Subject: Techniques for dealing with readline/editline and getopt
To: None <>
From: Johnny C. Lam <>
List: tech-pkg
Date: 05/10/2001 15:37:08
	I've recently had a problem with developing new packages for
the new 7.1.1 release of PostgreSQL.  It can use either libreadline or
libedit, and optionally can use getopt_long() if it's available.  Take
readline for example.  Since -I${LOCALBASE}/include must be passed to
the compiler to pick up some required headers, if readline is
installed, then the PostgreSQL configure script will _always_ use the
readline headers from ${LOCALBASE}/include/readline/readline.h instead
of the ones from /usr/include/readline/readline.h.  It's not right to
force -I/usr/include at the start of the header search list since
private headers may have a name clash with system headers.

	The solution I devised for this was the following Makefile
fragment.  It links the right headers into a known location, which is
then prepended to the header search list.  Does any one have any
thoughts about this?  Perhaps a better way to solve this problem?
I've been thinking about doing something like this on a larger scale
to deal with pkg/10860.


     -- Johnny C. Lam <>
        Department of Statistics, Carnegie Mellon University

.if exists(/usr/include/readline.h)
READLINE_H=		/usr/include/readline.h
HISTORY_H=		/usr/include/history.h
.elif exists(/usr/include/readline/readline.h)
READLINE_H=		/usr/include/readline/readline.h
HISTORY_H=		/usr/include/readline/history.h
READLINE_H=		${LOCALBASE}/readline/readline.h
HISTORY_H=		${LOCALBASE}/readline/history.h
DEPENDS+=		readline>=4.0:../../devel/readline


# This target links the readline and history headers into
# ${WRKINCDIR}/include, which is searched first by the C preprocessor.
	${MKDIR} -p ${WRKINCDIR}/readline
	${RM} -f ${WRKINCDIR}/readline/readline.h
	${RM} -f ${WRKINCDIR}/readline/history.h
	${LN} -sf ${READLINE_H} ${WRKINCDIR}/readline
	${LN} -sf ${HISTORY_H} ${WRKINCDIR}/readline

pre-configure: link-readline-headers