What is the difference between grep -e and grep -E option?
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 (-).
linux - What is the point of "grep -q" - Stack Overflow
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.
UNIX grep command (grep -v grep) - Stack Overflow
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 …
How to run grep with multiple AND patterns? - Unix & Linux Stack …
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 …
What's the difference between grep -r and -R - Stack Overflow
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...
Using the star sign in grep - Stack Overflow
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 …
grepping using the result of previous grep - Stack Overflow
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 …
How to perform grep operation on all files in a directory?
Apr 3, 2024 · 435 Working with xenserver, and I want to perform a command on each file that is in a directory, grep ping some stuff out of the output of the command and appending it in a file. I'm clear …
Grep: how to add an "OR" condition? - Unix & Linux Stack Exchange
Dec 1, 2011 · How can I introduce a conditional OR into grep? Something like, grepping a file's type for (JPEG OR JPG), and then sending only those files into the photos folder. For example. I know how …
linux - How to grep for the dollar symbol ($)? - Stack Overflow
hello5 $$$ % cat temp | grep "$$$" Illegal variable name. % cat temp | grep "\$\$\$" Variable name must contain alphanumeric characters. % I want to grep for $$$ and I expect the result to be % cat temp | …