comment on

There are two ways of doing this that I can think of:

Use system, and add an ampersand at the end, like this:
```
system("command &");
[download]
```
system uses a shell to execute the command, so it will correctly recognize the ampersand and put the code in the background. The disadvantages of this approach are that an extra process (the shell) gets executed, and that shell meta-character interpretation is done (this could also be considered an advantage, but it opens potential security concerns). The advantage is that it's easy to do.
Use fork and exec, something like this:
```
my $pid;
if (defined ($pid=fork)) {
  if (!$pid) {
    # Execute command in the child
    exec ("command");
    # If it returns, there was an error
    die "Error executing command: $!\n";
  }
  # The parent continues unaffected, falls of the if stmt
}
else {
  die "Error in fork: $!\n";
}
[download]
```
This has the advantages that it is more efficient (just your two processes are started) and that no shell metacharacters are interpreted (again, this could be a disadvantage depending on what you need). The slight disadvantage is that it's more complex to code.
--ZZamboni

In reply to Re: Don't want to wait by ZZamboni
in thread Don't want to wait by Charlie

Title:
Use: <p> text here (a paragraph) </p>
and: <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

For: Use:

& &

< <

> >

[ [

] ]
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.

	For:		Use:
	&		`&`
	<		`<`
	>		`>`
	[		`[`
	]		`]`