#!/bin/bash -e

set -o errexit # in case caller did not have -e in #! line

if test ! "$_util_sh_include_guard_utils"; then

_util_sh_include_guard_utils=1

isset() { test "${!1+isset}"; }

realpath() { readlink -f -- "$1"; }

include_guard_var() { realpath "$1"|builtin command sed 's/[^a-zA-Z0-9_]/_/g'; }

self_not_included() # usage: if self_not_included; then ... fi

{

	test $# -ge 1 || set -- "${BASH_SOURCE[1]}"

	local include_guard="$(include_guard_var "$1")"

	alias self_being_included=false

	! isset "$include_guard" && \

	{ eval "$include_guard"=1; alias self_being_included=true; }

}

# to load newly-defined aliases for use in functions in the same file:

## fi # load new aliases

## if self_being_included; then

# this is needed because aliases defined inside an if statement are not

# available inside that if statement

fi

if self_not_included "${BASH_SOURCE[0]}"; then

#### options

shopt -s expand_aliases

#### vars

set_var() { eval "$1"'="$2"'; }

set_inv() { set_var no_"$1" "$(test "${!1}" || echo 1)"; }

# usage: local var=...; local_inv

alias local_inv='declare "no_$var=$(test "${!var}" || echo 1)"'

unexport() { export -n "$@"; }

	# `declare +x` won't work because it defines the var if it isn't set

get_prefix_vars() { : "${prefix:?}"; eval echo '${!'$prefix'*}'; }

# usage: local prefix=..._; import_vars

# when used inside another alias 2+ levels deep, *must* be run inside a function

alias import_vars="$(cat <<'EOF'

: "${prefix:?}"

declare src_var dest_var

for src_var in $(get_prefix_vars); do

	dest_var="${src_var#$prefix}"

	declare "$dest_var=${!src_var}"; echo_vars "$dest_var"

done

EOF

)"

#### aliases

unalias() { builtin unalias "$@" 2>&- || true; } # no error if undefined

# usage: alias alias_='var=value run_cmd '

function run_cmd() { "$@"; }

alias run_cmd='"run_cmd" ' # last space alias-expands next word

#### functions

alias self='command "$FUNCNAME"' # usage: wrapper() { self ...; }

#### exceptions

# usage: cmd || { save_e; ...; rethrow; }

alias export_e='e=$?'

alias save_e='declare e=$?'

alias rethrow='return "$e"'

alias rethrow_subshell='exit "$e"'

fi # load new aliases

if self_being_included; then

# usage: try cmd...; ignore status; if catch status; then ...; fi; end_try

function try() { e=0; "$@" || { export_e; true; }; }

alias try='declare e; "try" ' # last space alias-expands next word

catch() { test "$e" -eq "$1"; e=0; }

ignore() { catch "$@" || true; }

alias end_try='rethrow'

alias end_try_subshell='rethrow_subshell'

fi # load new aliases

if self_being_included; then

#### integers

let!() { let "$@" || true; } # always returns true; safe to use for setting

	# "If the last ARG evaluates to 0, let returns 1" (`help let`)

bool2int() { try test ! "$1"; echo "$e"; } # empty->0; non-empty->1

#### strings

repeat() # usage: str=... n=... repeat

{

	: "${str?}" "${n:?}"; local n="$n" # will be modified in function

	for (( ; n > 0; n-- )); do printf '%q' "$str"; done

}

sed_ere_flag="$(test "$(uname)" = Darwin && echo E || echo r)"

sed() { self -"$sed_ere_flag" "$@";}

rtrim() { sed 's/[[:space:]]+$//' <<<"$1"; }

#### arrays

join() { local IFS="$delim"; echo "$*"; } # usage: delim=... join elems...

reverse() # usage: array=($(reverse args...))

{

	local i

	for (( i=$#; i > 0; i-- )); do printf '%q ' "${!i}"; done

}

contains() # usage: contains value in_array...

{

	local value="$1"; shift

	local elem

	for elem in "$@"; do if test "$elem" = "$value"; then return 0; fi; done

	return 1

}

#### paths

canon_rel_path()

{

	local path="$1"

	path="$(realpath "$path")" # canonicalize

	path="${path#$(pwd -P)/}" # remove any shared prefix with the current dir

	echo "$path"

}

# makes $1 a canon_rel_path if it's a filesystem path

alias cmd2rel_path="$(cat <<'EOF'

if test "$(type -t "$1")" = file && test -e "$1"; then # not relative to PATH

	declare _1="$1"; shift

	set -- "$(canon_rel_path "$_1")" "$@"

fi

EOF

)"

#### verbose output

err_fd=2 # stderr

usage() { echo "Usage: $1" >&2; return 2; }

### logging

log_fd=2 # stderr

if test "$explicit_errors_only"; then verbosity=0; fi # hide startup logging

# set verbosity

if isset verbose; then : "${verbosity:=$(bool2int "$verbose")}"; fi

if isset vb; then : "${verbosity:=$vb}"; fi

: "${verbosity=2}" # default

: "${verbosity:=0}" # ensure non-empty

export verbosity # propagate to invoked commands

: "${log_level_indent=| }" "${log_indent=}"

export log_level_indent log_indent # propagate to invoked commands

alias indent='declare log_indent="$log_indent$log_level_indent"'

# usage: in func:      PS4++; ...

#        outside func: PS4++; ...; PS4--

alias PS4++='declare PS4="${PS4:0:1}$PS4"'

alias PS4--='declare PS4="${PS4#${PS4:0:1}}"'

# usage: in func:      log++; ...

#        outside func: log++; ...; log--

alias log++='{ PS4++; declare verbosity="$verbosity"; let! verbosity--; }'

alias log--='{ PS4--; declare verbosity="$verbosity"; let! verbosity++; }'

fi # load new aliases

if self_being_included; then

can_log() { test "$verbosity" -gt 0; } # verbosity=0 turns off all logging

log() { if can_log; then echo "$log_indent$PS4$1" >&"$log_fd"; fi; }

# usage: symbol=... log_custom msg

log_custom()

{

	local log_indent="${log_indent//[^ ]/$symbol}" PS4="$symbol${PS4#?}"

	log "$@"

}

log_err() { symbol=* verbosity=1 log_fd="$err_fd" log_custom "$@"; }

log_info() { symbol='#' log_custom "$@"; }

# usage: cmd || { save_e; log_e; ...; rethrow; }

log_e() { log_err "command exited with error $e"; }

# usage: cmd || [type=...] die msg

die() { save_e; "log_${type:-err}" "$1"; rethrow; }

### command echoing

alias echo_params='log "$*"'

fi # load new aliases

if self_being_included; then

echo_cmd() { echo_params; }

## internal commands

.()

{

	cmd2rel_path; set -- . "$@"; (log++; echo_params; can_log) && indent || true

	builtin "$@"

}

echo_eval() { echo_params; builtin eval "$@"; }

## external commands

disable_logging() { echo_eval exec "$log_fd>/dev/null"; }

function command() # usage: [cmd_log_fd=|1|2|#] command extern_cmd...

# to view only explicitly-displayed errors: explicit_errors_only=1 script...

{

	cmd2rel_path; (echo_params; can_log) && indent || true

	(

		# the following redirections must happen in exactly this order

		if test "$cmd_log_fd"; then

			echo_eval exec "$cmd_log_fd>$(if (log++; can_log); then \

			echo "&$log_fd"; else echo /dev/null; fi)"

		fi

		if test "$cmd_log_fd" != 2; then # fd 2 not used for logging

			exec 2>&"$err_fd" # assume fd 2 used for errors

		fi

		exec -- "$@" # -- so cmd name not treated as `exec` option

	) || return

}

# auto-echo common external commands

for cmd in env rm; do alias "$cmd=command $cmd"; done; unset cmd

## functions

# usage: func() { [minor=1] echo_func; ... }

function echo_func() # usage: [minor=1] "echo_func" "$@" && indent || true

# exit status: whether function call was echoed

{

	log++; if test "$minor"; then log++; fi

	local script="$(canon_rel_path "${BASH_SOURCE[1]}")"

	echo_cmd "$script:${BASH_LINENO[0]}" "${FUNCNAME[1]}" "$@"

	can_log

}

alias echo_func='"echo_func" "$@" && indent || true'

## vars

echo_vars() # usage: echo_vars var...

{

	log++; log++

	if can_log; then

		local var

		for var in "${@%%=*}"; do log "$(declare -p "$var")"; done

	fi

}

echo_export() { builtin export "$@"; echo_vars "$@"; }

if test "$verbosity" -ge 2; then

	alias export="echo_export" # automatically echo env vars when they are set

fi

### external command input/output

# usage: cmd1 | { pipe_delay; cmd2; }

alias pipe_delay='sleep 0.1' # s; display after leading output of cmd1

fi # load new aliases

if self_being_included; then

echo_stdin() # usage: input|echo_stdin|cmd

{

	log++

	if can_log; then

		pipe_delay

		echo ----- >&"$log_fd"

		tee -a /dev/fd/"$log_fd";

		echo ----- >&"$log_fd"

	else cat

	fi

}

alias echo_stdout='echo_stdin' # usage: cmd|echo_stdout

fi # load new aliases

if self_being_included; then

#### streams

fd_exists() { (: <&"$1") 2>/dev/null; }

require_fd_not_exists() # usage: require_fd_not_exists fd || return 0

{ ! fd_exists "$1" || type=info die "fd $1 already exists, skipping"; }

set_fd() # usage: dest=fd dir='[<>]' src=fd [noclobber=1] set_fd

{

	echo_func

	: "${dest:?}" "${dir:?}" "${src:?}"

	test ! "$noclobber" || require_fd_not_exists "$dest" || return 0

	echo_eval exec "$dest$dir&$src"

}

shadow_fd() # usage: prefix=# src=fd dir='[<>]' shadow_fd

{

	echo_func

	: "${prefix:?}" "${src:?}" "${dir:?}"

	dest="$prefix$src" noclobber=1 set_fd

}

# convention: use fd 10/11/12 for command-specific alternate stdin/stdout/stderr

set_global_fds()

# allows commands to access global stdin/stdout/stderr using fd 20/21/22

# this works even when /dev/tty isn't available

{

	log++; echo_func; log++

	local prefix=2

	# ignore errors if a source fd isn't open

	src=0 dir='<' shadow_fd || true

	src=1 dir='>' shadow_fd || true

	src=2 dir='>' shadow_fd || true

}

set_global_fds

err_fd=22 # global stderr

# usage: explicit_errors_only=1 script...

# show only explicitly-displayed errors (which have been redirected to fd 22)

# most of the time this has the same effect as `verbosity=0 script...`,

# which displays everything that isn't explicitly hidden

# this option should only be used for testing the explicit error displaying

if test "$explicit_errors_only"; then disable_logging; fi

#### functions

func_exists() { declare -f "$1" >/dev/null; }

copy_func() # usage: from=... to=... copy_func

# $to must not exist. to get around the no-clobber restriction, use `unset -f`.

{

	: "${from:?}" "${to:?}"

	func_exists "$from" || die "function does not exist: $from"

	! func_exists "$to" || die "function already exists: $to"

	local from_def="$(declare -f "$from")"

	eval "$to${from_def#$from}"

}

func_override() # usage: func_override old_name__suffix

{ from="${1%%__*}" to="$1" copy_func; }

ensure_nested_func() # usage: func__nested_func() { ensure_nested_func; ... }

{

	local nested_func="${FUNCNAME[1]}"

	local func="${nested_func%%__*}"

	contains "$func" "${FUNCNAME[@]}" || \

		die "$nested_func() must be used by $func()"

}

#### commands

top_script="$(canon_rel_path "$0")" # outermost script

top_dir="$(dirname "$top_script")"

require_not_exists() # usage: require_not_exists file || return 0

{ test ! -e "$1" || type=info die "file "$1" already exists, skipping"; }

# auto-removes a command's output file on error (like make's .DELETE_ON_ERROR)

function to_file() # usage: stdout=... [if_not_exists=1] to_file cmd...

{

	echo_func

	: "${stdout?}"; echo_vars stdout

	test ! "$if_not_exists" || require_not_exists "$stdout" || return 0

	"$@" >"$stdout" || { save_e; log_e; rm "$stdout"; rethrow; }

}

alias to_file='"to_file" ' # last space alias-expands next word

run_args_cmd() # runs the command line args command

{

	test $? -eq 0 || return

	eval set -- "$(reverse "${BASH_ARGV[@]}")"

	test $# -ge 1 || set -- all

	echo_cmd "$top_script" "$@"; "$@"

}

fwd() # usage: subdirs=(...); fwd "$FUNCNAME" "$@"

{

	echo_func

	: "${subdirs?}"

	for subdir in "${subdirs[@]}"; do

		"$(dirname "${BASH_SOURCE[1]}")"/"$subdir"/run "$@"

	done

}

#### URLs

localize_url() { test _"$1" = _"$(hostname -f)" || echo "$1"; }

fi