use warnings; use strict; use POSIX qw/LC_NUMERIC/; use FFI::Platypus 1.07; my $ffi = FFI::Platypus->new( api => 1 ); $ffi->lib(undef); # search current process for symbols (libc etc.) my $loc = $ffi->function( setlocale => ['int','string'] => 'string' ) ->call(LC_NUMERIC, ""); # set according to environment vars print "Locale: $loc\n"; $ffi->attach( [ printf => 'cprintf_i' ] => ['string'] => ['int'] => 'int' ); # variadic function cprintf_i("%'d\n", 42e6); # ##### UPDATE - Wrapped in a sub ##### $ffi->attach( [ snprintf => 'c_snprintf_i' ] => ['opaque','size_t','string'] => ['int'] => 'int' ); sub commify { my $i = shift; die "Bad integer $i" unless $i=~/\A-?[0-9]+\z/; my $in = "$i$i"; my $ptr = $ffi->cast('string' => 'opaque', $in); c_snprintf_i($ptr, length($in), "%'d", 0+$i); my $out = $ffi->cast('opaque' => 'string', $ptr); return $out; } print commify(42e6), "\n";