LCA Shell Scripting & Automation

Question 1

Which symbol is used to start a comment line in a shell script?

Accepted Answer

#

Answer

In shell scripts (and many other scripting languages), the hash symbol (`#`) is used to denote a comment line. Any text following the `#` on that line will be ignored by the shell interpreter. Comments are essential for documenting code, explaining logic, and making scripts more understandable for others and for future self-reference.

Question 2

What command runs a shell script named 'myscript.sh'?

Accepted Answer

sh myscript.sh

Answer

To run a shell script named `myscript.sh`, you can explicitly invoke the shell interpreter, such as `sh` (for Bourne shell compatible scripts) or `bash` (for Bash scripts), followed by the script's filename. This tells the system to execute the script using the specified shell. Alternatively, if the script has execute permissions and a shebang line, you can run it directly with `./myscript.sh`.

Question 3

Which command gives execute permission to a shell script?

Accepted Answer

chmod +x

Answer

The `chmod` command is used to change file permissions in Linux. The `+x` option specifically grants execute permission to a file, which is necessary for a shell script to be run directly as a program. Without execute permission, the script can only be read or modified, but not executed by simply typing its name.

Question 4

What does the 'echo' command do in a shell script?

Accepted Answer

Prints output

Answer

The `echo` command is a fundamental utility in shell scripting used to display text or the value of variables to the standard output, typically the terminal. It's commonly used for printing messages, debugging, or showing results within a script. For example, `echo "Hello World"` would print "Hello World".

Question 5

Which variable holds the name of the currently running script?

Accepted Answer

$0

Answer

In shell scripting, `$0` is a special variable that holds the name of the script itself as it was invoked. This is useful for various purposes, such as printing usage messages or determining the script's identity. Other variables like `$1`, `$@`, and `$#` refer to command-line arguments or their count.

(LCA) Certified Linux Administrator Practice Test

(LCA) Certified Linux Administrator Practice Test

LCA Shell Scripting & Automation