Count occurrences of a char in a string using Bash

Question

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 echos the correct number of occurrences of t in var, but when the character is comma or semicolon, it prints out zero:

var = "text,text,text,text" 
num = `expr match $var [,]`
echo "$num"

Answer 1

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}'