Pattern: Missing absolute path to the interpreter
Issue: -
The script's interpreter, as specified in the shebang, does not start with a /.
The interpreter should always be specified by absolute path to ensure that the script can be executed from any directory. When it's not, it's generally a typo like in the problematic example.
If you don't know where the interpreter is and you hoped to use #! bash, this is not an option. Use /usr/bin/env instead:
#!/usr/bin/env bash
echo "Hello World"While not required by POSIX, env can essentially always be found in /usr/bin and will search the PATH for the specified executable.
Example of incorrect code:
#!bin/sh
echo "Hello World"Example of correct code:
#!/bin/sh
echo "Hello World"