Rob Dixon wrote:
John W. Krahn wrote:
pa...@compugenic.com wrote:
I want to extract a list of postfix's queue id's. The 'mailq' command
returns output as follows:
right now I'm doing the following:
my @ids;
foreach (`mailq`) {
next unless /^\w+/;
chomp;
push @ids, (split)[0];
}
I know it can be done with one line. Here's what I've got so far:
my @ids = map {chomp; (split)[0] if /^\w/} `mailq`;
You don't need chomp() because split() removes *all* whitespace, and
besides you are only using the first field.
This 'kinda' works, but it also adds a bunch of blank elements to the
@ids array. What am I doing wrong?
my @ids = map /^\w/ ? (split)[0] : (), `mailq`;
my @ids = map /^(\w+)/, `mailq`;
Not the same thing. Possibly:
my @ids = map /^(\S+)/, `mailq`;
Or:
my @ids = map /^(\w\S*)/, `mailq`;
Or:
my @ids = `mailq` =~ /^\w\S*/mg;
John
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