reading all process numbers into an array

[dn_perl]

From command line, the following command gives IDs of all the
processes.
ps -ef | awk -F" " '{print $2}'

But if I use the command in a perl script within backticks, I get full
listing in the array instead of just the process IDs.

my @list_of_procs ;
@list_of_procs = ` ps -ef | awk -F" " '{print $2}' ` ;

Why is this so and how do I create an array with just the process IDs?


Thanks in advance.

 

[Ben Morrow]

Quoth (e-mail address removed) ([email protected]):

From command line, the following command gives IDs of all the
processes.
ps -ef | awk -F" " '{print $2}'

But if I use the command in a perl script within backticks, I get full
listing in the array instead of just the process IDs.

my @list_of_procs ;
@list_of_procs = ` ps -ef | awk -F" " '{print $2}' ` ;

Why is this so and how do I create an array with just the process IDs?

Use Proc:rocessTable instead, or at least do the split in perl:

my @list_of_procs = map { (split)[1] } `ps -ef`;

The reason the awk fails is because `` do double-quotey interpolation,
so you need

@list_of_procs = `ps -ef | awk -F" " '{print \$2}'`;

or

my $cmd = q/ps -ef | awk -F" " '{print $2}'/;
my @list_of_procs = qx/$cmd/;

Ben

 

[Gregory Toomey]

From command line, the following command gives IDs of all the
processes.
ps -ef | awk -F" " '{print $2}'

But if I use the command in a perl script within backticks, I get full
listing in the array instead of just the process IDs.

my @list_of_procs ;
@list_of_procs = ` ps -ef | awk -F" " '{print $2}' ` ;

Why is this so and how do I create an array with just the process IDs?


Thanks in advance.

You probably want (under linux)

for (split '\n', qx(ps -o pid --no-headers)) {
...
}

gtoomey