kamcmd: use pkg-config to get compile flags for lib readline

utils/kamcmd/Makefile

@@ -18,6 +18,17 @@ readline_localpath=$(LOCALBASE)/include/readline/readline.h
 readline_locations= /usr/include/readline/readline.h \
 					$(readline_localpath)
 
+ifeq ($(CROSS_COMPILE),)
+	BUILDER = $(shell which pkg-config)
+ifneq ($(BUILDER),)
+	PKGREADLINE = $(shell $(BUILDER) --exists readline > /dev/null 2>&1 ; echo $$? )
+ifneq ($(PKGREADLINE),0)
+	BUILDER =
+endif
+endif
+endif
+
+
 use_readline ?=
 ifneq (,$(MAKECMDGOALS))
 ifeq (,$(filter-out $(nodep_targets),$(MAKECMDGOALS)))
@@ -66,6 +77,12 @@ ifneq (,$(findstring cygwin, $(OS)))
 	LIBS:= -lresolv
 endif
 
+# detect libreadline
+ifneq ($(BUILDER),)
+	DEFS += $(shell $(BUILDER) --cflags readline)
+	LIBS += $(shell $(BUILDER) --libs readline)
+	use_readline := 1
+else
 ifeq ($(use_readline),)
 readline_path := $(shell  \
 						for r in $(readline_locations) ""; do \
@@ -93,14 +110,20 @@ endif
 	LIBS+=-lreadline -lncurses
 endif
 
-endif
+endif  # ifeq ($(use_readline),1)
+
+endif  # ifneq ($(BUILDER),)
 
 
 include $(COREPATH)/Makefile.utils
 
 ifeq (,$(quiet))
 ifeq ($(use_readline),1)
+ifneq ($(BUILDER),)
+$(info readline detected via pkg-config)
+else
 $(info readline detected ($(readline_path)) )
+endif
 $(info command completion enabled)
 else
 $(info "no readline include files detected, disabling readline support")