SSH wrapper

ssh-wrapper.sh

#!/bin/bash

# Usage:
#
#   [VERBOSE=-v]
#   [PROFILE=<profile>] 
#   [IDENTITY=<key>]
#       ssh-wrapper.sh [cmd] <host> [args]
#
# just symlink to the wrapper to automatically set PROFILE

[ ${#@} -gt 0 ] || { >&2 echo ' insufficient arguments'; exit 1; }

case `uname -o` in
  Cygwin*) 
	WHICH='\which --skip-functions --skip-alias'
	;;
esac
: ${WHICH:=which}
: ${SSH:=`$WHICH ssh 2>/dev/null`}
: ${SCP:=`$WHICH scp 2>/dev/null`}
: ${SFTP:=`$WHICH sftp 2>/dev/null`}
: ${SCREEN:=`$WHICH screen 2>/dev/null`}

[ -x "$SSH" -a -x "$SCP" -a -x "$SFTP" ] || { 
    >&2 echo -e " missing binaries!\n  SSH=$SSH\n  SCP=$SCP\n  SFTP=$SFTP\n"
    exit 2;
  }

# compute from wrapper filename
: ${PROFILE:=`basename -s .sh "$0"`}

# disable Screen
for s in ${NO_SCREEN:-git rsync}; do
  [ "${PROFILE##*.}" = "$s" ] && { unset SCREEN; break; }
done


function _ssh() {
  # environment:
  #   SCREEN   - if set but empty, disable use of screen
  #   PROFILE  - name of SSH configuration file (-F)
  #   IDENTITY - path to identity file (-i)

  shopt -s extglob
  local _screen _conf _ident _cmd

  if [ "${TERM%.*}" = "screen" ]; then
    _screen="$SCREEN";
    TERM=${TERM/screen./}
    TERM=${TERM/screen/}
#    : ${TERM:=linux}
  fi

  if [ -n "$PROFILE" ]; then 
    for _conf in {,${HOME:-\~}/.ssh/}{,config{_,.}}"$PROFILE"; do
      [ -r "$_conf" ] && break
    done
    [ -n "$_conf" ] || { >&2 echo "ERR! configuration ($PROFILE) not found"; return 1; }
  fi
  if [ -n "$IDENTITY" ]; then 
    for _ident in {,${HOME:-\~}/.ssh/}{,id_}"$IDENTITY"; do
      [ -r "$_ident" ] && break
    done
    [ -n "$_ident" ] || { >&2 echo "ERR! identity ($IDENTITY) not found"; return 1; }
  fi

  _cmd=SSH
  case ${1^^} in
    SCP|SFTP)
      _cmd=${1^^}
      ;&
    SSH)
      shift; 
      # disable Screen where persistent command output is helpful
      unset _screen
	;;
  esac

  ${DEBUG:+set -x}
  ${_screen:+$_screen -t "${PROFILE:+${PROFILE#adfs-ftf-}:}$1" ${TERM:+-T $TERM}} \
	${!_cmd} ${VERBOSE} ${_conf:+-F "$_conf"} ${_ident:+-i "$_ident"} "$@"
}

_ssh "$@"