Pattern: Missing target shell for Bash script
Issue: -
Different shells support different features. To give effective advice, ShellCheck needs to know which shell your script is going to run on. You will get a different numbers of warnings about different things depending on your target shell.
ShellCheck normally determines your target shell from the shebang (having e.g. #!/bin/sh as the first line). The shell can also be specified from the CLI with -s, e.g. shellcheck -s sh file.
If you don't specify shebang nor -s, ShellCheck gives this message and proceeds with some default (bash).
Example of incorrect code:
echo "$RANDOM" # Does this work?Example of correct code:
#!/bin/sh
echo "$RANDOM" # Unsupported in sh. Produces warning.or
#!/bin/bash
echo "$RANDOM" # Supported in bash. No warnings.