What regular expression can I use to extract the value of a query-string parameter?

Question

This is my string: href="/store/apps/details?id=SomeString&.

How can I extract the SomeString with PerlRegEx? I'm using Delphi XE2.

@Kermia: it matters a lot, since regex flavors vary from a language to the next. — Denis de Bernardy, Jun 17 '13 at 15:21
@DavidHeffernan Is it available in XE2? I didn't know that:) — Kermia, Jun 17 '13 at 15:30
Was introduced in XE. I think it's just a wrapping up of the library you are using. — David Heffernan, Jun 17 '13 at 15:33
Wouldn't it be better to use a dedicated library routine rather than regex? — David Heffernan, Jun 17 '13 at 21:22
Have you read this: http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags — David Heffernan, Jun 18 '13 at 06:19

ctn · Accepted Answer · 2013-06-17T15:36:21.627

4

You can use the following:

href="/store/apps/details\?id=([^&"]*)

SomeString will be captured in group 1.

edited Jun 17 '13 at 15:36

answered Jun 17 '13 at 15:21

ctn

You're missing something: ` this gets captured too.` – Denis de Bernardy Jun 17 '13 at 15:23
@ctn It doesn't work. The String `href="/store/apps/details?id=` is a constant. and must exist in the string – Kermia Jun 17 '13 at 15:35

score 2 · Answer 2 · answered Jun 17 '13 at 15:32

2

use the regex: \bid=.*(&)?

answered Jun 17 '13 at 15:32

Rayhan.iit.du

score 1 · Answer 3 · answered Jun 17 '13 at 15:23

1

You can use the following regex

[?&]id=([^a]*)&?

mind you depending on what is and is not an allowable input, just about any conceivable reg-ex can be tricked

answered Jun 17 '13 at 15:23

score 1 · Answer 4 · answered Jun 17 '13 at 15:23

1

You can use : .*id=\([^&]*\)&

Depending on the language you are using, you might find tools cleaner than regexps to perform this task.

answered Jun 17 '13 at 15:23

SylvainD

4 Answers4