Macro: ac_subst_prefix_subpaths

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# ac_subst_prefix_subpaths

## Synopsis

`AC_DEFINE_SUB_PATH(DEFNAME, varname, description)`

## Version

1.1.1.1 (2001/07/26) guidod @ ac-archive-0.5.32

## Author

## Description

look at varname and detect the subpath that it contains relative to $prefix/$exec_prefix

If the path is indeed relative to $prefix/$exec_prefix, then a single "./" (dotslash) is prepended, otherwise it can be seen as an absolute path that can not be moved, which you possibly do for "/etc" files, or even those ending up in "/lib/modules" or "/winnt/system".

this macro is not very intelligent, it's just a first try in this direction. It does currently just look into the current patterns, and replaces a ${prefix} with a simple dot. Amazingly, it works quite well for most packages.

correct usage: in configure ac `AC_DEFINE_DIR([EPREFIX], [exec_prefix], [--exec-prefix or default])`
`AC_DEFINE_SUB_PATH([PATH_LIBDIR], [libdir], [--bindir subdir])`
`AC_DEFINE_UNQUOTED([PACKAGE],"$PACKAGE", [Name of package])`
in "C" `static const char _libdir[] = PATH_LIBDIR; /* configure default */`
`char* libdir;`
`char* eprefix = getenv (PACKAGE "DIR");`
`if (! eprefix) eprefix = EPREFIX; /* default */`
`if (*_libdir != '.') libdir = strdup(_libdir);`
`else {`
`libdir = malloc(strlen(eprefix) + strlen(_libdir) + 2);`
`strcpy(libdir, eprefix);`
`strcat(libdir, PATH_DELIMITER_STRING);`
`strcat(libdir, _libdir);`
`}`
`...`
`free (libdir);`
``
``
AC_DEFINE_SUB_PATHS(varnames)

look for the given various install-paths that largely depend on either ${prefix} or ${exec_prefix}. Just cut out the prefix and ac_define the value. The value is uppercased and PATH_ prepended ie. ac_define_sub_paths(bindir libdir pkgdatadir) will create the defines PATH_BINDIR PATH_LIBDIR PATH_PKGDATADIR - see posix' include/paths.h that creates _PATH_DEV and friends.

@author: Guido Draheim <guidod@gmx.de> STATUS: never used

## M4 Source Code

    AC_DEFUN([AC_DEFINE_SUB_PATH],
    [dnl
      test "_$prefix" = _NONE && prefix="$ac_default_prefix"
      test "_$exec_prefix" = _NONE && exec_prefix='${prefix}'
      P=`echo ifelse( $2, , [$]$1, [$]$2) | sed -e 's:^\${[a-z_]*prefix}:.:'`
      ifelse ($3, ,
        AC_DEFINE($1, $P, [sub path $2]),
        AC_DEFINE($1, $P, $3))
    ])

    AC_DEFUN([AC_DEFINE_SUB_PATHS],
    [dnl
      test "_$prefix" = _NONE && prefix="$ac_default_prefix"
      test "_$exec_prefix" = _NONE && exec_prefix='${prefix}'
      for i in $1 ; do
      P=`echo \$$i | sed -e 's:^\${[a-z_]*prefix}:.:'`
      V=`echo path_$i | sed -e 'y:abcdefghijklmnopqrstuvwxyz:ABCDEFGHIJKLMNOPQRSTUVWXYZ:'`
        AC_DEFINE($V, $P, [sub path $i]),
    ])