bash stacktrace

gistfile1.sh

#!/usr/bin/env bash

#from https://gist.github.com/dvishniakov/86c83ef891d200674522c791589d42b3
# Provides stack trace when error occurs or when manually called
# $1 is message
# $2 is command
# ${ContinueOnErrors} controls whether to continue or stop script if error is catched.
# it helps during batch processing. -o errexit/errtrace also affects this
errexit() {
  local errno=$? # non-zero when this function is called via trap
  local bashopts=$-
  set +o xtrace # disabling debugging commands so output of this function will be clear
  echo "Error in ${BASH_SOURCE[1]}:${BASH_LINENO[0]}: '${@:2}' exited with code ${errno}: '${1}'">&2
  # Print out the stack trace described by $function_stack  
  if [ ${#FUNCNAME[@]} -gt 2 ]; then
    echo "Call tree:">&2
    for ((i=1;i<${#FUNCNAME[@]}-1;i++)); do
      echo " $i: ${BASH_SOURCE[$i+1]}:${BASH_LINENO[$i]} ${FUNCNAME[$i]}(...)">&2
    done
  fi
  set -${bashopts} # restoring options
  [ -n "${ContinueOnErrors-}" ] || exit "${errno:-1}"
}

# trap ERR to provide an error handler whenever a command exits nonzero
#  this is a more verbose version of set -o errexit
trap 'errexit "Trap catched" "${BASH_COMMAND}"' ERR
# setting errtrace(-E) allows our ERR trap handler to be propagated to functions,
#  expansions and subshells
# nounset(-u): error on expand of unset variable
# pipefail: if a piped command fails, it's error code is returned as error code of the whole pipeline
# errexit(-e): exit when command returns with an error. Just in case if something happens with the trap
set -o errtrace -o nounset -o pipefail -o errexit

# # examples
# # just test conditions and error will be trapped
# [ -n "" ]
# # or provide meaningful parameters yourself. Not clear how to get that [ -z "${BASH_SOURCE}" ] as a second parameter
# [ -z "${BASH_SOURCE}" ] || errexit "Empty value" "-z BASH_SOURCE"
# cd somewhere
# testFn() {
#   [ -n "${4:-}" ] || errexit "Not enough arguments" "$FUNCNAME $@"
#   cd somewhere
# }
# testFn 1 2 3