Shell Operations XK0-006 Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   What is the primary purpose of the pipe (`|`) operator in a shell command?

   • ATo combine two commands into a single executable.
   • BTo redirect output to a file.
   • CTo send the standard output of one command to the standard input of another command.
   • DTo run commands in the background.
   Reveal Solution Discussion Select an answer first
2. 7application · easy

   A developer wants to make an environment variable named APP_ENV with the value 'production' available to all child processes launched from the current shell. Which command should the developer use?

   • Aset APP_ENV=production
   • Bexport APP_ENV=production
   • CAPP_ENV=production
   • Denv APP_ENV=production
   Reveal Solution Discussion Select an answer first
4. 8foundation · easy

   What is the primary purpose of the PATH environment variable?

   • AIt specifies the directories the shell searches for executable commands.
   • BIt lists all files that can be executed by the current user.
   • CIt stores the current working directory path.
   • DIt defines the default text editor used by the system.
   Reveal Solution Discussion Select an answer first
5. 9foundation · easy

   What is the effect of using `>>` for output redirection?

   • AIt overwrites the file with the command's output.
   • BIt appends output to the end of an existing file.
   • CIt creates a new file only if the file does not exist.
   • DIt redirects standard error to the file.
   Reveal Solution Discussion Select an answer first
6. 10expert · hard

   A user has a script that relies on a custom command located in ~/bin. The script is run from a cron job, but the command is not found. The user has verified that ~/bin is in PATH for interactive shells. What is the most likely reason and the best fix?

   • AThe script is owned by another user; change ownership.
   • BCron does not source ~/.bashrc, so PATH is minimal; use the full path to the command in the cron job or set PATH explicitly in the cron entry.
   • CThe script is not executable; run chmod +x ~/bin/command.
   • DThe script has a shebang error; fix the first line.
   Reveal Solution Discussion Select an answer first