Search

Couting the number of blank lines in a file

Counting the number of blank lines in a file.

Here are a few ways to count the number of blank lines in a file using shell scripting.

Assume we have a file named test which has the following contents :



Note that the above file has 10 blank lines includin the one at the end. Let see how we can count the same using commands or scripts

1. Using grep :



When -c option is used with grep, it counts the number of occurrences of the search string and outputs the same. 2. Using awk:



Awk reads one line of the file at a time, hence we compare each line with the blank line i.e. ^$ and increment a count whenever there is match and print the final count before exiting.

3. Using shell scripting :



Save the script as line_count.sh . Give it execute permission using

chmod 777 line_count.sh

And then execute it



The above script uses a while loop to pass through the file, one line at a time and on reading each line an "if" statement is used to comapre the line with the blank line. Note the use of double [ with the if statement. A single [ will not be able to interpret the regular expressions in an if statement. When the comparision is a success a count is incremented and the same is printed at the end.

3 comments:

  1. How to check if the file has read permission or not??? The file must be provided through command line argument

    ReplyDelete
  2. This comment has been removed by the author.

    ReplyDelete

Follow by Email