you can also try the variable replacement that bash have:

echo $PATH
/sbin:/bin:/usr/sbin:/usr/bin

echo ${PATH/\/usr\/sbin:}
/sbin:/bin:/usr/bin

that is this works like ${variable/text-to-remove-in-this-variable}

so $PATH=${PATH/\/usr\/sbin:}

you can also do a find and replace:

echo ${PATH/\/usr\/sbin:/\/usr\/local\/sbin:}
/sbin:/bin:/usr/local/sbin:/usr/bin

the nasty part here is the need to escape the / character, but works well :)

higuita

A much easier way to go is to let the builtin readline functions do more of the work.
Add this to your .inputrc

"\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f"

What it says in english is: "If I hit ^Xp, then on the commandline say PATH=$PATH. Then use escape-control-e
to cause any variables to be expanded. Then go to the beginning of the line, then go forwards by one word and then go forward by one character."

This will leave your cursor right on the first character of the value of your PATH.

After you add your sequence to the .inputrc, just say ^X^R to cause your .inputrc to be re-read.

Testing the above with

PATH=/home/user/bin:/one:/home/user/bin:/two:/home/user/bin

I'm getting the following result:

:/one:/two:/home/user/bin

Instead I would suggest the following

PATH=$(echo $PATH | sed -e 's;\(^/home/user/bin:\|:/home/user/bin$\|:/home/user/bin\(:\)\);\2;g')

that gives us the following result:

/one:/two

I know my test PATH is a little extreme, as you shouldn't normally see the same path more than once in your PATH. But real life systems aren't always "normal".