#### streams

stdout2fd() # usage: fd=# stdout2fd cmd...

{

	echo_func; kw_params fd; : "${fd?}"

	if test "$fd" != 1; then local redirs=(">&$fd" "${redirs[@]}"); fi

	redir "$@"

}

function filter_fd() # usage: (fd=# [redirs=] filter_fd filter_cmd...; \

# with filter...) # be sure ${redirs[@]} is not set to an outer value

# useful e.g. to filter logging output or highlight errors

{

	echo_func; kw_params fd; : "${fd?}"

	set_fds "$fd>" >(pipe_delay; stdout2fd "$@")

	pipe_delay; pipe_delay # wait for >()'s pipe_delay and initial logging

}

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

stderr2stdout() # usage: { stderr2stdout cmd...|use stderr...; } 41>&1

# **IMPORTANT**: fd 41 must later be redirected back to fd 1

# unlike `2>&1`, logs stderr

# redirects the command stdout to fd 41 to avoid collision with stderr

{

	echo_func

	# command causes log_fd to be re-filtered, so that stderr is also filtered.

	# fd 2 is *not* redirected back to fd 2, to allow log-filtering out an

	# otherwise-confusing benign error.

	"$@" 2> >(log++ command tee /dev/fd/"$log_fd") >&41 #redirects 2->{1,log_fd}

}

stdout_contains()

# usage: { stderr2stdout cmd|stdout_contains echo_run grep ...; } 41>&1

{

	log_local; log++; echo_func

	pipe_delay; pipe_delay; pipe_delay; "$@"|echo_stdout >/dev/null

}

stderr_matches() # usage: pattern=... [ignore_e=#] stderr_matches cmd...

{

	echo_func; kw_params pattern ignore_e; : "${pattern?}"

	if test "$ignore_e"; then local benign_error=1; fi

	# not necessary to allow callers to handle the error themselves (which would

	# require *every* caller to wrap this function in prep_try/rethrow), because

	# they would just handle it by errexiting anyways

	prep_try

	set +o errexit # avoid errexiting since @PIPESTATUS will be used instead

	{ stderr2stdout "$@"|stdout_contains echo_run grep -E "$pattern"; } 41>&1

	local PIPESTATUS_=("${PIPESTATUS[@]}") # save b/c it's reset after each cmd

	set -o errexit

	# handle any error

	e="${PIPESTATUS_[0]}" # 1st command's exit status -> $e

	local matches="$(errexit "${PIPESTATUS_[1]}"; exit2bool)"

	if test "$matches"; then ignore_e "$ignore_e"; fi #also works w/ ignore_e=''

	rethrow_exit #force-exit b/c caller's test of return status disables errexit

	return "${PIPESTATUS_[1]}" # 2nd command's exit status -> $?

}

fi # load new aliases

if self_being_included; then

function ignore_err_msg() # usage: pattern=... [ignore_e=#] ignore_err_msg cmd

# unlike `|| true`, this suppresses only errors caused by a particular error

# *message*, rather than all error exit statuses

{

	echo_func; kw_params pattern; : "${pattern?}"

	stderr_matches "$@" || true # also ignore false exit status on no match

}

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