Bash script to find the frequency of every letter in a file

Question

I am trying to find out the frequency of appearance of every letter in the english alphabet in an input file. How can I do this in a bash script?

Answer 1

Similar to mouviciel's answer above, but more generic for Bourne and Korn shells used on BSD systems, when you don't have GNU sed, which supports \n in a replacement, you can backslash escape a newline:

sed -e's/./&\
/g' file | sort | uniq -c | sort -nr

or to avoid the visual split on the screen, insert a literal newline by type CTRL+V CTRL+J

sed -e's/./&\^J/g' file | sort | uniq -c | sort -nr