-# meant to be sourced. copy/pasted from https://iankelling.org/git/?p=errhandle;a=summary
-
-bash-trace() {
- local -i argc_index=0 arg frame i start=${1:-1} max_indent=8 indent
- local source
- local extdebug=false
- if [[ $(shopt -p extdebug) == *-s* ]]; then
- extdebug=true
- fi
-
- for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
- argc=${BASH_ARGC[frame]}
- argc_index+=$argc
- ((frame < start)) && continue
- if (( ${#BASH_SOURCE[@]} > 1 )); then
- source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
- fi
- indent=$((frame-start+1))
- indent=$((indent < max_indent ? indent : max_indent))
- printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
- if $extdebug; then
- for ((i=argc_index-1; i >= argc_index-argc; i--)); do
- printf " %s" "${BASH_ARGV[i]}"
- done
- fi
- echo \'
- done
+#!/bin/bash
+# Bash Error Handler
+# Copyright (C) 2020 Ian Kelling <ian@iankelling.org>
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+# This is a single file library, just source this file. When an error
+# happens, we print a stack trace then exit. In an interactive shell, we
+# return from functions instead of exiting. If err-cleanup is a command,
+# it runs before the stack trace. Functions are documented inline below
+# for additional use cases.
+#
+# Note: occasionally the line numbers are off a bit (at least in Bash
+# 5.0). This appears to be a bash bug. I plan to report it next time it
+# happens to me.
+#
+# Please email me if you use this or have anything to contribute. I'm
+# not aware of any users yet Ian Kelling <ian@iankelling.org>.
+#
+# Tested on bash 4.4.20(1)-release (x86_64-pc-linux-gnu) and
+# 5.0.17(1)-release (x86_64-pc-linux-gnu).
+#
+# Related: see my bash script template repo at https://iankelling.org/git.
+
+
+# TODO: investigate to see if we can format output betting in case of
+# subshell failure. Right now, we get independent trace from inside and
+# outside of the subshell. Note, errexit + inherit_errexit doesn't have
+# any smarts around this either.
+
+if ! test "$BASH_VERSION"; then echo "error: shell is not bash" >&2; exit 1; fi
+
+#######################################
+# err-catch: Setup trap on ERR to print stack trace and exit (or return
+# if the shell is interactive). This is the most common use case so we
+# run it after defining it, you can call err-allow to undo that.
+#
+# This also sets pipefail because it's a good practice to catch more
+# errors.
+#
+# Note: In interactive shell, stack calling line number is not
+# available, so we print function definition lines.
+#
+# Note: This works like set -e, which has one unintuitive feature: If
+# you use a function as part of a conditional, eg: func && come_cmd, a
+# failed command within func won't trigger an error.
+#
+# Globals
+#
+# err_catch_ignore Array containing glob patterns to test against
+# filenames to ignore errors from in interactive
+# shell. Initialized to ignore bash-completion
+# scripts on debian based systems.
+#
+# err-cleanup If set, this command will run just before exiting.
+#
+# _err_func_last Used internally in err-bash-trace-interactive
+#
+#######################################
+err-catch() {
+ set -E;
+ if [[ $- == *i* ]]; then
+ if ! test ${err_catch_ignore+defined}; then
+ err_catch_ignore=(
+ '/etc/bash_completion.d/*'
+ '*/bash-completion/*'
+ )
+ fi
+ declare -i _err_func_last=0
+ if [[ $- != *c* ]]; then
+ shopt -s extdebug
+ fi
+ # shellcheck disable=SC2154
+ trap '_err-bash-trace-interactive $? "${PIPESTATUS[*]}" "$BASH_COMMAND" ${BASH_ARGC[0]} "${BASH_ARGV[@]}" || return $?' ERR
+ else
+ # Man bash on exdebug: "If set at shell invocation, arrange to
+ # execute the debugger". We want to avoid that, but I want this file
+ # to be sourceable from bash startup files. noninteractive ssh and
+ # sources .bashrc on invocation. login_shell sources things on
+ # invocation.
+ #
+ # extdebug allows us to print function arguments in our stack trace.
+ if ! shopt login_shell >/dev/null && [[ ! $SSH_CONNECTION ]]; then
+ shopt -s extdebug
+ fi
+ trap err-exit ERR
+ fi
+ set -o pipefail
}
+# This is the most common use case so run it now.
+err-catch
+
+#######################################
+# Undo err-catch/err-catch-interactive
+#######################################
+err-allow() {
+ shopt -u extdebug
+ set +E +o pipefail
+ trap ERR
+}
+
+#######################################
+# err-exit: Print stack trace and exit
+#
+# Use this instead of the exit command to be more informative.
+#
+# usage: err-exit [-EXIT_CODE] [MESSAGE]
+#
+# EXIT_CODE Default: $? if it is nonzero, otherwise 1.
+# MESSAGE Print MESSAGE to stderr. Default:
+# ${BASH_SOURCE[1]}:${BASH_LINENO[0]}: `$BASH_COMMAND' returned $?
+#
+# Globals
+#
+# err-cleanup If set, this command will run just before exiting.
+#
+#######################################
+err-exit() {
+ # vars have _ prefix so that we can inspect existing set vars without
+ # too much overwriting of them.
+ local _err=$? _pipestatus="${_pipestatus[*]}"
+
+ # This has to come before most things or vars get changed
+ local _msg="${BASH_SOURCE[1]}:${BASH_LINENO[0]}: \`$BASH_COMMAND' returned $_err"
+ local _cmdr="$BASH_COMMAND" # command right. we chop of the left, keep the right.
+ if [[ $_pipestatus != "$_err" ]]; then
+ _msg+=", PIPESTATUS: $_pipestatus"
+ fi
+ set +x
+ if [[ $1 == -* ]]; then
+ _err=${1#-}
+ shift
+ elif (( ! _err )); then
+ _err=1
+ fi
+ if [[ $1 ]]; then
+ _msg="$1"
+ fi
-errcatch() {
- set -E; shopt -s extdebug
- _err-trap() {
- err=$?
- exec >&2
- set +x
- echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}:in \`$BASH_COMMAND' returned $err"
- bash-trace 2
- set -e
- "${_errcatch_cleanup[@]}"
- echo "$0: exiting with code $err"
- exit $err
- }
- trap _err-trap ERR
- set -o pipefail
+ ## Begin printing vars from within BASH_COMMAND ##
+ local _var _chars _l
+ local -A _vars
+ while [[ $_cmdr ]]; do
+ _chars="${#_cmdr}"
+ _cmdr="${_cmdr#*$}"
+ _cmdr="${_cmdr#{}"
+ if (( _chars == ${#_cmdr} )); then
+ break
+ fi
+ _var="${_cmdr%%[^a-zA-Z0-9_]*}"
+ if [[ ! $_var || $_var == [0-9]* ]]; then
+ continue
+ fi
+ _vars[${_var}]=t
+ done
+ #echo "iank ${_vars[*]}"
+ #set |& grep ^password
+ # in my small test, this took 50% longer than piping to grep.
+ # That seems a small enough penalty to stay in bash here.
+ if (( ${#_vars[@]} )); then
+ set |& while read -r _l; do
+ for _var in "${!_vars[@]}"; do
+ case $_l in
+ ${_var}=*) printf "%s\n" "$_l" >&2 ;;
+ esac
+ done
+ done
+ fi
+ ## End printing vars from within BASH_COMMAND ##
+
+ printf "%s\n" "$_msg" >&2
+ err-bash-trace 2
+ set -e # err trap does not work within an error trap
+ if type -t err-cleanup >/dev/null; then
+ err-cleanup
+ fi
+ printf "%s: exiting with status %s\n" "$0" "$_err" >&2
+ exit $_err
+}
+
+#######################################
+# Print stack trace
+#
+# usage: err-bash-trace [FRAME_START]
+#
+# This function is called by the other functions which print stack
+# traces.
+#
+# It does not show function args unless you first run:
+# shopt -s extdebug
+# which err-catch does for you.
+#
+# FRAME_START Optional variable to set before calling. The frame to
+# start printing on. default=1. If ${#FUNCNAME[@]} <=
+# FRAME_START + 1, don't print anything because we are at
+# the top level of the script and better off printing a
+# general message, for example see what our callers print.
+#
+#######################################
+err-bash-trace() {
+ local -i argc_index=0 frame i frame_start=${1:-1}
+ local source_loc
+ if (( ${#FUNCNAME[@]} <= frame_start + 1 )); then
+ return 0
+ fi
+ for ((frame=0; frame < ${#FUNCNAME[@]}; frame++)); do
+ argc=${BASH_ARGC[frame]}
+ argc_index+=$argc
+ if ((frame < frame_start)); then continue; fi
+ if (( ${#BASH_SOURCE[@]} > 1 )); then
+ source_loc="${BASH_SOURCE[frame]}:${BASH_LINENO[frame-1]}:"
+ fi
+ printf " from %sin \`%s" "$source_loc" "${FUNCNAME[frame]}" >&2
+ if shopt extdebug >/dev/null; then
+ for ((i=argc_index-1; i >= argc_index-argc; i--)); do
+ printf " %s" "${BASH_ARGV[i]}" >&2
+ done
+ fi
+ echo \' >&2
+ done
+ return 0
}
-errcatch
+#######################################
+# Internal function for err-catch. Prints stack trace from interactive
+# shell trap.
+#
+# Usage: see err-catch-interactive
+#######################################
+_err-bash-trace-interactive() {
+ if (( ${#FUNCNAME[@]} <= 1 )); then
+ return 0
+ fi
+
+ for pattern in "${err_catch_ignore[@]}"; do
+ # shellcheck disable=SC2053
+ if [[ ${BASH_SOURCE[1]} == $pattern ]]; then
+ return 0
+ fi
+ done
+
+ local ret bash_command argc pattern i last
+ last=$_err_func_last
+ _err_func_last=${#FUNCNAME[@]}
+ # We have these passed to us because they are lost inside the
+ # function.
+ ret=$1
+ pipestatus="$2"
+ bash_command="$3"
+ argc=$(( $4 - 1 ))
+ shift 4
+ argv=("$@")
+ # The trap returns a nonzero, then gets called again. This condition
+ # tells us if is that has happened by checking if we've gone down a
+ # stack level.
+ if (( _err_func_last >= last )); then
+ printf "ERR: \`%s\' returned %s" "$bash_command" $ret >&2
+ if [[ $pipestatus != "$ret" ]]; then
+ printf ", PIPESTATUS: %s" "$pipestatus" >&2
+ fi
+ echo >&2
+ fi
+ printf " from \`%s" "${FUNCNAME[1]}" >&2
+ if shopt extdebug >/dev/null; then
+ for ((i=argc; i >= 0; i--)); do
+ printf " %s" "${argv[i]}" >&2
+ done
+ fi
+ printf "\' defined at %s:%s\n" "${BASH_SOURCE[1]}" "$(declare -F "${FUNCNAME[1]}"|awk "{print \$2}")" >&2
+ if [[ -t 1 ]]; then
+ return $ret
+ else
+ # Part of an outgoing pipe, avoid getting get us stuck in a weird
+ # subshell if we returned nonzero, which would happen in a situation
+ # like this:
+ #
+ # tf() { while read -r line; do :; done < <(asdf); };
+ # tf
+ #
+ # Note: exit $ret also avoids the stuck subshell problem, and I
+ # can't notice any difference, but this seems more proper.
+ return 0
+ fi
+}
iankelling.org / git / automated-distro-installer / blobdiff