The following macros check for operating system services or capabilities.
configure.in
can check
the variable ac_cv_sys_interpreter
; it will be set to `yes'
if the system supports `#!', `no' if not.
xmkmf
on a
trivial `Imakefile' and examining the `Makefile' that it
produces. If that fails (such as if xmkmf
is not present), look
for them in several directories where they often reside. If either
method is successful, set the shell variables x_includes
and
x_libraries
to their locations, unless they are in directories
the compiler searches by default.
If both methods fail, or the user gave the command line option
`--without-x', set the shell variable no_x
to `yes';
otherwise set it to the empty string.
AC_PATH_X
. It adds the C compiler flags that
X needs to output variable X_CFLAGS
, and the X linker flags to
X_LIBS
. If X is not available, adds `-DX_DISPLAY_MISSING' to
X_CFLAGS
.
This macro also checks for special libraries that some systems need in
order to compile X programs. It adds any that the system needs to
output variable X_EXTRA_LIBS
. And it checks for special X11R6
libraries that need to be linked with before `-lX11', and adds any
found to the output variable X_PRE_LIBS
.
HAVE_LONG_FILE_NAMES
.
HAVE_RESTARTABLE_SYSCALLS
.