Next: Posix Variants Prev: Compilers and Preprocessors Up: Existing Tests
5.11 System Services
The following macros check for operating system services or
-- Macro: AC_PATH_X
Try to locate the X Window System include files and libraries. If
the user gave the command line options `--x-includes=DIR' and
`--x-libraries=DIR', use those directories.
If either or both were not given, get the missing values by running
`xmkmf' (or an executable pointed to by the `XMKMF' environment
variable) on a trivial `Imakefile' and examining the makefile that
it produces. Setting `XMKMF' to `false' disables this method.
If this method fails to find the X Window System, `configure'
looks for the files 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.
-- Macro: AC_PATH_XTRA
An enhanced version of `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'. Define `X_DISPLAY_MISSING' if X is not available.
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'.
-- Macro: AC_SYS_INTERPRETER
Check whether the system supports starting scripts with a line of
the form `#!/bin/sh' to select the interpreter to use for the
script. After running this macro, shell code in `configure.ac'
can check the shell variable `interpval'; it is set to `yes' if
the system supports `#!', `no' if not.
-- Macro: AC_SYS_LARGEFILE
Arrange for large-file support
some hosts, one must use special compiler options to build
programs that can access large files. Append any such options to
the output variable `CC'. Define `_FILE_OFFSET_BITS' and
`_LARGE_FILES' if necessary.
Large-file support can be disabled by configuring with the
If you use this macro, check that your program works even when
`off_t' is wider than `long int', since this is common when
large-file support is enabled. For example, it is not correct to
print an arbitrary `off_t' value `X' with `printf ("%ld", (long
The LFS introduced the `fseeko' and `ftello' functions to replace
their C counterparts `fseek' and `ftell' that do not use `off_t'.
Take care to use `AC_FUNC_FSEEKO' to make their prototypes
available when using them and large-file support is enabled.
-- Macro: AC_SYS_LONG_FILE_NAMES
If the system supports file names longer than 14 characters, define
-- Macro: AC_SYS_POSIX_TERMIOS
Check to see if the Posix termios headers and functions are
available on the system. If so, set the shell variable
`ac_cv_sys_posix_termios' to `yes'. If not, set the variable to
automatically generated by info2www