I would like to search and find all files which contain a word called “main()” for all directories located in $HOME/project/school. How do I use the grep command to find text including all subdirs under Unix or Linux operating systems?
The grep command is used to search text for patterns (words) specified on the command line. You need to use the following syntax:
Tutorial details | |
---|---|
Difficulty | Easy (rss) |
Root privileges | No |
Requirements | grep |
Time | N/A |
grep -r 'word' /path/to/dir
The -r option is used to search recursively through an entire directory tree. For example, the following would search all files in the current directory and in all of its subdirectories including their subdirectories for every line containing the word “main()”:
grep -r 'main()' ~/projects/school
You can also display the name of each file from which output would normally have been printed with the -l option:
grep -rl 'main()' ~/projects/school
You can print the file name for each match with -H option:
grep -rH 'main()' ~/projects/school
Finally, you can display line number too with the -n option:
grep -rHn 'main()' ~/projects/school
The -i option instructs grep to ignore case. Thus, for instance, the the following example could very easily be converted to a case-insensitive search as follows (match main(), MAIN(), mAiN() and so on):
grep -rHni 'main()' ~/projects/school
In this example, search for an IP address 192.168.1.5:
grep -Hrn --color '\<192.168.1.5\>' /etc
Sample outputs:
🐧 5 comments so far... add one ↓
Category | List of Unix and Linux commands |
---|---|
File Management | cat |
Firewall | Alpine Awall • CentOS 8 • OpenSUSE • RHEL 8 • Ubuntu 16.04 • Ubuntu 18.04 • Ubuntu 20.04 |
Network Utilities | dig • host • ip • nmap |
OpenVPN | CentOS 7 • CentOS 8 • Debian 10 • Debian 8/9 • Ubuntu 18.04 • Ubuntu 20.04 |
Package Manager | apk • apt |
Processes Management | bg • chroot • cron • disown • fg • jobs • killall • kill • pidof • pstree • pwdx • time |
Searching | grep • whereis • which |
User Information | groups • id • lastcomm • last • lid/libuser-lid • logname • members • users • whoami • who • w |
WireGuard VPN | Alpine • CentOS 8 • Debian 10 • Firewall • Ubuntu 20.04 |
Hi,
Thanks for this article
That’s great !!
I always did
# find /path/to/search | xargs grep ‘main()’
with your method you have more control over the output.
Great article!
ack is better
good articel