I use this regex https://regex101.com/r/7Cw1fy/1

abc(\s*)(?![\S] )

abc matches -> OK

abc cde matches -> not OK

CodePudding user response：

You can use

abc(?!\s*\S)(\s*)

See the regex demo. Details:

• abc - a fixed string
• (?!\s*\S) - a negative lookahead that fails the match if there are zero or more whitespaces followed with a whitespace immediately to the right of the current location
• (\s*) - Group 1: zero or more whitespaces.

CodePudding user response：

Why not use: abc\s*$ ?

This will match only if there are no character other than a whitespace following 'abc'.

Test here: https://regex101.com/r/HdJ0FS/1

abc             -> matches
abc cde         -> no match
abc             -> match
abc      sdfds  -> no match