grep -e PATTERN unless, as stated in an earlier Answer and in the man pages, there are multiple search patterns, or to protect a pattern beginning with a hyphen (-).

May 16, 2019 · Moreover, this is a lot faster than a regular grep invocation, since it can exit immediately when the first match is found, rather than needing to unconditionally read (and write) to the end of file.

Jun 16, 2013 · As you mentioned, grep -E is for extended regular expressions whereas -e is for basic regular expressions. From the man page: EDIT: As Jonathan pointed out below, grep -e "specifies …

Feb 16, 2016 · grep -r "texthere" . The first parameter represents the regular expression to search for, while the second one represents the directory that should be searched. In this case, . means the …

Apr 5, 2015 · 11 grep when used with ps -ef also outputs the grep used for filtering the output of ps -ef. grep -v grep means that do not include the grep used for filtering in the command output. You can …

Dec 17, 2014 · To expand on @gilles answer to make it a little more informative, especially if the list of files you're dealing with is large, you can report the file name (relative path) of each file along with the …

Mar 31, 2014 · In the man page: -r Read all files under each directory, recursively, following symbolic links only if they are on the command line. what exactly does "being on the command line" means? T...

Jul 6, 2016 · grep itself doesn't support wildcards on most platforms. You have to use egrep to use wildcards. Shells have a different syntax. "*" in the shell is <any string>. In egrep it's an operator that …

Mar 25, 2016 · I would like to get the multi pattern match with implicit AND between patterns, i.e. equivalent to running several greps in a sequence: grep pattern1 | grep pattern2 | ... So how to …

Sep 20, 2015 · Is there a way to perform a grep based on the results of a previous grep, rather than just piping multiple greps into each other. For example, say I have the log file output below: ID 1000 xyz …