use warnings; use strict; my $content = '{ "geometry": { "type": "Polygon", "coordinates": [ [ [ 19.054804912278406, 47.485785556135411 ], [ 19.057857836771483, 47.487322542030711 ], [ 19.06025597925397, 47.488491565765209 ], [ 19.060347248086835, 47.488539642204628 ], [ 19.060463310421543, 47.484578287406251 ], [ 19.054804912278406, 47.485785556135411 ] ] ] } }'; $content =~ s/(\d\d\.\d*)/substr($1,0,9)/ge; print "$content\n"; __END__ { "geometry": { "type": "Polygon", "coordinates": [ [ [ 19.054804, 47.485785 ], [ 19.057857, 47.487322 ], [ 19.060255, 47.488491 ], [ 19.060347, 47.488539 ], [ 19.060463, 47.484578 ], [ 19.054804, 47.485785 ] ] ] } }