Hi, LanX has given you the reason why your code failed. You might have found out by yourself with more ease if you had used a more meaningful error message. Instead of: 
chdir($corner) or die "\n $!\n";

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You may want something like this: 
chdir($corner) or die "\nCannot cd to $corner $!";

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giving you more useful information on what failed. BTW, it is better not to put "\n" after $!, because you get more information if you don't. Consider these two one-liners: 
$  perl -e 'my $c = "foobar.txt"; open my $FH, "<", $c or die "cannot 
+open $c $!"; '
cannot open foobar.txt No such file or directory at -e line 1.

$  perl -e 'my $c = "foobar.txt"; open my $FH, "<", $c or die "cannot 
+open $c $!\n"; '
cannot open foobar.txt No such file or directory

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As you can see, without the "\n", you get the code line number where the exception occurred (of course, this is not very useful in a one-liner, but quite practical with larger programs).

A small additional point is that the: 

&loading_tsc;

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syntax for calling a function has been superseded about 20 years ago and was replaced with: 
loading_tsc();
# or: loading_tsc($param1, $param2);

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The syntax with & may still be used, but only to obtain some special effects on the function call (by-passing prototypes). You are not using prototypes here (and they would not be very useful), so rather use the regular syntax with parens.

In reply to Re: calling subroutine inside loop - ERROR - subroutine executes only once by Laurent_R
in thread calling subroutine inside loop - ERROR - subroutine executes only once by kaushik9918

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