Regex - exclude word within string

Question

I want to match everything except “eps1@“ within this string:

HelpMe_pleas3_eps1@

I tried [^eps1@] but this matched everything except every instance of “e” “p” “s” “1” “@“. I just want “eps1@“ excluded.

Answer 1

There are many ways of doing it, depending on what you really need.

Using (.*)eps1@ you match everything before "eps1@" in the first capturing group. See demo #1.

Using (.*)eps1@(.*) you match everything before and after "eps1@" in the first and second capturing groups. See demo #2.

If "eps1@" occurs multiple times, you can use this regex:

(?:[^eps1@]|e(?!ps1@)|(?<!e)p(?!s1@)|(?<!ep)s(?!1@)|(?<!eps)1(?!@)|(?<!eps1)@)+

That means:

• [^eps1@] any character but "e", "p", "s", "1", and "@"; OR
• e(?!ps1@) the character "e" if not followed by "ps1@"; OR
• (?<!e)p(?!s1@) the character "p" if not preceded by "e" and not followed by "s1@"; OR
• and so forth.

See demo #3.

But have you considered just replacing "eps1@" with "" into your source string?

P.S. For the next questions I'd suggest you to be more precise on the language you're using.