How to Count Lines in the file of Linux

The practice of counting lines in the file is usually adopted by the developers to determine the length of their code or the program. They do so to find out the efficiency of the program, the program having fewer lines performing the same task compared to the program of greater lines is assumed to be more efficient.

In Linux, there are different methods to count the number of lines in the files, all of these methods are discussed in this article in detail.

How to count lines in the file in Linux

We have a text file in the home directory with the name “myfile.txt”, to display the contents of the text file, use the command:

$ cat myfile.txt

Method 1: Using the wc command

The one method to count the number of lines is by using the “wc” command with the “-l” flag which is used to display the count of lines:

$ wc -l myfile.txt

You can also use the wc command with the cat command to display the count of lines of a file:

$ cat myfile.txt | wc -l

Method 2: Using the awk command

Another method to count the lines of the file in Linux is by using the command of awk:

$ awk 'END{print NR}' myfile.txt

Method 3: Using the sed command

The “sed” command can also be used in Linux to display the line count of the file, the use of the sed command for the purpose of displaying a number of lines is mentioned below:

$ sed -n '$=' myfile.txt

Method 4: Using the Grep command

The “grep” command is used to search, but it can be used for counting the number of lines as well as to display them, for this purpose, run the following command and replace the “myfile.txt” with your file name in the command:

$ grep -c ".*" myfile.txt

In the above command, we have used the “-c” flag which counts the number of lines and “.*” is used as a regular pattern or we can say to find out the strings in the file, another way to use the grep command such that it also displays file name in output is the use of the “-H” flag:

$ grep -Hc ".*" myfile.txt

Method 5: Using the nl command

The number line command (nl) is used to display the numbered bullets with the lines of the file:

$ nl myfile.txt

If you want to display just the number of lines, then use the awk command with the nl command:

$ nl myfile.txt | tail -1 | awk '{print $1}'

Method 6: Using the Perl language command:

Perl language command can also be used for the counting of the lines of the files in Linux, to use Perl command to count the lines of the file “myfile.txt”, execute the command:

$ perl -lne 'END { print $. }' myfile.txt

Method 7: Using While loop

Another most commonly used method to count the number of lines of the large files is using the while loop. Type the following bash script in the text file, and save it with .sh extension:

#!/bin/bash
echo "Enter the file name"
read file_name
count=0
while read
do
  ((count=$count+1))
done < $file_name
echo $count

Execute the bash file using the bash command:

$ bash mycode.sh

In the above output, on the execution of the command, it asks for the file name whose lines are to be counted, types the file name, in our case, it is “myfile.txt”, so it displays the results.

Conclusion

To calculate the productivity of the programmers, the main parameter is the length of their code, which can be measured by counting the lines of the code file. In Linux, we can count lines in different ways that are discussed in this article, the most commonly used method is the wc command method.

from https://ift.tt/3JctnKh