Search Text File In UNIX

How do I search the input text files for lines matching given words or strings under UNIX operating systems?

To search for a particular word or string in a file, use the grep command.

Syntax

The basic syntax of the grep command is as follows:

grep string fileName
grep word fileName
grep "word1 word2" fileName

grep string fileName
grep word fileName
grep "word1 word2" fileName

Examples

For example, to find SXI ADMIN’s email id, type grep, and the file containing the information:

grep Vivek users.txt
grep "SXI ADMIN" users.txt
grep "Gite" users.txt

grep Vivek users.txt
grep "SXI ADMIN" users.txt
grep "Gite" users.txt

Sample outputs:

SXI ADMIN    123-455-676 [email protected]

To search word apple in all text file (*.txt) enter:

grep apple *.txt

grep apple *.txt

You can also search for lines without a certain words. For example, display all line that do not contain the word “usb”

grep -v "usb" *

grep -v "usb" *

See more grep command examples here.

Posted by: SXI ADMIN

The author is the creator of SXI LLC and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.