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Capturing STDERR with backtics

Posted by enquirer (enquirer), 30 May 2003
If i try:

     $ls = `ls -l`

Then the output of the ls command that would usually go to STDOUT gets captured in $ls instead - all good.

However, I need a way of catching STDERROR.

For example, if I try:

     $mysql = `mysql ... blah blah some set of args`

And it fails for some reason, then I need the perl script to be able to react to that. The error from the mysql client gets written to STDERR and appears on the screen, while $mysql is empty...



Posted by admin (Graham Ellis), 30 May 2003
First thought ... use shell redirection within the backtics:

Code:
#!/usr/bin/perl

$what = `mysql -hlocalhost -ufred -pgubbins`;
print "I got back .... $what \n";

$wow = `mysql -hlocalhost -ufred -pgubbins 2>&1`;
print "I got back .... ",lc($wow),"\n";


When run, I got:

Code:
[localhost:~] graham% perl djk
ERROR 1045: Access denied for user: 'fred@localhost' (Using password: YES)
I got back ....
I got back .... error 1045: access denied for user: 'fred@localhost' (using password: yes)

[localhost:~] graham%


(the messing about with the lc function was just to prove that the results were in the $wow variable).



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