I need to count the number of occurrences of a char in a string using Bash.
In the following example, when the char is (for example) t
, it
you can for example remove all other chars and count the whats remains, like:
var="text,text,text,text"
res="${var//[^,]}"
echo "$res"
echo "${#res}"
will print
,,,
3
or
tr -dc ',' <<<"$var" | awk '{ print length; }'
or
tr -dc ',' <<<"$var" | wc -c #works, but i don't like wc.. ;)
or
awk -F, '{print NF-1}' <<<"$var"
or
grep -o ',' <<<"$var" | grep -c .
or
perl -nle 'print s/,//g' <<<"$var"
awk works well if you your server has it
var="text,text,text,text"
num=$(echo "${var}" | awk -F, '{print NF-1}')
echo "${num}"
I would use the following awk
command:
string="text,text,text,text"
char=","
awk -F"${char}" '{print NF-1}' <<< "${string}"
I'm splitting the string by $char
and print the number of resulting fields minus 1.
If your shell does not support the <<<
operator, use echo
:
echo "${string}" | awk -F"${char}" '{print NF-1}'
also check this out, for example we wanna count t
echo "test" | awk -v RS='t' 'END{print NR-1}'
or in python
python -c 'print "this is for test".count("t")'
or even better, we can make our script dynamic with awk
echo 'test' | awk '{for (i=1 ; i<=NF ; i++) array[$i]++ } END{ for (char in array) print char,array[char]}' FS=""
in this case output is like this :
e 1
s 1
t 2
Building on everyone's great answers and comments, this is the shortest and sweetest version:
grep -o "$needle" <<< "$haystack" | wc -l
I Would suggest the following:
var="any given string"
N=${#var}
G=${var//g/}
G=${#G}
(( G = N - G ))
echo "$G"
No call to any other program