#!/bin/bash
set -o history
date
last=$(echo `history |tail -n2 |head -n1` | sed 's/[0-9]* //')
echo "last command is [$last]"

case "1" in
  "1")
  date
  last=$(echo `history |tail -n2 |head -n1` | sed 's/[0-9]* //')
  echo "last command is [$last]"
  ;;
esac

Tue May 24 12:36:04 CEST 2011
last command is [date]
Tue May 24 12:36:04 CEST 2011
last command is [echo "last command is [$last]"]

#!/bin/bash
die() { echo >&2 -e "nERROR: $@n"; exit 1; }
run() { "$@"; code=$?; [ $code -ne 0 ] && die "command [$*] failed with error code $code"; }

case "1" in
  "1")
  run ls /opt
  run ls /wrong-dir
  ;;
esac

$ ./test.sh
apacheds  google  iptables
ls: cannot access /wrong-dir: No such file or directory

ERROR: command [ls /wrong-dir] failed with error code 2

trap 'previous_command=$this_command; this_command=$BASH_COMMAND' DEBUG
…
echo "last command is $previous_command"

cmd=$previous_command ret=$?
if [ $ret -ne 0 ]; then echo "$cmd failed with error code $ret"; fi

set -e
trap 'echo "exit $? due to $previous_command"' EXIT

echo !!

echo "Last command run was ["!:0"] with arguments ["!:*"]"

echo this is a test
echo !!

set -o history -o histexpand

#!/bin/bash

exit_trap () {
  local lc="$BASH_COMMAND" rc=$?
  echo "Command [$lc] exited with code [$rc]"
}

trap exit_trap EXIT
set -e

echo "foo"
false 12345
echo "bar"

foo
Command [false 12345] exited with code [1]

#!/bin/bash
set -x
echo some command here
echo last command

#!/bin/sh
./test.sh 2>&1 | grep '^+' | tail -n 1 | sed -e 's/^+ //'

echo last command

# This construct is needed, because of a racecondition when trying to obtain
   # both of last command and error. With this the information of last error is
   # implied by the corresponding case while command is retrieved.

   if   [[ "${?}" == 0 && "${_}" != "" ]] ; then
    # Last command MUST be retrieved first.
      LASTCOMMAND="${_}" ;
      RETURNSTATUS='✓' ;
   elif [[ "${?}" == 0 && "${_}" == "" ]] ; then
      LASTCOMMAND='unknown' ;
      RETURNSTATUS='✓' ;
   elif [[ "${?}" != 0 && "${_}" != "" ]] ; then
    # Last command MUST be retrieved first.
      LASTCOMMAND="${_}" ;
      RETURNSTATUS='✗' ;
      # Fixme: "$?" not changing state until command executed.
   elif [[ "${?}" != 0 && "${_}" == "" ]] ; then
      LASTCOMMAND='unknown' ;
      RETURNSTATUS='✗' ;
      # Fixme: "$?" not changing state until command executed.
   fi

# Because of a racecondition, both MUST be retrieved at the same time.
   declare RETURNSTATUS="${?}" LASTCOMMAND="${_}" ;

   if [[ "${RETURNSTATUS}" == 0 ]] ; then
      declare RETURNSYMBOL='✓' ;
   else
      declare RETURNSYMBOL='✗' ;
   fi