$re = '/(TDT\+20\+LA8031\+\+\+LA)/';
$str = 'UNA:+.? \' UNB+UNOA:4+TAM:JJ+APIAR:ZZ+170911:1456+1709111456++APIS\' UNG+PAXLST+TAM:JJ+APIAR:ZZ+170911:1456+1709111456+UN+D:02B\' UNH+CRW001+PAXLST:D:02B:UN:IATA\' BGM+250+DC:1.0\' TDT+20+LA8031+++LA\' LOC+125+GRU\' DTM+189:1709091315:201\' LOC+87+AEP\' DTM+232:1709091610:201\' NAD+FM+++RAVAZZOLLI ABUD SILVA:MARCELO+454 AGOSTINHO DE FARIA+SAO PAULO+SP+0828 0 100+BRA\' ATT+2++M\' DTM+329:680426\' NAT+2+BRA\' DOC+P:110:109+F0722522\' DTM+36:251102\' LOC+91+BRA\' NAD+FM+++BOCK PEREIRA:RICARDO+209 NHU GUACU AP 104+SAO PAULO+SP+04625001+BRA\' ATT+2++M\' DTM+329:800513\' NAT+2+BRA\' DOC+P:110:109+FR676533\' DTM+36:261003\' LOC+91+BRA\' NAD+FM+++BARBOSA DA SILVA:THIAGO+RUA PELOTAS 323 AP 143+SAO PAULO+SP+04012 903 +BRA\'';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php