I've needed to incorporate a detection of a piped input to my program. Searched the documentation and forums and found and placed the following to my code: 
my $rin = "";
vec($rin, fileno(STDIN), 1) = 1;
my $isPiped = select($rout=$rin,"","",1);

if($isPiped){
 #Do the data processing from pipe
}

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I tryed to understand the code, but not really. It works though, when I do: 
some-program|myprogram -parameters

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But, aftera a while, I stumbled on a problem, that on certain cases, it doesn't detect that there is an input, coming from pipe. Maybe, when the system was buisy and the data from pipe was taking a while to come, so, after trials and errors, I came up with the solution: 
my $rin = "";
sleep(5);
vec($rin, fileno(STDIN), 1) = 1;
sleep(5);
my $isPiped = select($rout=$rin,"","",1);

if($isPiped){
 #Do the data processing from pipe
}

[download]
And it works every time, but now it waits for at least a 10 seconds every time. It becomes pretty annoying, after a while. Is there a better, more efficient solution to data coming through a pipe detection?

In reply to Detect piped input by igoryonya

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