In GNU grep
, the regular expression [\d]
matches the character class d
only, because it does not have any special meaning in POSIX regular expressions.
However, when PCRE (Perl-Compatible Regular Expressions) is enabled, the backslash (\
) is interpreted as an escape character for special characters, and the character class \d
is recognized as shorthand for "digit character".
Therefore, in PCRE-enabled GNU grep
, the correct syntax for matching digit characters would be \d
or [[:digit:]]
.
Asked: 2023-02-26 11:00:00 +0000
Seen: 8 times
Last updated: Dec 16 '21