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我想叉两个孩子。父母读取发送到管道的行。孩子读它并将其写入另一个管道,最后child2读取它。但是,输出始终是父项。谢谢!C叉两个孩子和父母与子女之间的管道
#define MAX 80
void child();
void parent();
void childtwo();
char * getli();
void printline(char *buffer, int count);
char * convertCase(char *str);
int pipe1[2];
int pipe2[2];
int main(int argc, char **argv)
{
pipe(pipe1);
pipe(pipe2);
if(fork()){
if(fork()){
printf("1st\n");
parent();
exit(0);
}
else{
printf("3rd\n");
childtwo();
exit(0);
}
}
else{
printf("2nd\n");
child();
exit(0);
}
}
void child(){
char *buf;
int count = 0;
close(pipe1[1]);
close(pipe2[0]);
while(1){
buf = (char *) malloc(sizeof(char)*MAX);
read(pipe1[0], buf, MAX);
if (strcmp(buf,"quit")== 0){
printf("Child is leaving\n");
free(buf);
break;
}
else{
printf("Child: ");
printline(buf,strlen(buf));
write(pipe2[1],buf, strlen(buf)+1);
free(buf);
}
close(pipe2[1]);
close(pipe1[0]);
exit(0);
}
}
void childtwo()
{
char *buf;
int count = 0;
close(pipe2[1]);
buf = (char *) malloc(sizeof(char)*MAX);
while(1){
buf = (char *) malloc(sizeof(char)*MAX);
read(pipe2[0], buf, MAX);
if (strcmp(buf,"quit")== 0){
printf("Childtwo is leaving\n");
free(buf);
break;
}
else{
printf("Childtwo:");
printline(buf,strlen(buf));
free(buf);
}
}
close(pipe2[0]);
exit(0);
}
void parent(){
char * buffer;
int count = 0, done=0;
close(pipe1[0]);
while (done != 1){
printf("parent getting line: ");
buffer = getli();
write(pipe1[1],buffer, strlen(buffer)+1);
if (strcmp(buffer,"quit")== 0){
puts("parent goes away");
free(buffer);
break;
}
free(buffer);
}
close(pipe1[1]);
exit(0);
}
你的子进程有内存泄漏,你在循环之前和循环内部分配'buf' _both_。 – 2013-05-05 00:48:45
谢谢指出!但删除它并没有解决问题 – otchkcom 2013-05-05 00:52:38
你是否检查过所有系统调用实际上是_work_?您应该检查他们返回的内容,例如, 'read'返回'-1',那么出现了一些错误,你可以使用例如['perror'](http://en.cppreference.com/w/c/io/perror)打印出错误。您应该为_all_函数执行此操作,即使'fork'可能会失败。 – 2013-05-05 01:07:43