grep command in linux using " in regex - Stack Overflow
Mar 22, 2018 · The two options are: with -E, grep uses extended regular expressions, in which {} are automatically range operators. without -E, you need to use backslashes to mark the {} as range …
regex - Using the star sign in grep - Stack Overflow
Jul 6, 2016 · grep * means "0 or more", and grep is greedy by default. Note that in grep basic regular expressions the metacharacters ?, + , { , | , ( , and ) lose their special meaning.
grep a tab in UNIX - Stack Overflow
In regex language the tab symbol is usually encoded by \t atom. The atom is supported by BSD extended regular expressions (egrep, grep -E on BSD compatible system), as well as Perl …
bash - Capturing Groups From a Grep RegEx - Stack Overflow
The first capture group is stored in index 1, the second (if any) in index 2, etc. Index zero is the full match. side note #1 regarding regex anchors: You should be aware that without anchors, this regex …
Regex (grep) for multi-line search needed - Stack Overflow
Sep 15, 2010 · Regex (grep) for multi-line search needed [duplicate] Asked 15 years, 3 months ago Modified 2 years, 2 months ago Viewed 317k times
regex - How to find patterns across multiple lines using grep? - Stack ...
Apr 22, 2010 · If the -z options specifies grep to treat newlines as zero byte characters then why do we need the (?s) in the regex ? If it is already a non-newline character, shouldn't . be able to match it …
bash - Piping to grep and using regex - Stack Overflow
Piping to grep and using regex Asked 12 years, 10 months ago Modified 9 years, 5 months ago Viewed 33k times
Grep 'OR' regex problem - Unix & Linux Stack Exchange
I am trying to use grep with a regex to find lines in a file that match 1 of 2 possible strings. Here is my grep: $ grep "^ID.*(ETS|FBS)" my_file.txt The above grep returns no results. However if I
Can grep output only specified groupings that match?
GNU grep has the -P option for perl-style regexes, and the -o option to print only what matches the pattern. These can be combined using look-around assertions (described under Extended Patterns …
Correct regex not working in grep - Unix & Linux Stack Exchange
Feb 11, 2019 · grep does POSIX regular expressions. These are basic regular expressions (BRE) and extended regular expressions (ERE, if grep is used with the -E option). See the manual for re_format …