catch error code from system()

[justme]

hi

i wrote a perl script that is supposed to run a java program.

my $cmd ="/usr/bin/java javaprog";
system($cmd);

the java prog returns an error code if there is an error when the java prog runs
how can i catch the return code of the java prog reliably ?
thanks

 

[Sam Holden]

hi

i wrote a perl script that is supposed to run a java program.

my $cmd ="/usr/bin/java javaprog";
system($cmd);

the java prog returns an error code if there is an error when the java prog runs
how can i catch the return code of the java prog reliably ?
thanks

What does the documentation for the perl system function say?

 

[Paul Lalli]

hi

i wrote a perl script that is supposed to run a java program.

my $cmd ="/usr/bin/java javaprog";
system($cmd);

the java prog returns an error code if there is an error when the java prog runs
how can i catch the return code of the java prog reliably ?
thanks

Uhm, by not throwing away the return value from system?

my $retval = system($cmd);

(note that one more step is actually needed. Read
perldoc -f system
for more info)

Paul Lalli

 

[Jürgen Exner]

i wrote a perl script that is supposed to run a java program.

my $cmd ="/usr/bin/java javaprog";
system($cmd);

the java prog returns an error code if there is an error when the
java prog runs how can i catch the return code of the java prog
reliably ? thanks

Please provide a complete but minimal program that demonstrates that the
method described in the documentation for system() doesn't work.
Then people will sure be happy to investigate.

jue

 

[Tad McClellan]

how can i catch the return code of the java prog reliably ?

Please do not ask thousands of people to read the docs to you.


perldoc -f system

 

[J. Romano]

i wrote a perl script that is supposed to run a java program.

my $cmd ="/usr/bin/java javaprog";
system($cmd);

the java prog returns an error code if there is an error when the java prog runs
how can i catch the return code of the java prog reliably ?

There are several ways (read "perldoc -f system" to find out what
some of them are). One of the simplest ways is to check the $?
variable, like this:

my $cmd ="/usr/bin/java javaprog";
system($cmd);
my $errorCode = $? >> 8; # don't forget the ">> 8" part!
print "The error-code from the command was $errorCode.\n";

Hope this helps. You might also want to read the "perldoc perlvar"
documentation and search for the "$?" variable for more advice.

-- J.