[behnamoh]

rather egrep, though

[benji-york]

Both grep and egrep are the same executable.

  bash-3.2$ diff `which grep` `which egrep`
  bash-3.2$

[sizzzzlerz]

Can egrep do lookaheads or behinds? I find it necessary to use positive lookaheads to verify the test words include all the letters marked present but in the wrong location.

[lancebeet]

I was also curious about this as I use grep -P (for PCRE regexes) if I need to use them. Looking at the manual, lookaheads and lookbehinds don't seem to be supported by regular gnu grep or grep -E, so you do need to use grep -P for them.

https://www.gnu.org/software/grep/manual/grep.pdf

[_moof]

egrep is grep -E.