[SOLVED] How do I use grep to count the number of occurrences of a string

Issue

How do I use grep to count the number of occurrences of a string?

input:

.
├── a.txt
├── b.txt

// a.txt
aaa

// b.txt
aaa
bbb
ccc

Now I want to know how many times aaa and bbb appear.

output:

aaa: 2
bbb: 1

Solution

Just an idea:

grep -E "aaa|bbb|ccc" *.txt | awk -F: '{print $2}' | sort | uniq -c

This means:

grep -E "...|..." : extended grep, look for all entries

The result is given as:
a.txt:aaa
b.txt:aaa
b.txt:bbb
b.txt:ccc

awk -F: '{print $2}' : split the result in 2 columns, 
                       based on the semicolon, 
                       and only show the second column

sort | uniq -c : sort and count unique entries

Answered By - Dominique