AmiWest Lesson 2

AmiWest Lesson 2: Fundamentals

Basic Types

It is important to under at least the basic types when programming. The following table summarizes the basic types used in AmigaOS as compared to standard C and C++ types:

AmigaOS Types

Type	Deprecated Type(s)	C	C++
uint64	none	uint64_t	uint64_t
int64	none	int64_t	int64_t
uint32	ULONG or LONGBITS or CPTR	uint32_t	uint32_t
int32	LONG	int32_t	int32_t
uint16	UWORD or WORDBITS or USHORT or UCOUNT or RPTR	uint16_t	uint16_t
int16	WORD or SHORT or COUNT	int16_t	int16_t
uint8	UBYTE or BYTEBITS	char or unsigned char	unsigned char
int8	BYTE	signed char	signed char
STRPTR	none	char*	char*
CONST STRPTR	n/a	char* const x	char* const x
CONST_STRPTR	n/a	const char*	const char*
CONST CONST_STRPTR	n/a	const char* const	const char* const
APTR	none	void*	void*
CONST APTR	none	void* const x	void* const x
CONST_APTR	none	const void*	const void*
CONST CONST_APTR	none	const void* const	const void* const
float32	FLOAT	float	float
float64	DOUBLE	double	double
BOOL	none	int16	int16
TEXT	none	char	char
NULL	none	0L	(void*)0L
BPTR	none	int32_t	int32_t
BSTR	none	int32_t	int32_t
ZERO	none	(BPTR)0	(BPTR)0

Static versus Dynamic Linking

The different between static and dynamic linking can best be explained with an example.

#include <stdio.h>
 
int main()
{
 printf("Hello, world\n");
 return 0;
}

Here is "hello" created using static linking:

gcc -mcrt=clib2 -o hello hello.c -Wl,--cref,-M,-Map=hello.map

The "hello" executable is roughly 86906 bytes in size. The "hello.map" file contains the linker map which shows you exactly what pieces of code have been pulled in from where to create that executable.

Here is "hello" created using dynamic linking:

gcc -mcrt=newlib -o hello hello.c -Wl,--cref,-M,-Map=hello.map

Tasks and Processes

Code to display Tasks and Processes.