The biggest change? “It’s now made more clear that if you are still relying on the egrep and fgrep commands, it’s past due for switching to just grep with the appropriate command-line arguments.”
The egrep and fgrep commands have been deprecated since 2007. Beginning with GNU Grep 3.8 today, calling these commands will now issue a warning to the user that instead they should use grep -E and grep -F, respectively.
Eventually, GNU Grep will drop the egrep / fgrep commands completely but there doesn’t seem to be a firm deadline yet for when that removal will happen.
From grep’s updated manual:
7th Edition Unix had commands egrep and fgrep that were the counterparts of the modern ‘grep -E’ and ‘grep -F’. Although breaking up grep into three programs was perhaps useful on the small computers of the 1970s, egrep and fgrep were not standardized by POSIX and are no longer needed. In the current GNU implementation, egrep and fgrep issue a warning and then act like their modern counterparts; eventually, they are planned to be removed entirely.
If you prefer the old names, you can use use your own substitutes, such as a shell script…
Other notable changes from the release announcement:
The confusing GREP_COLOR environment variable is now obsolescent. Instead of GREP_COLOR=’xxx’ use GREP_COLORS=’mt=xxx’
Regular expressions with stray backslashes now cause warnings
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