Shell Programming and Scripting

Hi, here is my problem. I have a command line tool to process files. Now I have few hundreds of files to process. So I have written a perl script to generate the command dynamically using variables for the arguments. when I use backtick to execute those it creates error. the shell doesn't get the single command fully, it displays error for part of a single command. So I tried writting these commands in a txt file and tried to execute the command by reading line by line using shell script. But, it also creates problem, when I tried reading a file and execute those commands like "pwd and ls" it executes well. but when I tried to run with the commands I have it displays some other things like glibc detected, backtrace and memory map . Please help me. (the commands I have will take take 3 to 5 mins to complete per command)

---------- Post updated at 01:14 PM ---------- Previous update was at 01:01 PM ----------

This is the error I am getting

Code:

19904 Segmentation fault      (core dumped)

Moderator's Comments:

Please use code tags next time for your code and data.

Hi Jith,

You have provided little information here, please try and be a bit more specific. Include things like the version of perl - the operating system, the shell you are using etc. As I'm hoping you're going to respond, what does the code look like and what output do you get from;

Code:

file core

Regards

Dave

Hi, Thanks to both gull04 and the moderator for your comments. I am sorry not to provide sufficient details.

Fortunately I have narrowed down my problem and Im here now :
I am writting a perl script that will run a terminal command and execute something. I this command itself I have @, (, ), \ symbols. when I use backtick perl automatically interpret these things, Now I have escape these characters from perl.
My terminal command is :

Code:

convert_v2 <INPUTFILE_1> -f crop@1920x1079-0+1 -f crop@1920x1080+0+0 -f pixhalf@yonly -f interleave@bottomfield,\( <INPUTFILE_2> -f crop@1920x1080+0+0 -f pixhalf@yinly \) <OUTPUTFILE>

I need to produce the same to be passed to the shell from perl
My perl code is :

Code:

`iconvert_v2 $f1name -f crop\@1920x1079-0+1 -f crop\@1920x1080+0+0 -f pixhalf\@yonly -f interleave\@topfield,\\( $f2name -f crop\@1920x1080+0+0 -f pixhalf\@yonly \\)  $outfil\n`

What I am getting is

Code:

iconvert_v2 FILE1NAME -f cropx1079-0+1 -f cropx1080+0+0 -f pixhalf -f interleave,( FILE2NAME -f cropx1080+0+0 -f pixhalf )  OUTPUTNAME

Can anyone pls help me to get as what I expect. Here the problem is I need perl to interpret only the file name variables nothing else from the command.

---------- Post updated at 02:02 PM ---------- Previous update was at 01:07 PM ----------

Hi thanks fr helping me. I have found a solution for my problem

This is the correct code to produce the expected one!

Code:

qq!iconvert_v2 $f1name -f crop!.q!@1920x1079-0+1 -f crop@1920x1080+0+0 -f pixhalf@yonly -f interleave@topfield,\(!. $f2name .q!-f crop@1920x1080+0+0 -f pixhalf@yonly \)!." $outfil\n"

For the record, you should never get 'segmentation fault' no matter what you do. That means something very unexpected has happened, to the point the programming language wasn't equipped to handle it.

Thanks a lot, I have never aware of it!