This code checks the type of a specified command using the type command, ensuring the command is provided as an argument.

The pushd command changes the current directory to foo and pushes it onto the directory stack, enabling easy navigation back using popd.

This demonstrates the use of the clear command to clear the terminal screen, with an alternative method (Ctrl-L) noted in the comment.

This demonstrates using subshells to execute commands in different directories without affecting the current shell's working directory.

This demonstrates running a background process with wait to ensure it completes before proceeding.

This demonstrates using the trap command to handle signals (SIGHUP, SIGINT, SIGTERM) for cleanup and graceful script termination.

This demonstrates using the type command to determine the type and location of the wget command.

This demonstrates downloading and executing a remote Bash script with arguments.

This demonstrates using PIPESTATUS to retrieve the exit status of commands in a pipeline for debugging or conditional logic.

This demonstrates re-executing the last command from the history using !!.

This demonstrates executing an inline Bash command using the bash -c command.

This demonstrates executing a script in the Bash shell.

This demonstrates executing a Bash script in debugging mode using the -x option to print each command as it is executed.

This demonstrates executing a Bash script with the -e option to enable immediate exit on error.

This demonstrates the usage of the exit command to terminate the current shell or terminal session.

This demonstrates the usage of the jobs command to list all currently running or stopped background jobs in the current shell session.

This demonstrates piping a command string into bash -s to execute it with an argument, showing dynamic Bash command execution.