Bash check if exists in
- bash check if key exists in dictionary
- bash check if executable exists in path
- bash check if string exists in variable
- bash check if string exists in list
- bash check if file exists in current directory
- bash check if string exists in array
- bash check if key exists in associative array
- bash check if file exists in directory
- bash check if line exists in file
- bash check if exists in array
