// all.h
// wenxy created in 2005/04/12,AM
// All copyright reserved.

#ifndef _ALL_H
#define _ALL_H

// ANSC C/C++
#include
#include
#include
#include

// linux
#include
#include
#include
#include
#include

// micro define
//#define OutErrStr(info) (printf("Error : %s\n", info))

//#define OutErrInt(info) (printf("Error : %d\n", info))
#define BUFF_SIZE 1024 * 1

#endif

// ----------------------------------------------------------------------------------

// main.c

#include "all.h"

// function
static int ChildProcessFun(void *pParam);

// struct
struct _PROCESS_PARAM
{
#define STR_1 "This is date on pipe."
#define DADA_LEN sizeof(STR_1)
char chBuff[BUFF_SIZE];
int nPipe[2];
pid_t nProcess;
};

int main()
{
printf("Run ...\n");

struct _PROCESS_PARAM ProcessParam;

int nFlag = pipe(ProcessParam.nPipe);
if (nFlag == -1)
{
printf("Error: crrete pipe failed!\n");
printf("------------------------------\n\n");
}
assert(ProcessParam.nPipe[0]);
assert(ProcessParam.nPipe[1]);

// create a child press
ProcessParam.nProcess = fork();
if (ProcessParam.nProcess < 0) /* create process failed */
{
printf("Error: create child process failed!\n");
printf("------------------------------\n\n");
}
else if (ProcessParam.nProcess > 0) /* parent process */
{
printf("\nNote: in parent process ...\n");
printf("New child process ID = %d\n", ProcessParam.nProcess);

// write pipe
close(ProcessParam.nPipe[0]);
write(ProcessParam.nPipe[1], STR_1, strlen(STR_1));
}
else /* child process */
{
if(ChildProcessFun(&ProcessParam) == 0)
{
printf("Child process exit ...\n");
}
else
{
printf("Error: Child process dead lock ...\n");
printf("------------------------------\n\n");
}
}

// close pipe
close(ProcessParam.nPipe[0]);
close(ProcessParam.nPipe[1]);
printf("parent process exit ...\n");
return 0;
}

// child process funtion
static int ChildProcessFun(void *pParam)
{
struct _PROCESS_PARAM ProcessParam = \
(struct _PROCESS_PARAM) \
*(struct _PROCESS_PARAM *)pParam;

printf("Note: in child process ...\n");
printf("The child process ID = %d\n", ProcessParam.nProcess);

// read pipe
close(ProcessParam.nPipe[1]);
read(ProcessParam.nPipe[0], ProcessParam.chBuff, DADA_LEN);
ProcessParam.chBuff[DADA_LEN] = '\0'; /* good action */
printf("Read the pipe data: %s\n", ProcessParam.chBuff);
printf("*********************************\n\n");
return 0;
}

/* end main.c ******************************************************* */

// -----------------------------------------------------------------------------------------------

# makefile

objets = main.o
rubbish = $(objets) main

main : main.o
g++ -o main main.o

main.o : main.c all.h
g++ -c main.c

.PHONY : clean
clean :
-rm $(rubbish)

# end makefile