What prefix is used to run a script located in the current directory when it is not in PATH?

• A. sh
• B. ./scriptname
• C. ./
• D. /usr/bin/bash

Answer: (C)

To run a script from the current directory when it’s not in PATH, you must specify a path that points to that location. The prefix ./ denotes the current directory, so the command would be ./scriptname to execute the script located there. This works because PATH is not searched for the current directory by default, a security measure that prevents accidentally running programs from your present working directory. Once you prefix with ./, the shell knows to look in the current directory for the script, provided it has execute permission and, ideally, a proper shebang line. If it doesn’t have execute permission, you can either grant it with chmod +x scriptname or run it by explicitly invoking an interpreter, like bash ./scriptname. The other options don’t specify the current directory: an interpreter path alone doesn’t target the script’s location, and a bare ./ would refer to the directory itself rather than a runnable file, while ./scriptname fully specifies the file but isn’t the single prefix—the prefix is ./ and the full command includes the script name.