HPR2349: Customizing my bash prompt

Hosted by Windigo on 2017-08-03 00:00:00

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Basic bash prompt information

Variables and files
- .bashrc: the RC file where all of this stuff can be set
- PS1: main prompt variable
- PS2: continuation prompt
- PROMPT_COMMAND: a bash function name, run every time prompt is displayed
Colors
- Uses escape sequences
- There are problems with prompts and escape sequences
  - Multiple escaping
  - String interpretation and variable expansion
- tput to the rescue!
  - Takes away the need for complex escape codes
  - Must run tput init at the beginning of your .bashrc file
  - TL;DR: Use tput for color strings, add them at the last possible moment, with brackets and backslashes
Embedding bash scripts
- Single quotes are king
- Will be run every time PS1 is evaluated
- Otherwise, only run at time of assignment

Two lines
- Information/status line
- Prompt line
Status line
- Starts with current username
  - Changes color when user has mail
- Next is the hostname (truncated)
  - Separated by an @ symbol, like an email address
  - Changes color when the system is in need of a reboot
  - Checks for /run/reboot_required
- Current directory
  - Separated from previous items by a pipe
  - Truncated with a tilde if user's home is in the path
  - Prepended with a number indicating the directory stack, if present
  - Appended with the git (±) symbol if we're in a git branch, followed by the name of the branch
Prompt line
- A blue » character
- Prepended with the number of background processes spawned from this terminal

Screenshot:

A screenshot of my bash prompt, both initially and with all of the bells and whistles showing

Editor's Note: added 2017-08-05