Re: 'exec' & 'Location' problem

exec will never exit, this is the expected behaviour. There are many ways to execute external programs in perl.

Example 1:

#!/usr/bin/perl -w
if (condition) {
   system '/usr/.../another.pl';
}
print "Location: http://test/ \n\n";
[download]

Example 2:

#!/usr/bin/perl -w
if (condition)
{
  `/usr/.../another.pl`
  # notice the use of the back quote.
}
print "Location: http://test/ \n\n";
[download]

There are other methods too, like using Apache mod_perl's spawn_sub_process, etc.

Comment on Re: 'exec' & 'Location' problem Select or Download Code

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Re: 'exec' & 'Location' problem by Abigail-II (Bishop) on Sep 12, 2003 at 10:37 UTC
exec will never exit That's not quite true. The manual page says: `exec PROGRAM LIST The "exec" function executes a system command and never returns-- use "system" instead of "exec" if you want it to return. It fails and returns false only if the command does not exist and it is exe- cuted directly instead of via your system's com- mand shell (see below).` [download] It can fail, but that's an exception. Abigail	[reply] [d/l]
Re: Re: 'exec' & 'Location' problem by Roger (Parson) on Sep 12, 2003 at 13:12 UTC
Thanks Abi for pointing out that exec will return false upon error. I assumed too much and overlooked the fact that the external program might not exist.	[reply]
Re: Re: 'exec' & 'Location' problem by hmerrill (Friar) on Sep 12, 2003 at 12:44 UTC
Be sure to read the perldocs on the 'system' and backticks commands: `perldoc -q backticks perldoc -q system perldoc -f system` [download] so that you're aware of all the implications - security and otherwise. If you use 'system', be aware that system does give back a return code, and, there is a 'more right' way to execute 'system' (and backticks) so that the shell is not involved. HTH.	[reply] [d/l]