How to find lines containing a string in linux
LinuxStringFileSearchLinux Problem Overview
I have a file in Linux, I would like to diplay lines which contain a specific string in that file, how to do this?
Linux Solutions
Solution 1 - Linux
The usual way to do this is with grep
, which uses a [tag:regex] pattern to match lines:
grep 'pattern' file
Each line which matches the pattern will be output. If you want to search for fixed strings only, use grep -F 'pattern' file
.
Solution 2 - Linux
Besides grep
, you can also use other utilities such as awk
or sed
Here is a few examples. Let say you want to search for a string is
in the file named GPL
.
Your sample file
user@linux:~$ cat -n GPL
1 The GNU General Public License is a free, copyleft license for
2 The licenses for most software and other practical works are designed
3 the GNU General Public License is intended to guarantee your freedom to
4 GNU General Public License for most of our software;
user@linux:~$
1. grep
user@linux:~$ grep is GPL
The GNU General Public License is a free, copyleft license for
the GNU General Public License is intended to guarantee your freedom to
user@linux:~$
2. awk
user@linux:~$ awk /is/ GPL
The GNU General Public License is a free, copyleft license for
the GNU General Public License is intended to guarantee your freedom to
user@linux:~$
3. sed
user@linux:~$ sed -n '/is/p' GPL
The GNU General Public License is a free, copyleft license for
the GNU General Public License is intended to guarantee your freedom to
user@linux:~$
Hope this helps
Solution 3 - Linux
/tmp/myfile
first line text
wanted text
other text
the command
$ grep -n "wanted text" /tmp/myfile | awk -F ":" '{print $1}'
2
The -n
switch to grep prepends any matched line with the line number (followed by :
), while the second command uses the colon as a column separator (-F ":"
) and prints out the first column of any line. The final result is the list of line numbers with a match.
Solution 4 - Linux
The grep family of commands (incl egrep, fgrep) is the usual solution for this.
$ grep pattern filename
If you're searching source code, then ack may be a better bet. It'll search subdirectories automatically and avoid files you'd normally not search (objects, SCM directories etc.)
Solution 5 - Linux
Write the queue job information in long format to text file
qstat -f > queue.txt
Grep job names
grep 'Job_Name' queue.txt