How to catch Command Line Tool errors using Perl

fallinj

I want to make sure that I can catch and report any errors I get from a CLT when called from a Perl script. I'm running TeamSite 5.0 on Windows 2000.

I will use iwgen as an example. If I try and run the following command (with intentional bad arguments) from the DOS prompt I know I will get an error from the iwgen program.

c:\iw-home\bin\iwgen -t jkjd -r jksd jljf.html
Returns:
jkjd: not a TeamSite Templating presentation template

If I try and do this from a Perl Script I want to be able to catch that error string. I've tried doing this using the $?, $!, $^E, and $@ sepecial variables but with no luck.

Here's a test Perl script

$cmd = "C:\\iw-home\\bin\\iwgen -t jkjd -r jksd jljf.html";
$result = `$cmd`;
print "\$result = $result\n";
print "\$? = $?\n";
print "\$! = $!\n";
print "\$^E = $^E\n";
print "\$\@ = $@\n";

When I run this I get the following:

$result =
$? = 0
$! =
$^E = The pipe has been ended
$@ =

I know that because $? = 0 that the CLT failed but I don't know exactly why. Where is the error string
"jkjd: not a TeamSite Templating presentation template" ?

How can I trap that in my perl script?

laj1

You need the old "redirect stderr into sdtout" trick.
It looks like this (your milage may vary):

mycommand > outputfile 2>&1

this basically says send stdout to outputfile, and send stderr to the same place stdout is going.

Then, when the command is done, examine the contents of outputfile.

Len Jaffe
My Heart Is A Flower