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 file | .... do stuff...

Is there a way I can get the wc command to do this?

Answer 1

grep char -o filename | wc -l

Answer 2

try it with

grep  [PATTERN] -o [FILE] | wc -l

and please do not use cat if not needed.

Answer 3

Alternative to grep:

sed 's/[^x]//g' filename | tr -d '\012' | wc -c

where x is the character you want to count.

Answer 4

There's also awk:

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

Change -Fl to -F<your character>.

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).

Answer 5

Another alternative:

tr -d -C X <infile | wc -c

where X is the character or string of characters you want to count and infile is the input file.