cross-shell-prompt

A clean, informative shell prompt for bash and zsh. Zero dependencies, just shell builtins. Drop it in and get a prompt that shows your last exit code, current git branch, and an abbreviated working directory.

Features

• Last command exit code indicator: green o on success, red x on failure
• Current git branch, detected by reading .git/HEAD directly (no git fork)
• Abbreviated working path: ~/projects/myapp becomes ~/p/myapp
• Optional hostname that shows automatically over SSH
• Color output by default, plain mode for dumb terminals or logs
• Works in bash 3.2+ and zsh 5+

What it looks like

o ~/p/myapp (main) $ xxx ~/p/myapp (main) $

The left prompt shows a normal successful command. The right shows what appears after a failing command (exit code 1 or higher).

Installation

Add one line to your shell config (~/.bashrc for bash, ~/.zshrc for zsh):

source /path/to/prompt.sh

Then start a new shell or run source ~/.bashrc (or ~/.zshrc).

Install via git clone

git clone https://github.com/cappy-dev/cross-shell-prompt.git
echo "source $(pwd)/cross-shell-prompt/prompt.sh" >> ~/.bashrc

For zsh, use ~/.zshrc instead.

Quick demo (no install needed)

./prompt.sh

Prints a sample prompt so you can see the format before installing.

Configuration

All settings are environment variables. Set them before sourcing the script.

CSP_SHOW_HOST

Set to 1 to always show the hostname (even outside SSH):

export CSP_SHOW_HOST=1
source /path/to/prompt.sh

The hostname shows automatically when SSH_CONNECTION or SSH_TTY is set.

Colors

Override any color before sourcing. Values are ANSI escape strings.

Variable	Default	Used for
CSP_COLOR_DIR	bold cyan	Working directory
CSP_COLOR_HOST	magenta	Hostname
CSP_COLOR_GIT	yellow	Git branch
CSP_COLOR_OK	green	Success indicator
CSP_COLOR_FAIL	red	Failure indicator
CSP_COLOR_RESET	reset	Color reset

Example with custom colors:

export CSP_COLOR_DIR=$'\033[1;34m'
source /path/to/prompt.sh

Disable colors

Call csp_disable_color after sourcing:

source /path/to/prompt.sh
csp_disable_color

Useful for dumb terminals or when piping shell output to a log.

How the path abbreviation works

The prompt keeps the first letter of each intermediate directory but shows the final directory in full. Your home directory is replaced with ~.

Full path	Prompt path
/home/user	~
/home/user/projects/myapp	~/p/myapp
/etc/systemd/system	/e/s/system
/var/log/nginx	/v/l/nginx
/	/

This keeps long paths short without hiding the last directory, which is the one you usually care about.

How git branch detection works (no git command needed)

The script walks up the directory tree until it finds a .git directory or file. It then reads .git/HEAD directly to determine the branch name. This avoids forking git on every prompt, which makes the prompt fast even in large repos.

Detached HEAD state shows the short commit hash followed by .... Tags show tag:NAME format.

Compatibility

Tested with:

• bash 3.2 (macOS default), 4.x, 5.x
• zsh 5.x

Not compatible with fish, tcsh, or other shells. The script uses PROMPT_COMMAND (bash) or precmd_functions (zsh) hooks that only exist in those two shells.

Files

• prompt.sh - the full script. Source this file from your shell config.
• LICENSE - MIT license.

License

MIT. See LICENSE.