function extern () { (unset -f "$1"; "$@") || exit; }

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

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

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

	alias self_being_included=false

}

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

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

shopt -s expand_aliases

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

#### exceptions

alias try='declare e; try_ ' # trailing space alias-expands next word

alias end_try_subshell='exit "$e"'

#### integers

#### arrays

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

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

#### verbose output

# usage: (stdout2stderr; cmd...) || exit

: "${verbosity:=$verbose}" "${verbosity:=0}"

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

: "${log_indent='  '}"

# usage: in func:      inc_log_level; ...

alias inc_log_level='declare verbosity="$verbosity" PS4="$log_indent$PS4"

# usage: (log_stderr; cmd...) || exit

log_stderr_cmd () # usage: [stdout2stderr=1] log_stderr_cmd cmd...

echo_cmd () { if can_log; then echo "$PS4$*" >&2; fi; }

echo_run () { echo_cmd "$@"; "$@"; }

alias echo_run_extern='echo_run log_stderr_cmd "extern"'

alias extern="echo_run_extern" # automatically echo external commands

# commands that are always external

canon_rel_path ()

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

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

	echo "$path"

fi # load new aliases

if self_being_included; then

function echo_func ()

{

	inc_log_level

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

}

echo_stdin () # usage: input|echo_stdin|cmd

	inc_log_level

	if can_log; then

}

echo_vars () # usage: echo_vars var...

{

	builtin export "$@"

	echo_vars "$@"

if test "$verbosity" -ge 2; then

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

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

fi # load new aliases

#### strings

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

#### vars

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

# usage: local var=...; local_inv

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

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

#### commands

top_dir="$(dirname "$0")" # outermost script

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 "$(canon_rel_path "$0")" "$@"; "$@"

}

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

{

	echo_func

	: "${subdirs?}"

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

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

	done

#### make

# usage: target_filename/command () { echo_func; set_make_vars; ...; }

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

make ()

	echo_func

	stdout2stderr=1 extern make --directory="$top_dir" "$@"

}

if false; then ## usage:

inline_make 3<<'EOF'

target:

	echo_func

	local self="$(readlink -f "${BASH_SOURCE[1]}")"

	export self self_dir

	make --makefile=<((

		cat /dev/fd/3

		echo -n "

.SUFFIXES: # turn off built-in suffix rules

"

}

#### compression

zip ()

	stdout2stderr=1 try extern zip "$@"

	ignore 12 # "zip has nothing to do" (`man zip`)

unzip () { stdout2stderr=1 extern unzip "$@"; }

set_inv force

#### databases

# using prefixed connection vars

alias use_local="declare prefix=local_; import_vars"

alias use_local_remote="use_local; use_remote"

quote='"'

alias mk_schema_esc="declare schema_esc; mk_esc_name schema"

# auto-adds connection/login opts when specified

mysql_cmd () # usage: mysql* () { ...; mysql_cmd "$@"; }

{

	echo_func

	if test _"$ssh_server" = _"$(hostname -f)"; then local ssh_server=; fi

	if test -n "$ssh_server"; then

	if test -n "$schema"; then local database="${database-$schema}"; fi

	local var=ssh_dest; local_inv

	extern ${ssh_dest:+ssh "$ssh_dest" }"${FUNCNAME[1]}" \

${server:+ --host="$server" }${user:+--user="$user" } --password\

}

mysql ()

	echo_func

	mysql_cmd --verbose "$@"

}

	echo_func

	(echo "SET sql_mode = 'ANSI';"; cat)|mysql "$@"

mysqldump () # usage: [schema=1 | data=1] mysqldump db [table...]

	echo_func

	mysql_cmd --quick --lock-tables=false --set-charset \

mysqldump_diffable ()

	echo_func

	mysqldump "$@"|sed 's/^(-- Dump completed).*$/\1/'

### PostgreSQL

	echo_func

	if test -z "$source"; then

		if test -z "$limit"; then local source="$table_esc"

		fi

	local pg_copy_format="${pg_copy_format-CSV HEADER}"

	psql "$@" <<<"COPY $source TO STDOUT $pg_copy_format;"

}

	echo_func

	local pg_copy_format="CSV HEADER" limit=0

	pg_copy_to "$@"|echo_stdin

}

	echo_func

	local pg_copy_format="CSV"

	pg_copy_to "$@"

}

	echo_func

	local table="$1"; shift; mk_table_esc

	local cols="$(pg_header)"

	pg_export_table_no_header "$@" >"$exports_dir/$table.no_header.cols=$cols.csv"

fi