linux - What is the point of "grep -q" - Stack Overflow
May 16, 2019 · Here's an example of grep -q: scanning the output of a command for a particular value, then performing an action if the value is found: ... If the list of docker contexts contains dm-manager …
What is the difference between grep -e and grep -E option?
grep understands three different versions of regular expression syntax: “basic,” “extended” and “perl.” In GNU grep, there is no difference in available functionality between basic and extended syntaxes.
How do I recursively grep all directories and subdirectories?
Feb 16, 2016 · Get the first matched files from grep command and get all the files don't contain some word, but input files for second grep comes from result files of first grep command.
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.
How to perform grep operation on all files in a directory?
Apr 3, 2024 · 437 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 …
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...
linux - How to search and replace using grep - Stack Overflow
I need to recursively search for a specified string within all files and subdirectories within a directory and replace this string with another string. I know that the command to find it might look...
What is the difference between `grep`, `egrep`, and `fgrep`?
Jan 8, 2017 · From "man grep": three variant programs egrep, fgrep and rgrep are available. egrep is the same as grep -E. fgrep is the same as grep -F. rgrep is the same as grep -r. Direct invocation as …
Grep: how to add an "OR" condition? - Unix & Linux Stack Exchange
Dec 1, 2011 · The grep utility looks for patterns inside files; it's irrelevant if what you care about is the file's name. Shell wildcard patterns are the way to match files by their names.
Find all files containing a specific text (string) on Linux
Jun 6, 2013 · How do I find all files containing a specific string of text within their file contents? The following doesn't work. It seems to display every single file in the system. find / -type f -exec grep -H '