Ubuntu – How to shorten the bash prompt’s current path to one letter per directory

bashbashrccommand lineprompt

I can't remember where, but I've already seen the bash prompt's current path shortened in an interesting way: every directory contained in the path (excepted the last one) is replaced by its first letter only. For instance: path/to/some/directory would be shortened to p/t/s/directory.

How can I reproduce that behavior ?

Best Answer

After playing with this for a while I got the answer you require:

Add this to your .bashrc file in your home directory, exit the terminal and renter it and you will get you prompt.

PS1='$(eval "sps")$ '
sps() {
   echo "$PWD" | sed -r 's|/([^/]{,2})[^/]*|/\1|g'
}

It uses the declared function sps() to evaluate the path every time the variable PS1 which is the prompt, is displayed

/ho/de/De/Ap/Ti$ pwd
/home/deth/Desktop/Apps/Tivo
/ho/de/De/Ap/Ti$

Or...if you insist on the one letter

PS1='$(eval "sps")$ '
sps() {
   echo "$PWD" | sed -r 's|/(.)[^/]*|/\1|g'
}

Which displays:

/h/d/D/A/T$ pwd
/home/deth/Desktop/Apps/Tivo
/h/d/D/A/T$

To change it for the current terminal instance only

Just enter PS1='\u:\W\$ ' and press enter.

To change it "permanently"

In your ~/.bashrc, find the following section:

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi

Remove the @\h, and replace the \w with an uppercase \W, so that it becomes:

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u\[\033[00m\]:\[\033[01;34m\]\W\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u:\W\$ '
fi

Save, exit, close terminal and start another to see the result.

Tons more options!

See here for a more extensive howto, with many more options
See this answer for using up a tiny Python script to set the prompt so that the shortening only occurs when you are deep in a directory structure.

Ubuntu – How to display $PATH as one directory per line

You can do this with any one of the following commands, which substitutes all occurrences of : with new lines \n.

sed:

$ sed 's/:/\n/g' <<< "$PATH"

tr:

$ tr ':' '\n' <<< "$PATH"

python:

$ python -c 'import sys;print(sys.argv[1].replace(":","\n"))' "$PATH"

Best Answer

Related Solutions

Ubuntu – How to shorten the command line (bash) prompt

To change it for the current terminal instance only

To change it "permanently"

Tons more options!

Ubuntu – How to display $PATH as one directory per line

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