How can I use the UNIX shell to count the number of times a letter appears in a text file?

Question

I have a few text files and I\'d like to count how many times a letter appears in each?

Specifically, I\'d like to use the UNIX shell to do this, in the form of: cat fil

Answer 1

There's also awk:

$ echo -e "hello world\nbye all" | awk -Fl '{c += NF - 1} END {print c}'
5

Change -Fl to -F.

This works by setting the field delimiter to the character specified by -F, then accumulating the number of fields on each line - 1 (because if there's one delimiter, there are two fields - but we should only count 1).