configure: Check for -ltermcap and term.h

This patch adds clever detection for a -ltermcap capable library, which
can be any of: libtermcap, libtinfo, libcurses, or libncurses.  It also
checks for term.h, not termcap.h, because we like cookies.

Configure is clever in that it adds the found library to $LIBS, which is
what mg is later linked with, along with $(lite_LIBS) which pkg-config
provides us with.  So, this patch also remove -ltermcap from mg_LDADD,
since anything that has tgoto() will do.

Signed-off-by: Joachim Nilsson <[email protected]>

Makefile.am

@@ -14,7 +14,7 @@ mg_CFLAGS      += -fomit-frame-pointer -fdata-sections -ffunction-sections	\
 		  -Wl,--gc-sections -Wl,-z,norelro -Wl,--hash-style=gnu		\
 		  -Wl,--build-id=none
 endif
-mg_LDADD        = -ltermcap $(lite_LIBS)
+mg_LDADD        = $(lite_LIBS)
 dist_man1_MANS  = mg.1
 doc_DATA        = README
 EXTRA_DIST      = tutorial

configure.ac

@@ -12,6 +12,20 @@ AC_HEADER_STDC
 # Check for required libraries
 PKG_CHECK_MODULES([lite], [libite >= 1.6.0])
 
+# Check for a termcap compatible library
+AC_CHECK_LIB(termcap, tgoto, , [
+	AC_CHECK_LIB(tinfo, tgoto, , [
+		AC_CHECK_LIB(curses, tgoto, , [
+			AC_CHECK_LIB(ncurses, tgoto, , [
+				AC_MSG_ERROR([Cannot find a termcap capable library, try installing Ncurses.])])
+			])
+		])
+	])
+
+# We want term.h, not termcap.h, because cookies ...
+AC_CHECK_HEADERS(term.h, , [
+	AC_MSG_ERROR([Cannot find required header file term.h, try installing Ncurses.])])
+
 # Check for configured features
 AC_ARG_ENABLE(regexp, AS_HELP_STRING([--enable-regexp],  [Enable full regexp search]))
 AC_ARG_ENABLE(size-optimizations,