoted.

Code:

/usr/bin/perl /usr/local/check_api.pl '-D x.x.x.x -C Test_Internal_Cluster -u user -p pass  -i 300 -l runtime -s list'

and throws error as incorrect usage

But without quoting the $1 the argument passed to perl script works like this and which gives me the result:

Code:

/usr/bin/perl /usr/local/check_api.pl -D x.x.x.x -C Test_Internal_Cluster -u user -p pass -i 300 -l runtime -s list

But I am failed with a cluster with space in its name.

In case of a space in cluster name if I am running in the command line directly(not from shell script) it works fine without any issue:

Code:

/usr/bin/perl /usr/local/check_api.pl -D x.x.x.x -C "Test Internal Cluster" -u user -p pass -i 300 -l runtime -s list

which I wanted to achieve from shell script.

chrism01 · 02-25-2014, 05:00 AM

So why not do that then; the shell script is redundant.

pan64 · 02-25-2014, 05:58 AM

You have all the arguments put into $1, actually you can handle it in one or split by white spaces. But if you want to keep some words together you need to implement a special handler to it - or pass the arguments one by one and not in a single string.

grail · 02-25-2014, 07:32 AM

I am with others in not really seeing the point of the script, however, you can simply pass the line as is, ie:

Code:

-D x.x.x.x -C '"Test Internal Cluster"' -u user -p pass -i 300 -l runtime -s list

Then you can simply refer to $@ which will be all of your arguments

divyashree · 02-26-2014, 09:45 PM

Thanks to all for your valuable inputs. I rewrote the script using getopts to pass one by one argument and it worked like charm.