Add support for BINDIR, fix default MANDIR, use LDADD vars

I avoided defaulting MANDIR to /usr/local/man because I thought it
didn't work on GNU/Linux and users would be confused, but it turns
out man-db's default configuration includes both /usr/local/man and
/usr/man, so ${PREFIX}/man is a sensical default.

Makefile

@@ -1,12 +1,16 @@
 PREFIX ?= /usr/local
-MANDIR ?= ${PREFIX}/share/man
+BINDIR ?= ${PREFIX}/bin
+MANDIR ?= ${PREFIX}/man
 
 CEXTS = gnu-case-range gnu-conditional-omitted-operand
 CFLAGS += -std=c11 -Wall -Wextra -Wpedantic ${CEXTS:%=-Wno-%}
-LDLIBS = -lncursesw -ltls
+LDADD.libtls = -ltls
+LDADD.ncursesw = -lncursesw
 
 -include config.mk
 
+LDLIBS = ${LDADD.libtls} ${LDADD.ncursesw}
+
 OBJS += buffer.o
 OBJS += chat.o
 OBJS += command.o
@@ -30,30 +34,30 @@ catgirl: ${OBJS}
 
 ${OBJS}: chat.h
 
-tags: *.h *.c
-	ctags -w *.h *.c
+tags: *.[ch]
+	ctags -w *.[ch]
 
 clean:
-	rm -f tags catgirl ${OBJS}
+	rm -f catgirl ${OBJS} tags
 
 install: catgirl catgirl.1
-	install -d ${DESTDIR}${PREFIX}/bin ${DESTDIR}${MANDIR}/man1
-	install catgirl ${DESTDIR}${PREFIX}/bin
+	install -d ${DESTDIR}${BINDIR} ${DESTDIR}${MANDIR}/man1
+	install catgirl ${DESTDIR}${BINDIR}
 	install -m 644 catgirl.1 ${DESTDIR}${MANDIR}/man1
 
 uninstall:
-	rm -f ${DESTDIR}${PREFIX}/bin/catgirl ${DESTDIR}${MANDIR}/man1/catgirl.1
+	rm -f ${DESTDIR}${BINDIR}/catgirl ${DESTDIR}${MANDIR}/man1/catgirl.1
 
 scripts/sandman: scripts/sandman.o
 	${CC} ${LDFLAGS} scripts/sandman.o -framework Cocoa -o $@
 
 install-sandman: scripts/sandman scripts/sandman.1
-	install -d ${DESTDIR}${PREFIX}/bin ${DESTDIR}${MANDIR}/man1
-	install scripts/sandman ${DESTDIR}${PREFIX}/bin
+	install -d ${DESTDIR}${BINDIR} ${DESTDIR}${MANDIR}/man1
+	install scripts/sandman ${DESTDIR}${BINDIR}
 	install -m 644 scripts/sandman.1 ${DESTDIR}${MANDIR}/man1
 
 uninstall-sandman:
-	rm -f ${DESTDIR}${PREFIX}/bin/sandman ${DESTDIR}${MANDIR}/man1/sandman.1
+	rm -f ${DESTDIR}${BINDIR}/sandman ${DESTDIR}${MANDIR}/man1/sandman.1
 
 CHROOT_USER = chat
 CHROOT_GROUP = ${CHROOT_USER}

configure

@@ -4,27 +4,28 @@ set -eu
 cflags() {
 	echo "CFLAGS += $*"
 }
-ldlibs() {
-	echo "LDLIBS ${o:-}= $*"
-	o=+
-}
-config() {
-	pkg-config --print-errors "$@"
-	cflags $(pkg-config --cflags "$@")
-	ldlibs $(pkg-config --libs "$@")
-}
 defstr() {
 	cflags "-D'$1=\"$2\"'"
 }
 defvar() {
 	defstr "$1" "$(pkg-config --variable=$3 $2)${4:-}"
 }
+ldadd() {
+	lib=$1; shift
+	echo "LDADD.${lib} = $*"
+}
+config() {
+	pkg-config --print-errors "$@"
+	cflags $(pkg-config --cflags "$@")
+	for lib; do ldadd $lib $(pkg-config --libs $lib); done
+}
 
 exec >config.mk
 
 for opt; do
 	case "${opt}" in
 		(--prefix=*) echo "PREFIX = ${opt#*=}" ;;
+		(--bindir=*) echo "BINDIR = ${opt#*=}" ;;
 		(--mandir=*) echo "MANDIR = ${opt#*=}" ;;
 		(*) echo "warning: unsupported option ${opt}" >&2 ;;
 	esac
@@ -32,12 +33,10 @@ done
 
 case "$(uname)" in
 	(FreeBSD)
-		ldlibs -lncursesw
 		config libtls
 		defstr OPENSSL_BIN /usr/bin/openssl
 		;;
 	(OpenBSD)
-		ldlibs -lncursesw -ltls
 		defstr OPENSSL_BIN /usr/bin/openssl
 		;;
 	(Linux)