You might save some time and have a little fun by putting some aliases and functions in your .bashrc file. You can put functions or aliases in .bash_profile or .bashrc in your home directory. But by using .bashrc instead of .bash_profile, they’ll be read in not only when you log in, but whenever you start a new shell such as by launching an xterm, using su, etc. Your .bash_profile is read only when you log in. You might also want to look at /etc/profile and /etc/bashrc, these are the system-wide bash initialization files which are read in for every user and serve as the defaults. These should only be changed when necessary for all users, and is usually not a good place to put functions and aliases. The idea here is to personalize your environment and make it easier for you to be lazy.
Aliases
I usually put them at the very top or the very bottom of .bashrc to keep them all together. Aliases are one-liners, nicknames for commands that are too long or hard to remember to type every time.
I get tired of typing this:
[usr-3@srv-3 usr-3]$ ls -al | more
Let’s call it lam instead. But first make sure there’s not already a command called lam in my path:
[usr-3@srv-3 usr-3]$ which lam
It returns nothing, so we’re ok. I’ll edit /usr-3/.bashrc and add the line:
alias lam="ls -al | more"
We’ll have to read it in, otherwise I’d have to launch a new shell to get it:
[usr-3@srv-3 usr-3]$ source ~/.bashrc [usr-3@srv-3 usr-3]$ lam total 1354 drwxr-xr-x 32 usr-3 users 3072 Oct 17 08:32 . drwxr-xr-x 5 root root 1024 Jul 22 17:26 .. -rw-r--r-- 1 usr-3 users 5422 Oct 17 08:00 .X.err -rw-r--r-- 1 usr-3 users 5742 Dec 8 1998 .Xdefaults -rw-r--r-- 1 usr-3 users 46 May 7 1996 .Xmodmap -rw-r--r-- 1 usr-3 users 1940 Jul 22 16:06 .acrorc -rw-r--r-- 1 usr-3 users 0 Sep 2 11:23 .addressbook -rw------- 1 usr-3 users 2285 Sep 2 11:23 .addressbook.lu -rw------- 1 usr-3 users 12288 Oct 17 08:33 .article.swp -rw------- 1 usr-3 users 5853 Oct 17 08:13 .bash_history -rw-r--r-- 1 usr-3 users 1379 Oct 17 08:32 .bashrc -rw------- 1 usr-3 users 12288 Oct 17 08:32 .bashrc.swp -rw-r--r-- 1 usr-3 users 0 Nov 19 1995 .dayplan -rw------- 1 usr-3 users 0 May 8 1996 .dayplan.priv -rw-r--r-- 1 usr-3 users 208 Nov 17 1995 .dvipsrc -rw-r--r-- 1 usr-3 users 4143 Mar 15 1999 .emacs -rw-r--r-- 1 usr-3 users 1168 Feb 3 1998 .exrc drwxr-xr-x 13 usr-3 users 1024 Sep 30 16:18 .gimp-1.1 -rw-r--r-- 1 usr-3 users 5376 Aug 28 1996 .gimprc drwx------ 2 usr-3 users 1024 Jan 2 2000 .grok --More--
Some other examples:
Get a summary of the disk usage in human readable format
alias duh=”du -h –max-depth=1″
[usr-3@srv-3 music]$ duh . 689M ./d7 192M ./misc_tunes 749M ./mike 1.6G .
kill everything netscape:
alias dienet=’kill `ps auxwww | grep netscape | cut -c10-15`’
(notice the use of single quotes around the alias, double quotes take away the command substitution magic of the backticks.)
kill it really dead:
alias dienet9=’kill -9 `ps auxwww | grep netscape | cut -c10-15`’
You can also define aliases on the command line, but of course they won’t persist beyond the life of the shell.
[usr-3@srv-3 music]$ alias smithandjones="ssh -l smith jones" [usr-3@srv-3 music]$ smithandjones smith@jones's password: Linux 2.2.16. No mail. jones:/home/smith$
Back on srv-3, if I launch a new shell I lose the alias:
[usr-3@srv-3 music]$ bash [usr-3@srv-3 music]$ smithandjones bash: smithandjones: command not found
Functions
A function is like a shell script that you can put in your .bashrc file. This is good for things that won’t fit on a single command line or which require logic or looping. As with aliases or shell scripts, work out the commands at the prompt before you try to run them as a function from your files. Unlike a shell script, no new process is executed to interpret functions.
Here’s a function for something I get tired of doing by hand:
function fame {
wget http://www.slashdot.org -O ~/slashdot.html
FAME=`grep "Urbana Dergahad" ~/slashdot.html`
if test -n "$FAME"
then
mail mom -s "Look Ma I'm Famous" < ~/slashdot.html
else echo "sorry...."
fi
}
So I add it to my .bashrc and read it in:
[usr-3@srv-3 usr-3]$ vi .bashrc [usr-3@srv-3 usr-3]$ . .bashrc [usr-3@srv-3 usr-3]$ fame sorry....
Always the same! Oh well. You might be able to think of some more practical and less hopeless examples!
