# Frontend to controlling prompt
prompt() {
# What's done next depends on the first argument to the function
case $1 in
# Turn complex, colored PS1 and debugging PS4 prompts on
on)
# Declare the PROMPT_RETURN variable as an integer
declare -i PROMPT_RETURN
# Set up pre-prompt command
PROMPT_COMMAND='PROMPT_RETURN=$? ; history -a'
# If Bash 4.0 is available, trim very long paths in prompt
((BASH_VERSINFO[0] >= 4)) && PROMPT_DIRTRIM=4
# Basic prompt shape depends on whether we're in SSH or not
PS1=
if [[ -n $SSH_CLIENT || -n $SSH_CONNECTION ]] ; then
PS1=$PS1'\u@\h:'
fi
PS1=$PS1'\w'
# Add sub-commands; VCS, job, and return status checks
PS1=$PS1'$(prompt vcs)$(prompt job)$(prompt ret)'
# Add prefix and suffix
PS1='${PROMPT_PREFIX}'$PS1'${PROMPT_SUFFIX}'
# Add terminating "$" or "#" sign
PS1=$PS1'\$'
# Add > signs at the front of the prompt to show the current shell
# level
local i
for ((i = 0; i < SHLVL; i++)) ; do
PS1='>'$PS1
done
# Declare variables to contain terminal control strings
local format reset
# Disregard output and error from these tput(1) calls
{
# Count available colors
local -i colors
colors=$(tput colors || tput Co)
# Prepare reset code
reset=$(tput sgr0 || tput me)
# Check if we have non-bold bright green available
if ((colors >= 16)) ; then
format=$(
: "${PROMPT_COLOR:=10}"
tput setaf "$PROMPT_COLOR" ||
tput setaf "$PROMPT_COLOR" 0 0 ||
tput AF "$PROMPT_COLOR" ||
tput AF "$PROMPT_COLOR" 0 0
)
# If we have only eight colors, use bold green
elif ((colors >= 8)) ; then
format=$(
: "${PROMPT_COLOR:=2}"
tput setaf "$PROMPT_COLOR" ||
tput AF "$PROMPT_COLOR"
tput bold || tput md
)
# Otherwise, we just try bold
else
format=$(tput bold || tput md)
fi
} >/dev/null 2>&1
# String it all together
PS1='\['"$format"'\]'"$PS1"'\['"$reset"'\] '
PS2='> '
PS3='? '
PS4='+<$?> ${BASH_SOURCE:-$BASH}:${FUNCNAME[0]}:$LINENO:'
;;
# Revert to simple inexpensive prompts
off)
unset -v PROMPT_COMMAND PROMPT_DIRTRIM PROMPT_RETURN
PS1='\$ '
PS2='> '
PS3='? '
PS4='+ '
;;
# Git prompt function
git)
# Wrap as compound command; we don't want to see output from any of
# these git(1) calls
{
# Bail if we're not in a work tree--or, implicitly, if we don't
# have git(1).
[[ $(git rev-parse --is-inside-work-tree) == true ]] ||
return
# Refresh index so e.g. git-diff-files(1) is accurate
git update-index --refresh
# Find a local branch, remote branch, or tag (annotated or
# not), or failing all of that just show the short commit ID,
# in that order of preference; if none of that works, bail out
local name
name=$(
git symbolic-ref --quiet HEAD ||
git describe --tags --exact-match HEAD ||
git rev-parse --short HEAD
) || return
name=${name##*/}
[[ -n $name ]] || return
# Check various files in .git to flag processes
local proc
[[ -d .git/rebase-merge || -d .git/rebase-apply ]] &&
proc=${proc:+"$proc",}'REBASE'
[[ -f .git/MERGE_HEAD ]] &&
proc=${proc:+"$proc",}'MERGE'
[[ -f .git/CHERRY_PICK_HEAD ]] &&
proc=${proc:+"$proc",}'PICK'
[[ -f .git/REVERT_HEAD ]] &&
proc=${proc:+"$proc",}'REVERT'
[[ -f .git/BISECT_LOG ]] &&
proc=${proc:+"$proc",}'BISECT'
# Collect symbols representing repository state
local state
# Upstream HEAD has commits after local HEAD; we're "behind"
(($(git rev-list --count 'HEAD..@{u}'))) &&
state=${state}'<'
# Local HEAD has commits after upstream HEAD; we're "ahead"
(($(git rev-list --count '@{u}..HEAD'))) &&
state=${state}'>'
# Tracked files are modified
git diff-files --no-ext-diff --quiet ||
state=${state}'!'
# Changes are staged
git diff-index --cached --no-ext-diff --quiet HEAD ||
state=${state}'+'
# There are some untracked and unignored files
git ls-files --directory --error-unmatch --exclude-standard \
--no-empty-directory --others -- ':/*' &&
state=${state}'?'
# There are stashed changes
git rev-parse --quiet --verify refs/stash &&
state=${state}'^'
} >/dev/null 2>&1
# Print the status in brackets; add a git: prefix only if there
# might be another VCS prompt (because PROMPT_VCS is set)
printf '(%s%s%s%s)' \
"${PROMPT_VCS:+git:}" "$name" "${proc:+:"$proc"}" "$state"
;;
# Subversion prompt function
svn)
# Determine the repository URL and root directory
local key value url root
while [[ -z $url || -z $root ]] && IFS=: read -r key value ; do
case $key in
'URL') url=${value## } ;;
'Repository Root') root=${value## } ;;
esac
done < <(svn info 2>/dev/null)
# Exit if we couldn't get either--or, implicitly, if we don't have
# svn(1).
[[ -n $url && -n $root ]] || return
# Remove the root from the URL to get what's hopefully the branch
# name, removing leading slashes and the 'branches' prefix, and any
# trailing content after a slash
local branch
branch=${url/"$root"}
branch=${branch#/}
branch=${branch#branches/}
branch=${branch%%/*}
# Parse the output of svn status to determine working copy state
local symbol
local -i modified untracked
while ((!modified || !untracked)) && read -r symbol _ ; do
case $symbol in
*\?*) untracked=1 ;;
*) modified=1 ;;
esac
done < <(svn status 2>/dev/null)
# Add appropriate state flags
local state
((modified)) && state=${state}'!'
((untracked)) && state=${state}'?'
# Print the state in brackets with an svn: prefix
printf '(svn:%s%s)' "${branch:-unknown}" "$state"
;;
# VCS wrapper prompt function; print the first relevant prompt, if any
vcs)
local vcs
for vcs in "${PROMPT_VCS[@]:-git}" ; do
prompt "$vcs" && return
done
;;
# Show return status of previous command in angle brackets, if not zero
ret)
((PROMPT_RETURN)) && printf '<%u>' "$PROMPT_RETURN"
;;
# Show the count of background jobs in curly brackets, if not zero
job)
local -i jobc
while read -r ; do
((jobc++))
done < <(jobs -p)
((jobc)) && printf '{%u}' "$jobc"
;;
# No argument given, print prompt strings and vars
'')
declare -p PS1 PS2 PS3 PS4
;;
# Print error
*)
printf '%s: Unknown command %s\n' "${FUNCNAME[0]}" "$1" >&2
return 2
;;
esac
}
# Start with full-fledged prompt
prompt on