Trick 1: Perform mkdir and cd using a single command
Sometimes when you create a new directory, you may cd to the new directory immediately to perform some work as shown below.# mkdir -p /tmp/subdir1/subdir2/subdir3
# cd /tmp/subdir1/subdir2/subdir3
# pwd
/tmp/subdir1/subdir2/subdir3
Wouldn’t it be nice to combine both mkdir and cd in a single command? Add the following to the .bash_profile and re-login.$ vi .bash_profile
function mkdircd () { mkdir -p "$@" && eval cd "\"\$$#\""; }
Now, perform both mkdir and cd at the same time using a single command as shown below:
# mkdircd /tmp/subdir1/subdir2/subdir3
[Note: This creates the directory and cd to it automatically]
# pwd
/tmp/subdir1/subdir2/subdir3
Trick 2: Prompt Command
Bash shell executes the content of the PROMPT_COMMAND just before displaying the PS1 variable.ramesh@dev-db ~> export PROMPT_COMMAND="date +%H:%M:%S"
22:08:42
ramesh@dev-db ~>
[Note: This displays the PROMPT_COMMAND and PS1 output on different lines]
If you want to display the value of PROMPT_COMMAND in the same line as the PS1, use the echo -n as shown below.ramesh@dev-db ~> export PROMPT_COMMAND="echo -n [$(date +%H:%M:%S)]"
[22:08:51]ramesh@dev-db ~>
[Note: This displays the PROMPT_COMMAND and PS1 output on the same line]
Trick 3: Change color of prompt using tput command
You can also change color of the PS1 prompt using tput as shown below:$ export PS1="\[$(tput bold)$(tput setb 4)$(tput setaf 7)\]\u@\h:\w $ \[$(tput sgr0)\]“
tput Color Capabilities:
- tput setab [1-7] – Set a background color using ANSI escape
- tput setb [1-7] – Set a background color
- tput setaf [1-7] – Set a foreground color using ANSI escape
- tput setf [1-7] – Set a foreground color
tput Text Mode Capabilities:
- tput bold – Set bold mode
- tput dim – turn on half-bright mode
- tput smul – begin underline mode
- tput rmul – exit underline mode
- tput rev – Turn on reverse mode
- tput smso – Enter standout mode (bold on rxvt)
- tput rmso – Exit standout mode
- tput sgr0 – Turn off all attributes
Color Code for tput:
- 0 – Black
- 1 – Red
- 2 – Green
- 3 – Yellow
- 4 – Blue
- 5 – Magenta
- 6 – Cyan
- 7 – White
Trick 4: Change the history file name using HISTFILE
By default, history is stored in ~/.bash_history file. Add the following line to the .bash_profile and relogin to the bash shell, to store the history command in .commandline_warrior file instead of .bash_history file. I’m yet to figure out a practical use for this. I can see this getting used when you want to track commands executed from different terminals using different history file name.# vi ~/.bash_profile
HISTFILE=/root/.commandline_warrior
