Working with the Unix OS

Development Tools
$ cc –o pgm main.a filel.o file2.o
cc [options] file.c
-C compile only (suppress link editor)
-g generate code for debugger
-O optimize for speed
-p produce code for profiler
-o name put executable code in name
-M make a makefile
-S generate assembler code .s file
- ld – link editor
Takes one or object files or libraries as input and combines them to produce executable file. It resolves references
to external symbols, and performs "relocation" of addresses.
-lx
search library libx.a
-L dir directory other than /lib or /usr/lib
-u symname enter undefined symbol in symbol table
-S strip symbol table
- cpp -c preprocessor
-Dname=def define name for preprocessor
-Idir
include file directory
-E invoke preprocessor only
Example:
# Example makefile
LIB=~/lib
CFLAGS=-I~/include -DDEBUG
.c.o:
cc -c $(CFLAGS) $<
main: main.a filel.o file2.o
$(CC) -o main filel.o file2.o -L $(LIB)
C Preprocessor
cpp
- actions before c compiler
#define ident token e.g. #define IF if(
#undef ident #define THEN )
#define BEGIN{
#include "filename" #define END }
#include #define ELSE else
used to include:
#defines
externs
typedefs
struct definitions
nested #includes
#if const_expr
#ifdef ident
#ifndef ident
#else
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