pipes problem

From: Billy N. Patton (b-patton_at_ti.com)
Date: 09/28/04 

Date: Tue, 28 Sep 2004 14:51:25 -0500

I have this bit of code:

The followfing sets $stat correctly : to 0
   my $stat = 0;
   $ret = undef;
   $ret = `$command`;
   $stat = $? >> 8;

The follow sets $stat to 1, Incorrect.
# open PIPE , "$command 2>&1 |";
# while (<PIPE>)
# {
# Lis($_);
# $ret .= $_;
# }
# $stat = close PIPE;

in book "Programming Perl" @nd Edition , Covers perl5
Page 342. Last 5 lines
the exit sataus of the child process is haaarvested by the parent
process when it eventually doeas a wait(2) system call. But this
happens in the close function, not in the open function. And that's why
you have to check the return vallue of your close function.

I tried this and got the proper return code:
   close PIPE;
   $stat = $? >> 8;

Even this worked:
   close PIPE;
   $stat = $?;

I don't understand?????

My goal here is to execute a system command and be able to capture the
stdout/stderr as it is happening. I don't like programs that simply sit
and give you no indication anything is happening. 

-- 
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            /___/
Texas Instruments ASIC Circuit Design Methodlogy Group
Dallas, Texas, 214-480-4455,  b-patton@ti.com

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