Problem:
Bash alias is a great way to create a simple name for complex commands. Use it to make your life in Bash command line simpler!
Solution:
First, lets use alias command to see what Bash aliases are already defined:
$> alias alias cljsbuild='lein trampoline cljsbuild ' alias la='ls -A' alias ll='ls -lAF'
alias command just prints list of all defined aliases. It’s the same as passing -p parameter: alias -p.
Now we can define our own Bash alias for frequently used command, which in our example is listing all files in reverse order by time:
$> alias lt='ls -ltr'
Let’s verify that the alias is defined:
$> alias alias cljsbuild='lein trampoline cljsbuild ' alias la='ls -A' alias ll='ls -lAF' alias lt='ls -ltr'
As you can see it’s the 4th of the aliases. From now on you can run it using the new command: lt.
So, let’s execute it:
$> lt /boot total 122927 drwxr-xr-x 2 root root 12288 Mar 31 2013 lost+found -rw-r--r-- 1 root root 178680 Mar 12 2014 memtest86+_multiboot.bin -rw-r--r-- 1 root root 178176 Mar 12 2014 memtest86+.elf -rw-r--r-- 1 root root 176500 Mar 12 2014 memtest86+.bin -rw------- 1 root root 6412672 Apr 10 21:03 vmlinuz-3.16.0-34-generic -rw------- 1 root root 3502413 Apr 10 21:03 System.map-3.16.0-34-generic -rw-r--r-- 1 root root 171819 Apr 10 21:03 config-3.16.0-34-generic -rw-r--r-- 1 root root 1207327 Apr 10 21:03 abi-3.16.0-34-generic -rw-r--r-- 1 root root 30304372 Apr 14 16:04 initrd.img-3.16.0-34-generic -rw------- 1 root root 6414272 Apr 14 22:48 vmlinuz-3.16.0-36-generic -rw------- 1 root root 3502913 Apr 14 22:48 System.map-3.16.0-36-generic -rw-r--r-- 1 root root 171808 Apr 14 22:48 config-3.16.0-36-generic -rw-r--r-- 1 root root 1206938 Apr 14 22:48 abi-3.16.0-36-generic -rw-r--r-- 1 root root 30311331 May 4 08:54 initrd.img-3.16.0-36-generic -rw------- 1 root root 6416256 May 5 16:46 vmlinuz-3.16.0-37-generic -rw------- 1 root root 3502913 May 5 16:46 System.map-3.16.0-37-generic -rw-r--r-- 1 root root 171808 May 5 16:46 config-3.16.0-37-generic -rw-r--r-- 1 root root 1206938 May 5 16:46 abi-3.16.0-37-generic -rw-r--r-- 1 root root 30310319 May 11 11:20 initrd.img-3.16.0-37-generic drwxr-xr-x 5 root root 1024 May 11 11:20 grub
It’s good idea to put frequently used aliases in ~/.bash_aliases file and include from ~/.bashrc like so:
if [ -f ~/.bash_aliases ]; then . ~/.bash_aliases fi
This makes them always accessible when you use Bash command line.
