Why am I getting error print() on closed filehandle in Perl - perl

Question

I am trying to write output to one C file but I'm getting an error about print() on closed filehandle.
my $fileoutput="output.c";
open OUTFILE, "> $fileoutput" or die $!;
for my $i (keys%hash) {
# grep for c file output and compare
# with xml key print both key and values
if (grep $_ eq $i,#c_result_array) {
if (defined $hash{$i}) {
my #values = $hash{$i};
print OUTFILE $i . "=> #values";
print OUTFILE "\n";
}
close OUTFILE;
}
}

Answer 1

You close the output file inside the for loop. By the second iteration, the file handle has been closed. You have to close the file once the loop has run to completion.
Also, bareword file handles have package scope which comes with all the disadvantages of global variables. Use lexical file handles.
Also, especially if the name of the file you are opening is coming from the outside, use the three argument form of open, and always include the name of the file in error messages.
Finally, presumably, $hash{$i} contains an array reference, so you have to dereference it if you are going to interpolate its contents into a string.
my $fileoutput = "output.c";
open my $OUTFILE, '>', $fileoutput
or die "Failed to open '$fileoutput': $!";
for my $i (keys %hash) {
#grep for c file output and compare with xml key print both key and values #
if (grep $_ eq $i, #c_result_array) {
if(defined $hash{$i}) {
my #values = #{ $hash{$i} };
print $OUTFILE "$i => #values\n";
}
}
}
close $OUTFILE
or die "Failed to close '$fileoutput': $!";