Linux Command Line & Shell Scripting Flashcards

What does the chmod 755 filename command set as permissions?

Answer: Owner: rwx, Group: r-x, Others: r-x

7=rwx for owner, 5=r-x for group, 5=r-x for others.

Which command shows the manual page for the ls command?

Answer: man ls

The man command opens the manual page for any installed command.

In bash, how do you define a function named greet?

Answer: function greet() { ... }

The bash syntax for a function is: function name() { commands; } or name() { commands; }.

What does the command wc -l file.txt report?

Answer: Line count

wc -l counts the number of newline characters, effectively reporting the number of lines.

Which command removes an alias named ll that was set in the current shell session?

Answer: unalias ll

The unalias command removes a previously defined alias from the current shell.

What does the semicolon ; do when placed between two commands on the same line?

Answer: Runs both commands regardless of the first command's exit status

A semicolon is a simple command separator; the second command always runs after the first finishes.

Which of these is a valid way to read user input into a variable named NAME in bash?

Answer: read NAME

The read built-in reads a line from stdin and stores it in the given variable.