$re = '/([^\/]+\.vcf\.gz)/m';
$str = '##bcftools_mergeCommand=merge --force-samples -m none -O v -o analysis/STUDY1/hg19/exome/merged.vcf --threads 4 analysis/STUDY1/hg19/exome/varscan_norm.vcf.gz analysis/STUDY1/hg19/exome/gatk_norm.vcf.gz analysis/STUDY1/hg19/exome/samtools_norm.vcf.gz analysis/STUDY1/hg19/exome/freebayes_norm.vcf.gz';
preg_match_all($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