[mcmire]

Not true. Regexes have been around for a long time and there are a few standards -- POSIX basic, POSIX extended, and PCRE. Any language/tool worth its salt these days will follow one of these three implementations (usually it's PCRE as it's the most complete). It's usually older tools like awk, vim, find, etc. that have their own quirks -- they were created before these standards existed and so they generally follow extended regex but then introduce their own syntax for certain concepts (in vim, for instance, \<...\> does the same thing as \b...\b in PCRE).

[hnriot]

Didn't you just make the previous commenters point, that regex implementations vary? Within those three there are variations too with the flags and how they implement word boundaries (either exclusion of word characters or inclusion of certain spacing chars)

[jessedhillon]

I think the case that there are too many implementations is overstated. Almost everyone can get away with knowing only PCRE these days. Most programmers I've know don't even know that they're using PCRE, they just know they're using "regexes"

[saraid216]

I haven't had the incentive to learn regexes well enough to understand why I have to escape random things in different languages and environments. And occasionally something will fail to work all my cases and I have to fall back on a non-regex way of matching.

I've generally found that my practice is basically "try regex; if it doesn't work after ten minutes of effort, abandon regex completely".