Once in a while I come across some topic that I should have learned a billion years ago. Something very basic and useful that I had a chance of seeing many times but haven’t, or probably had and ignored it. Today I found out that I was missing an important bit of Perl regexp knowledge. And you will probably laugh in my face when I’ll tell you.<\/p>\n
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Regular expression matching returns values as any other Perl function. The return value depends on the context. In scalar context, the value of 1 (true) is returned if there was a match. But the array context is more interesting. Actual matches are returned and can be used like so:<\/p>\n What was I doing until now? Well, I was simply copying the data string into a temporary variable, and than removing everything that I didn’t need from that string. Obviously, that was one ugly and complex way of doing things. I wonder how did I went so far without finding it out.<\/p>\n\n","protected":false},"excerpt":{"rendered":"\n Once in a while I come across some topic that I should have learned a billion years ago. Something very basic and useful that I had a chance of seeing many times but haven’t, or probably had and ignored it. Today I found out that I was missing an important bit of Perl regexp knowledge. … Continue reading Missing some regexp knowledge<\/span><\/a><\/p>\n\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false,"_links_to":"","_links_to_target":""},"categories":[1,18],"tags":[36],"keyring_services":[],"class_list":["post-9613","post","type-post","status-publish","format-standard","hentry","category-general","category-programming","tag-perl"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\tundef<\/code> is returned if there was no match. Here is an example:<\/p>\n\r\n#!\/usr\/bin\/perl -w\r\nuse strict;\r\n\r\nmy $line = 'this is my line';\r\nmy $result = $line =~ \/is\/;\r\nprint $result, \"\\n\";\r\n<\/pre>\n
\r\n#!\/usr\/bin\/perl -w\r\nuse strict;\r\n\r\nmy $line = 'this is my 123 line with 456 numbers';\r\nmy @result = $line =~ \/.*?(\\d+).*?(\\d+).*\/g;\r\nprint join(\"\\n\",@result), \"\\n\";\r\n<\/pre>\n