Regular expression syntax to match first segment only

Question

I have number of URLs where I need to match first segment without "/" with Regex

This segment can be either xx or xx-xx.

I've tried to do it with lookahead and lookbehind but sometimes in the URL I have another 2 letter segment. (/ts/; /ca/) I don't want /ts; /ca/ them to match. I only want first segment in my Regex. Any suggestions? Thanks.

https://regex101.com/r/Qy3nyI/1

(?<=\/)\w{2}(-\w{2})?(?=\/)

Test urls:

/en/home.aspx
/en-gb/ts/tc/home.aspx
/en-gb/home.aspx
/en-de/home.aspx
/de-de/home.aspx
/en/home.aspx
/en-fb/afspfas.aspx
/en-gb/ts/ca/anotherPage.aspx

Answer 1

Try adding a starting ^ anchor to the initial lookbehind in your current regex pattern:

(?<=^/)\w{2}(-\w{2})?(?=/)
    ^^ change is here

Updated demo:

Demo

This pattern says to:

(?<=^/)         lookbehind and assert that what precedes is a leading /
\w{2}(-\w{2})?  then match the country abbreviation text
(?=/)           lookahead and assert that what follows is another /