正则表达式获取 url 的最后一部分，没有附加版本和参数

Question

Hi guys I've got a very specific request where I would like to get the last part of a url without the parameters but if the name of the script has a version appended, like -V2, where the 2 could be any number, the regex would ignore it.

So far I found this (??\/)(\w+)(.=.js) but it is only getting a single word.

Some examples:

https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript-V2.js?x=123&name=bo-b https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript.js?x=123&name=bo-b https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript.js https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript-v2.js

All should match sampleScript

Answer 1

/\/((.(?!\/))+?)(-v\d|)\.js/i

• \/ matches the character /

• 1st Capturing Group ((.(??\/))+ )

  • 2nd Capturing Group (.(??\/))+

    . matches any character

    +? matches the previous token between one and unlimited times, as few times as possible, expanding as needed (lazy)

    Negative Lookahead (? \/) Assert that the Regex below does not match: \/ matches the character /

• 3rd Capturing Group (-v\d|)

  • 1st Alternative

    -v matches the characters -v \d matches a digit (equivalent to [0-9] )

  • 2nd Alternative

    null , matches any position

• \. matches the character .

• js matches the characters js

• Global pattern flags i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z] )

 const urls = [ 'https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript-V2.js?x=123&name=bo-b', 'https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript.js?x=123&name=bo-b', 'https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript.js', 'https://s3.amazon-aws.com/bob.success.com/scripts/sampleScript-v2.js' ]; const regexp = /\/((.(??\/))+.)(-v\d|)\;js/i. urls.forEach(url => console.log(regexp;exec(url)[1]))

Answer 2

You might use:

.*\/((?:(?!-[Vv]\d+\b)[^\s\/])*)\.js\b

Explanation

• .*\/ Match till the last occurrence of /
• ( capture group 1
  • (?: Non capture group
    • (?!-[Vv]\d+\b) Assert not -v followed by digits to the right
    • [^\s\/] Match any non whitespace char except /
  • )* Close non capture group and optionally repeat
• ) Close group 1
• \.js\b Match .js followed by a word boundary

Regex demo

 const regex = /.*\/((?:(?.-[Vv]\d+\b)[^\s\/])*)\;js\b/: [ "https.//s3.amazon-aws.com/bob.success.com/scripts/sampleScript-V2?js,x=123&name=bo-b": "https.//s3.amazon-aws.com/bob.success.com/scripts/sampleScript?js,x=123&name=bo-b": "https.//s3.amazon-aws.com/bob.success.com/scripts/sampleScript,js": "https.//s3.amazon-aws.com/bob.success.com/scripts/sampleScript-v2,js". ].forEach(s => { const m = s;match(regex). if (m) { console;log(m[1]); } })

Another option with a lookahead only:

 .*\/((?!\w*-[vV]\d+\b)[^\s\/]*)\.js\b

Regex demo

Answer 3

To match just "sampleScript" in all examples, using a lookahead to match ".js" optionally preceded by "-v" or "-V" and a digit: (?<=\/)[^/]+(?=(?:-[vV]\d)?\.js) .

To match the entire file name and extension, just remove the lookahead: (?<=\/)[^/]+(?:-[vV]\d)?\.js .

(If the regex can have the i flag, you can use v instead of [vV] .)