Thanks, I did not realize that (caller) is a function call and [1,2] was a slicing operation.
Thanks for the info. Regards, Manish
On 04/25/2005 08:49 PM, Jay Savage wrote:
On 4/25/05, Manish Sapariya <[EMAIL PROTECTED]> wrote:
Hello, Can somebody explain me the magic here....
sub vprint (@) { # subroutine declaration with prototype
return unless $Utils::verbose; # exit sub unless $Utils::verbose flag is set
my ($file, $line) = (caller)[1,2];
# take a slice (the second and third items: the file containing
# the package where the subroutine was called, and the line
# number where it was callled) of the list returned by the # caller() function, and assign the values to $file and $line. # see perldoc -f caller for details.
my $subr = (caller 1)[3] || 'main';
# take a slice of (only the thrid item) of the list returned
# by caller(1) and assign the value (the subroutine name
# of the subroutine where the current subroutine (vprint)
# was invoked to $subr. (caller 1)[3] is undefined, use # 'main' instead. see perldoc -f caller for details.
$file =~ s!.*/!!; # strip everything up to the last '/' character from $file # in case (caller)[1] is a full path name.
print STDERR "$subr($file:$line): ", @_;
# print the subroutine, file, and line number information, # along with anything else passed to the sub on STDERR.
}
HTH,
--jay
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