Counting the number of dots in a string

Question

How do I count the number of dots in a string in BASH? For example

VAR=\"s454-da4_sd.fs_84-df.f-sds.a_as_d.a-565sd.dasd\"

# Variable VAR contains 5 dots
         


        

Answer 1

VAR="s454-da4_sd.fs_84-df.f-sds.a_as_d.a-565sd.dasd"
dot_count=$( IFS=.; set $VAR; echo $(( $# - 1 )) )

This works by setting the field separator to "." in a subshell and setting the positional parameters by word-splitting the string. With N dots, there will be N+1 positional parameters. We finish by subtracting one from the number of positional parameters in the subshell and echoing that to be captured in dot_count.