How to print the count of pattern at each line?

Question

I need to print the count of a matching string at the end of each line.

An example for matching foo:

foo,bar,foo,foo
bar,foo,bar,bar
foo,foo,bar,bar

Result :

foo,bar,foo,foo,3
bar,foo,bar,bar,1
foo,foo,bar,bar,2

I have checked this link(How to count the number of a specific character in each line?) but no luck.

If `foobar` existed in a line should that be counted as matching `foo` or not? What if the string to match was `fo.` and `fox` existed in the line - should that count? You asked for a count of strings - you didn't say if it should be full or partial words but in any case at least some of the answers you got are counting partially matching regexps. — Ed Morton, Sep 22 '21 at 22:18

score 11 · Answer 1 · answered Aug 25 '18 at 17:47

11

We can use awk with gsub to get the count of occurrence.

 awk '{print $0","gsub(/foo/,"")}' file

Output:

foo,bar,foo,foo,3
bar,foo,bar,bar,1
foo,foo,bar,bar,2

answered Aug 25 '18 at 17:47

Siva

9,017
8
56
86

This would count `foofoo` in one field as two matches. It is unclear whether this is intended or not. – Kusalananda Oct 15 '22 at 18:51

score 1 · Answer 2 · answered Aug 25 '18 at 20:56

1

Perhaps with a mixture of bash and grep

$ while read -r line; do 
    echo -n "$line -> " 
    grep -o foo <<<"$line" | wc -l 
  done < /path/to/my-input-file

foo,bar,foo,foo -> 3
bar,foo,bar,bar -> 1
foo,foo,bar,bar -> 2

answered Aug 25 '18 at 20:56

shalomb

197
6

score 0 · Answer 3 · answered Aug 25 '18 at 23:57

In case anyone also wanted something in Python. Specify the filename and the magic word to count over.

#!/usr/bin/python3
# magic_word_count.py
# Takes a filename and magic word and prints the number of times the word
# appears on each line of the file.
#
# ./magic_word_count.py myfile.txt foo
#
import sys 
filename = sys.argv[1]
magic_word = sys.argv[2]

with open(filename, 'r') as f:
    for line in f.readlines():
        words = line.strip().split(',')
        print(len([word for word in words if word == magic_word]))

Usage:

$ cat myfile.txt 
foo,bar,foo,foo
bar,foo,bar,bar
foo,foo,bar,bar

$ ./magic_word_count.py myfile.txt foo
3
1
2

score 0 · Answer 4 · answered Oct 15 '22 at 19:02

Using awk and assuming that the input is "simple" CSV (no embedded commas or newlines):

awk -v string="foo" -F, '
    BEGIN { OFS = FS }
    {
        sum = 0
        for (i = 1; i <= NF; ++i) sum += $i == string
        $(NF+1) = sum
    }; 1' file

This takes the string that we want to count occurrences of and then iterates through the fields of each record, counting exact matches. The accumulated sum of matching fields is then added as a new field at the end of the record, and the record is printed.

How to print the count of pattern at each line?

4 Answers4

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