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.
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 with logic operators - Unix & Linux Stack Exchange
Jan 5, 2015 · Is there a grep-like utility that will enable me to do grep searches with logic operators. I want to be able to nest and combine the logical constructs freely. For example, stuff like this should be
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 …
linux - Grep command with multiple patterns - Stack Overflow
Dec 12, 2019 · Hi i am currently use this to grep: $ grep -nri --exclude-dir=DELIVERY_REL "xxxxxx\.h" --colour --include=*.{c,h} I am trying to fine tune the search results of my grep to include multiple …
grep -P no longer works. How can I rewrite my searches?
May 21, 2013 · brew install grep Then it's available as ggrep (GNU grep). it doesn't replaces the system grep (you need to put the installed grep before the system one on the PATH). The version installed …
How to perform grep operation on all files in a directory?
433 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 on the …
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 …
regex - How to invert a grep expression - Stack Overflow
The following grep expression successfully lists all the .exe and .html files in the current directory and sub directories. ls -R |grep -E .*[\.exe]$\|.*[\.html]$
How can I grep for this or that (2 things) in a file?
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. In …