use strict; use warnings; my $char_bit; open my $fh, "<", "/usr/include/limits.h"; while (<$fh>) { ($char_bit = $1, last) if /^#\s*define\s*CHAR_BIT\s*([0-9]+)/; } print "$char_bit\n"; #### use strict; use warnings; use Config; print "$Config{charbits}\n";