Count line lengths in file using command line tools

Question

Problem

If I have a long file with lots of lines of varying lengths, how can I count the occurrences of each line length?

Example:

file.txt

this is a sample file with several lines of varying length 

Running count_line_lengths file.txt would give:

Length Occurences 1      1 2      2 4      3 5      1 6      2 7      2 

Ideas?

Answer 1

This

• counts the line lengths using awk, then
• sorts the (numeric) line lengths using sort -n and finally
• counts the unique line length values uniq -c.

$ awk '{print length}' input.txt | sort -n | uniq -c       1 1       2 2       3 4       1 5       2 6       2 7 

In the output, the first column is the number of lines with the given length, and the second column is the line length.

Answer 2

Pure awk

awk '{++a[length()]} END{for (i in a) print i, a[i]}' file.txt  4 3 5 1 6 2 7 2 1 1 2 2