Thanks, just learned something new. grep predates GNU by about a decade it seems.
a more accurate term would be "BRE with GNU extensions", e.g. \(\)
\(\) are part of BRE syntax. They are not GNU extensions.
Source: http://pubs.opengroup.org/onlinepubs/7908799/xbd/re.html#tag...
er, I meant \{\}.
\{n\}, \{n,\} and \{n,m\} are all in POSIX.
\{,m\} is a (pretty obscure) GNU extensions.
hm, I could've sworn it wasn't. http://www.regular-expressions.info/gnu.html says that \?, \+, and \| are GNU extensions though.
from the qed/ed editor idiom g/re/p, where re stands for a regular expression, to Globally search for the Regular Expression and Print the lines containing matches to it
In fact, grep predates the GNU project by almost a decade.
Also, it's the first time I hear about "GNU" regexps.