dot/bashrc: Show Git branch name in the prompt, if machinery available.

[profile] / dot / bashrc

### -*-bash-*-
###
### Bash session things

## Only do this if we haven't done it before.  (Note that this guard isn't
## exported, so subshells will need to make their own arrangements.)
if [ -z "$__mdw_bashrc" ]; then
__mdw_bashrc=done

## If we've not run the main profile yet, we should do that first.  It sets
## up things we rely on.  Also, if there's a system script, we should run
## that too.
[ -z "$__mdw_profile" -a -r $HOME/.bash_profile ] && . $HOME/.bash_profile
[ -r /etc/bashrc ] && . /etc/bashrc

## Completion.
[ -r /etc/bash_completion ] && . /etc/bash_completion
[ -r $HOME/.bash_completion ] && . $HOME/.bash_completion

## Set the temporary directory again.  (If we've switched users, we'll want a
## different temporary directory.)
[ "${TMPDIR+yes}" ] || eval `tmpdir -b`

###--------------------------------------------------------------------------
### Prompt hacking.

## Only bother if the shell is interactive.
if [ -t 0 ]; then

  ## Fancy highlighting in some terminals.
  marker=${STY+'\[\ek\e\\\]'}
  case "$TERM" in
    linux*|screen*|xterm*|vt100*|eterm*)
      case "$(tput bold)" in
	"") bold="\[$(tput md)\]" unbold="\[$(tput me)\]" ;;
	*) bold="\[$(tput bold)\]" unbold="\[$(tput sgr0)\]" ;;
      esac
      gitcolour="\[$(tput setaf 6)\]"
      rccolour="\[$(tput setaf 1)\]"
      uncolour="\[$(tput op)\]"
      nl="\[\r\]"
      ;;
    *)
      bold='' unbold='' nl='' gitcolour='' rccolour='' uncolour='';;
  esac

  ## Choose the right delimiters.  Highlight root prompts specially;
  ## highlight when I'm running as some other user.  Highlight when this
  ## isn't the outermost shell on the terminal.
  if (( EUID == 0 )); then
    left=`echo « | iconv -f UTF-8 -t //translit`
    right=`echo » | iconv -f UTF-8 -t //translit`
  else
    case $USER in
      mdw|mwooding|nemo) u="" left="[" right="]" ;;
      *) u="\\u@" left="{" right="}" ;;
    esac
    if [ "$__mdw_tty" = "`tty`" ]; then
      left="<" right=">"
    else
      export __mdw_tty="`tty`"
    fi
  fi

  ## If this session is insecure then highlight that.
  if [ -z "$SSH_CLIENT" ] &&
    [ "$__mdw_sechost" != "`hostname`" ]
    then
    sec_l='(' sec_r=')'
  fi

  ## Build the prompt string.
  if type __git_ps1 >/dev/null 2>&1; then
    git="$unbold$gitcolour\$(rc=\$?;__git_ps1;exit \$rc)$uncolour$bold"
  else
    git=""
  fi
  rc="$unbold$rccolour\$(rc=\$?;case \$rc in 0);;"
  rc="$rc*)echo -n \" rc=\$rc\";;esac;exit \$rc)$uncolour$bold"
  PS1="$nl$bold$left$sec_l$u\\h$sec_r \\w$git$rc$marker$right$unbold"
  PS2="$PS1 $bold>$unbold "
  unset nl bold unbold left right sec_l sec_r marker
  unset gitcolour rccolour uncolour git rc
fi

###--------------------------------------------------------------------------
### Other shell tweaking.

## Random shell tweaks.
notify=1
set -b
shopt -u cdable_vars
shopt -s cdspell
shopt -s checkhash
shopt -s checkwinsize
shopt -s cmdhist
shopt -u dotglob
shopt -s expand_aliases
shopt -s extglob
if (( ${BASH_VERSINFO[0]} >= 4 )); then shopt -s globstar; fi
shopt -s gnu_errfmt
shopt -s histappend
shopt -s histreedit
shopt -u histverify
shopt -s hostcomplete
shopt -s huponexit
shopt -s interactive_comments
shopt -s lithist
shopt -u mailwarn
shopt -u nocaseglob
shopt -u nullglob
shopt -s promptvars
shopt -u shift_verbose
shopt -s sourcepath
HISTCONTROL=ignorespace:erasedups

## Some handy aliases.
alias cx='chmod a+x'
alias which="command -v"
alias rc="rc -l"
alias ssync="rsync -e ssh"
rootly () {
  case $# in 0) set -- "${SHELL-/bin/sh}" ;; esac
  $__MDW_ROOTLY "$@"
}
alias r=rootly
alias re="rootly $EDITOR"
alias pstree="pstree -hl"
alias cdtmp='cd ${TMPDIR-/tmp}'
alias pushtmp='pushd ${TMPDIR-/tmp}'
alias e="$EDITOR"
alias svn="svnwrap svn"
alias @="ssh"

###--------------------------------------------------------------------------
### Colour output.

## Arrange for `ls' output to be in colour.
if [ -x /usr/bin/dircolors -o -x /usr/local/bin/dircolors ]; then
  eval `dircolors -b ~/.dircolors`
else
  unset LS_COLORS
fi

unalias ls 2>/dev/null || :; function ls () {
  if [ -t 1 ]; then
    command ls $LS_OPTIONS ${LS_COLORS+--color=auto} "$@"
  else
    command ls "$@"
  fi
}

## Arrange for `grep' output to be in colour.
export GREP_COLORS="mt=01;31:ms=01;31:mc=031;31:fn=36:ln=36:bn=36:se=34"

greplike () {
  declare grep=$1; shift
  if [ -t 1 ]; then
    command $grep ${GREP_COLORS+--color=always} "$@" | mdw-pager
  else
    command $grep "$@"
  fi
}
alias grep="greplike grep"
alias egrep="greplike egrep"
alias fgrep="greplike fgrep"
alias zgrep="greplike zgrep"

## Turn off pagers inside Emacs shell buffers.
case "$INSIDE_EMACS" in
  2[2-9].*,comint | [3-9][0-9].*,comint) export PAGER=cat ;;
esac

###--------------------------------------------------------------------------
### More complicated shell functions.

## xt [@HOST] XTERM-ARGS
##
## Open a terminal, maybe on a remote host.
xt () {
  case "$1" in
    @*)
      local remote=${1#@} title
      shift
      if [ $# -gt 0 ]; then
	title="xterm [$remote] $1"
      else
	title="xterm [$remote]"
      fi
      (xterm -title "$title" -e ssh $remote "$@" &)
      ;;
    *)
      (xterm "$@" &)
      ;;
  esac
}

## core [y|n]
##
## Tweak core dumps on and off, or show the current status.
core () {
  case "x$1" in
    xon|xy|xyes) ulimit -Sc `ulimit -Hc` ;;
    xoff|xn|xno) ulimit -Sc 0 ;;
    x)
      local l=`ulimit -Sc`
      case $l in
	0) echo "Core dumps disabled" ;;
	unlimited) echo "Core dumps enabled" ;;
	*) echo "Core dump limit is $l blocks" ;;
      esac
      ;;
    *)
      echo >&2 "usage: core [y|n]"
      return 1
      ;;
  esac
}

## world [NAME]
##
## Set current security world to NAME.  With no NAME, print the currently
## selected world.
world () {
  local nfast=${NFAST_HOME-/opt/nfast}
  local kmdata
  case "$#" in
    0)
      echo "${NFAST_KMDATA#$nfast/kmdata-}"
      ;;
    *)
      if [ -d "$1" ]; then
	kmdata=$1
      elif [ -d "$nfast/kmdata-$1" ]; then
	kmdata=$nfast/kmdata-$1
      else
	echo >&2 "world: can't find world $1"
	return 1
      fi
      shift
      case "$#" in
	0) export NFAST_KMDATA=$kmdata ;;
	*) "$@" ;;
      esac
      ;;
  esac
}

## Fix `man' under Slowaris.
case "$MACHTYPE" in
  *solaris*)
    man () {
      declare -i i=0
      declare arg
      declare -a man
      for arg; do
	case "$arg" in [0-9]*) man[i+=1]="-s" ;; esac
	man[i+=1]="$arg"
      done
      command man "${man[@]}"
    }
    ;;
esac

###--------------------------------------------------------------------------
### Path hacks.

## path-add [VAR] DIR
##
## Add DIR to the beginning of PATH-like variable VAR (defaults to PATH) if
## it's not there already.
path-add () {
  local pathvar export dir val
  case $# in
    1) pathvar=PATH dir=$1 export="export PATH";;
    2) pathvar=$1 dir=$2 export=:;;
    *) echo >&2 "Usage: $0 [VAR] DIR";;
  esac
  eval "val=\$$pathvar"
  case ":$val:" in
    *:"$dir":*) ;;
    *) val=$dir:$val ;;
  esac
  eval "$pathvar=\$val"
  $export
}

## path-remove [VAR] DIR
##
## Remove DIR from PATH-like variable VAR (defaults to PATH); it's not an
## error if DIR isn't in VAR.
path-remove () {
  local pathvar export dir val
  case $# in
    1) pathvar=PATH dir=$1 export="export PATH";;
    2) pathvar=$1 dir=$2 export=:;;
    *) echo >&2 "Usage: $0 [VAR] DIR";;
  esac
  eval "val=\$$pathvar"
  case ":$val:" in
    :"$dir":) val= ;;
    :"$dir":*) val=${val#$dir:} ;;
    *:"$dir":) val=${val%:$dir} ;;
    *:"$dir":*) val=${val/:$dir:/:} ;;
  esac
  eval "$pathvar=\$val"
  $export
}

## pathhack [-f] +HACK|-HACK...
##
## Each HACK refers to a subdirectory of `~/bin/hacks'.  A hack name preceded
## by `+' adds the directory to the PATH; a `-' removes.  Adding a hack
## that's already on the PATH doesn't do anything unless `-f' is set, in
## which case it gets moved to the beginning.  With no arguments, print the
## currently installed hacks.
pathhack () {
  if [ $# -eq 0 ]; then
    local IFS=:
    for e in $PATH; do
      case "$e" in
	"$HOME/bin/hacks/"*)
	  echo ${e#$HOME/bin/hacks/}
	  ;;
      esac
    done
    return
  fi
  local force=nil
  local path=$PATH
  while [ $# -gt 0 ]; do
    arg=$1
    case "$arg" in
      -f | --force)
	force=t
	shift
	continue
	;;
      --)
	shift
	break
	;;
      [-+]*)
	;;
      *)
	break
	;;
    esac
    hack=${arg#[+-]}
    dir=$HOME/bin/hacks/$hack
    [ -d "$dir" ] || {
      echo "$0: path hack $hack not found"
      return 1
    }
    case "$arg,$force,:$PATH:" in
      -*,*,*:"$dir":*)
	path-remove path "$dir"
	;;
      +*,t,*:"$dir":*)
	path-remove path "$dir"
	path-add path "$dir"
	;;
      +*,nil,*:"$dir":*)
	;;
      +*,*)
	path-add path "$dir"
	;;
    esac
    shift
  done
  if [ $# -eq 0 ]; then
    PATH=$path
    export PATH
  else
    PATH=$path "$@"
  fi
}

###--------------------------------------------------------------------------
### Finishing touches.

## For `root' use -- some simple molly-guards.
if (( UID == 0 )); then
  alias rm='rm -i' cp='cp -i' mv='mv -i'
  set -o noclobber
fi

## Run any local hooks.
[ -f "$HOME/.bashrc-local" ] && . "$HOME/.bashrc-local"

## Close the `__mdw_bashrc' guard.
fi

###----- That's all, folks --------------------------------------------------