-# 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
+#!/bin/bash
+# Copyright (C) 2019 Ian Kelling
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Commentary: Print stack trace and exit/return on errors, or use
+# functions below for for more details and manual error handling. See
+# end of file for credits etc.
+
+#######################################
+# 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.
+#
+# 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
+ shopt -s extdebug
+ # shellcheck disable=SC2154
+ trap '_err-bash-trace-interactive $? "$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
- 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
+#######################################
+# 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 $?
+#
+# Globals
+#
+# err-cleanup If set, this command will run just before exiting.
+#
+#######################################
+err-exit() {
+ local err=$?
+ # This has to come before most things or vars get changed
+ local msg="${BASH_SOURCE[1]}:${BASH_LINENO[0]}: \`$BASH_COMMAND' returned $err"
+ set +x
+ if [[ $1 == -* ]]; then
+ err=${1#-}
+ shift
+ elif (( ! err )); then
+ err=1
+ fi
+ if [[ $1 ]]; then
+ msg="$1"
+ fi
+ printf "%s\n" "$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
+}
+
+#######################################
+# Internal function for err-catch. Prints stack trace from interactive
+# shell trap.
+#
+# Usage: see err-catch-interactive
+#######################################
+_err-bash-trace-interactive() {
+ if (( ${#FUNCNAME[@]} <= 1 )); then
+ return 0
+ fi
-errcatch() {
- set -E; shopt -s extdebug
- _err-trap() {
- err=$?
- 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 $err
- }
- trap _err-trap ERR
- set -o pipefail
+ for pattern in "${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
+ bash_command="$2"
+ argc=$(( $3 - 1 ))
+ shift 3
+ argv=("$@")
+ # The trap returns a nonzero, then gets called again. This condition
+ # tells us if we are the first.
+ if (( _err_func_last > last )); then
+ printf "ERR: \`%s\' returned %s\n" "$bash_command" $ret >&2
+ fi
+ printf " from \`%s" "${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
}
-errcatch
+# Credits etc:
+#
+# Related: see my bash script template repo at https://iankelling.org/git.
+#
+#
+# Please email me if you have a patches, bugs, feedback, or if you use
+# it or republish it since 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). If you test
iankelling.org / git / automated-distro-installer / blobdiff