redirect function to /dev/null

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

if i call system(test.pl)>/dev/null from perl it redirects all execution of test.pl to null device.
is ther any way to redirect function call execuiton. what i mean is if i call
&func(), is it possible to redirect its execution to /dev/null. i dont want to ue system thats why i am in need of it .

Comment on redirect function to /dev/null

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Re: redirect function to /dev/null by ikegami (Patriarch) on Mar 03, 2006 at 05:58 UTC
`{ # Temporarily undefine STDOUT. local STDOUT; func(); }` [download] as in `sub func { print("in func\n"); } print("pre func\n"); { # Temporarily undefine STDOUT. local STDOUT; func(); } print("post func\n");` [download] If `func` checks the return value of `print` in the above, it will notice that `print` failed. If you really wanted to print to `/dev/nul` (or to another file) and avoid that (rare) problem, you'd use `{ # Temporarily redirect STDOUT. open(local *STDOUT, '>', '/dev/nul'); func(); }` [download] You can do the same with `STDERR`. You might also want to look at `$SIG{__WARN__}`.	[reply] [d/l] [select]

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Re: redirect function to /dev/null
by ikegami (Patriarch) on Mar 03, 2006 at 05:58 UTC

{
   # Temporarily undefine STDOUT.
   local *STDOUT;
   func();
}
[download]

sub func { print("in func\n"); }

print("pre func\n");
{
   # Temporarily undefine STDOUT.
   local *STDOUT;
   func();
}
print("post func\n");
[download]

If func checks the return value of print in the above, it will notice that print failed. If you really wanted to print to /dev/nul (or to another file) and avoid that (rare) problem, you'd use

{
   # Temporarily redirect STDOUT.
   open(local *STDOUT, '>', '/dev/nul');
   func();
}
[download]

You can do the same with STDERR. You might also want to look at $SIG{__WARN__}.

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