linux c 获取指定进程 父进程pid

示例如下：

int GetFatherPid(int pid){char dir[1024]={0};char path[1024] = {0};char buf[1024] = {0};int rpid = 0;int fpid=0;char fpth[1024]={0};struct stat st;ssize_t ret =0;sprintf(dir,"/proc/%d/",pid);sprintf(path,"%sstat",dir);if(stat(path,&st)!=0){return -2; }memset(buf,0,strlen(buf));FILE * fp = fopen(path,"r");ret += fread(buf + ret,1,300-ret,fp);fclose(fp);sscanf(buf,"%*d %*c%s %*c %d %*s",fpth,&fpid);fpth[strlen(fpth)-1]='\0';return rpid;}