Datasheet

540
Exploring the Software-Development Tools in Linux
Table 1-2 (continued)
Variable Meaning
$?
Names of all dependent files (with spaces between the names)
that are newer than the target.
$@ Complete name of the target. If the target is libDisp.a
image.o), for example, $@ is libDisp.a.
$^
Names of all dependent files, with spaces between the names.
Duplicates are removed from the dependent filenames.
AR Name of the archive-maintaining program (default value: ar).
ARFLAGS Flags for the archive-maintaining program (default value: rv).
AS
Name of the assembler program that converts the assembly lan-
guage to object code (default value: as).
ASFLAGS
Flags for the assembler.
CC Name of the C compiler (default value: cc).
CFLAGS
Flags that are passed to the C compiler.
CO
Name of the program that extracts a file from RCS (the default
value is co).
COFLAGS Flags for the RCS co program.
CPP Name of the C preprocessor (default value: $(CC) -E).
CPPFLAGS
Flags for the C preprocessor.
CXX Name of the C++ compiler (default value: g++).
CXXFLAGS
Flags that are passed to the C++ compiler.
FC Name of the FORTRAN compiler (default value: f77).
FFLAGS
Flags for the FORTRAN compiler.
LDFLAGS Flags for the compiler when it’s supposed to invoke the linker ld.
RM Name of the command to delete a file (Default value: rm -f).
A sample makefile
You can write a makefile easily if you use the predefined variables of GNU
make and its built-in rules. Consider, for example, a makefile that creates
the executable xdraw from three C source files (xdraw.c, xviewobj.c, and
shapes.c) and two header files (xdraw.h and shapes.h). Assume that
each source file includes one of the header files. Given these facts, here is
what a sample makefile may look like:
42_770191-bk08ch01.indd 54042_770191-bk08ch01.indd 540 8/6/10 9:51 AM8/6/10 9:51 AM