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

if test ! "$_util_sh_include_guard_utils"; then

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

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

shopt -s expand_aliases

#### vars

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

alias local_export='declare -x' # combines effects of local and export

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

#### aliases

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

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

#### functions

kw_params() # usage: func() { kw_params param_var...; }; ...; param_var=... cmd

# removes keyword-param-only vars from the environment

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"'

fi # load new aliases

# 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'

fi # load new aliases

#### 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 result= n="$n" # n will be modified in function

}

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

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

#### arrays

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

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

{

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

}

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

#### verbose output

err_fd=2 # stderr

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

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=1}" # default

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

export verbosity # propagate to invoked commands

# definition: the log_level is the minimum verbosity needed to display a message

# to view a message's log_level, count the # of + signs before it in the output

alias PS4_prefix_n='str="${PS4:0:1}" n=$1 repeat'

# usage: in func:      log++; ...         OR  log_local; "log++"; ...

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

#        before cmd:   log++ cmd...

# without a cmd, "$@" expands to nothing and assignments are applied to caller

# "${@:2}" expands to all of $@ after *1st* arg, not 2nd ($@ indexes start at 1)

alias log_local='declare PS4="$PS4" verbosity="$verbosity"'

alias log+='log_local; "log+" ' # last space alias-expands next word

alias log++='log_local; "log++" ' # last space alias-expands next word

fi # load new aliases

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; }

log_custom() # usage: symbol=... log_custom msg

{ log_indent="${log_indent//[^ ]/$symbol}" PS4="${PS4//[^ ]/$symbol}" log "$@";}

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

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

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

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

#### functions

#### paths

rel_path() # usage: base_dir=... path=... rel_path

{

	log++; kw_params base_dir path

	local path="$path/" # add *extra* / to match path when exactly = base_dir

	if test ! "$path"; then path=.; fi # ensure non-empty

	echo_vars path

	echo "$path"

cd -P . # expand symlinks in $PWD so it matches the output of realpath

canon_rel_path() { base_dir="$PWD" path="$(realpath "$1")" rel_path; }

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

### command echoing

fi # load new aliases

echo_cmd() { echo_params; }

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

## vars

## functions

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

fi # load new aliases

#### streams

setup_log_fd() # view logging output at verbosity >= 5

set_global_fds()

# view logging output at verbosity >= 3

{

#### paths

top_script_abs="$(realpath "$0")"; echo_vars top_script_abs # outermost script

set_paths()

	top_script="$(canon_rel_path "$top_script_abs")"; echo_vars top_script

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

## internal commands

.()

	cmd2rel_path; set -- "$FUNCNAME" "$@"

	(log++; echo_params; can_log) && indent || true

	builtin "$@"

cd() # indent is permanent within subshell cd was used in

	cmd2rel_path; echo_cmd "$FUNCNAME" "$@"

	can_log && caller_indent || true

	# -P: expand symlinks so $PWD matches the output of realpath

	builtin "$FUNCNAME" -P "$@"

	set_paths

}

## external commands

disable_logging() { set_fds "$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...

{

	kw_params cmd_log_fd

	# if no cmd_log_fd, limit log_fd in case command uses util.sh

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

	(

		# the following redirections must happen in exactly this order

		if test "$cmd_log_fd"; then command__set_fds; fi

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

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

	) || return

}

function command__set_fds()

	if can_log; then

	set_fds "$cmd_log_fd>$src"

}

# auto-echo common external commands

pipe_delay () # usage: cmd1 | { pipe_delay; cmd2; }

echo_stdin() # usage: input|echo_stdin|cmd

{

	log++

	if can_log; then

		pipe_delay

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

	else cat

}

echo_stdout () { echo_stdin; } # usage: cmd|echo_stdout

#### commands

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

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

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

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

{

	echo_func; kw_params stdout

	: "${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

{

	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 "${subdirs[@]}"; do "$top_dir"/"$subdir"/run "$@"; done

}

#### URLs

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

fi