想在两个程序间通信，但管道的数据会一直结尾追加，不能清空从头开始发数据，求大佬！
读端：
int main(){
char *filename = "/home/hi/testprog/my_fifo";
int fd;
char buf_r[100];
int nread;
int i = 0;
fd = open(filename,O_RDONLY);
if(fd == -1){
printf("open file fail!!\n");
return 0;
}
printf("hello , start to test reading!!!\n");
while(1)
{
memset(buf_r,0x00,sizeof(buf_r));
if((nread = read(fd, buf_r, 100)) == -1)
{
printf("从FIFO读取的数据为：%s\n", buf_r);
for(i;i<20;i++){
printf("%d",buf_r[i]);
}
i = 0;
fflush(stdout);
sleep(1);
}
return 0;
}
写端：
int main(){
char *c;
char *str;
str = malloc(100*sizeof(char*));
c = malloc(100*sizeof(char*));
char *filename = "/home/hi/testprog/my_fifo";
int res = mkfifo(filename,0777);
int fd;
if(res != 0){
fprintf(stderr,"fifo creat file fail!!\n");
exit(EXIT_FAILURE);
}
fd = open(filename,O_WRONLY);
if(fd == -1){
printf("open file fail!!\n");
return 0;
}
printf("hello , start test to writing!!!\n");
while(1)
{
fflush(stdout);
while((*c = getchar()) != '\n'){
strcat(str,c);
}
write(fd,str,100);
printf("end of write!\n");
sleep(1);
}
return 0;
}