Arguments

command [options…] [arguments…]

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An argument can be used to specify something for the command to act upon. The ls command can be given the name of a directory as an argument, and it will list the contents of that directory. In the next example, the Documents directory will be used as an argument:

sysadmin@localhost:~$ ls Documents
School           alpha-second.txt  food.txt     linux.txt     os.csv
Work             alpha-third.txt   hello.sh     longfile.txt  people.csv
adjectives.txt   alpha.txt         hidden.txt   newhome.txt   profile.txt
alpha-first.txt  animals.txt       letters.txt  numbers.txt   red.txt

The resulting output is a list of files contained with the Documents directory.

Because Linux is open source, there are some interesting secrets that have been added by developers. For example, the aptitude command is a package management tool available on some Linux distributions. This command will accept moo as an argument:

sysadmin@localhost:~$ aptitude moo  
There are no Easter Eggs in this program.