What's the difference between egrep and grep - simple high level explanation

Question

What's the difference between egrep and grep ?

I've been search for a while online and can't find anything concise.

Are they the same except that egrep has some extended regexp features? Thanks

See also Why does my regular expression work in X but not in Y? for a brief description of the differences between basic regular expressions (BRE, grep) and extended regular expressions (ERE, grep -E/egrep) — ilkkachu, Aug 10 '21 at 21:01

score 0 · Answer 1 · answered Aug 10 '21 at 20:55

On my RHEL 8 system:

$ ls -la /usr/bin/egrep
-rwxr-xr-x. 1 root root 28 Aug 12  2018 /usr/bin/egrep
$ file /usr/bin/egrep
/usr/bin/egrep: POSIX shell script, ASCII text executable
$ cat /usr/bin/egrep
#!/bin/sh  
exec grep -E "$@"

So, yes - egrep is simply a wrapper around grep that turns on the extended regexp features.

score 0 · Answer 2 · answered Aug 10 '21 at 20:55

Extract from man page on Debian Gnu/Linux

       ... the variant programs egrep, fgrep and rgrep are the same
       as grep -E, grep -F, and grep -r,  respectively.   These  variants  are
       deprecated, but are provided for backward compatibility.

What's the difference between egrep and grep - simple high level explanation

2 Answers2