Help with a Terminal Command

I'm was troubleshooting another issue when this came up.

I found a website with a suggested solution for my problem, but it contains a terminal command I'm not familiar with, and it apparently has no man-page. I'm wondering if this means it's not actually a terminal command, but some kind of executable? Some googling didn't really get me a concrete answer, but I gathered it's something like the "ls" (list) command. Anyway, not a big problem, I just like to understand what a terminal command does before I use it, both for safety and because I enjoy learning about linux.

The command is

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~$ ll

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just two lower case L's

It's being used in the following context

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~$ ll /dev/disk/by-partuuid

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It's an alias.

Code:

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alias ll
alias

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alias is a built-in capability in bash. If you dig deep in the manual page for bash, you can find a description of it and other built-in capabilities. It's useful for making shortcuts for long, but frequently used, commands. It's down in the section on 'shell builtin commands'

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man bash

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Usually ll is short for ls -l. An alias indeed.

Thanks for the responses, I appreciate it!

Seems like enough commands are already "abbreviated" to an obfuscating degree... and now your telling me some of them also have aliases? *facepalm* :D

Another piece of trivia is that "ll" is not always defined. If you "ssh" to a remote server, sometimes you have to tediously type the full "ls -l". :)

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Originally Posted by dave2001

... and now your telling me some of them also have aliases?

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...well... they exist strictly for the user's benefit. You don't have to use them.

Short history:

*nix programmers are a lazy lot (lazy like a fox), so whenever possible, they invent shortcuts that can cut keystrokes. Aliases are an example of this sort of constructive laziness. Instead of having to type ls -l all the time, an alias is defined (only in some distros) so that a simple ll substitutes for ls -l. Admittedly, this specific alias is a rather lame one, but the following one may make a little more sense. I run a multitude of VMs in VirtualBox and must often check their virtual driver version with the command:

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modinfo vboxguest | grep -iw version

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By defining the alias vbinf for this string of commands, I not only save a lot of keystrokes, but also the need to remember the exact command string for something I don't use that frequently. For really long convoluted command strings, it's a godsend.

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type -f ll

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or

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alias ll

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Just enter the command alias to see all the aliases currently defined.