#include<stdio.h>
#include<fcntl.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<signal.h>
#include<stdlib.h>
#include <sys/wait.h>
//the copy fie size must>M
int count=0;
//current copy number
int file_size;
//the file size
pid_t pid;
void sig_alarm(int arg)
{
kill(pid,SIGUSR1);
}
void sig_int(int arg)
{
printf("file size:%d totalreceive size:%dn",file_size,count);
exit(EXIT_SUCCESS);
}
char bar[10000];
void sig_usr(int sig)
{
float i;
strcat(bar,"#");
fflush(stdout);
i=(float)count/(float)file_size;
//printf("curent over :%0.0f%%n",i*100);
printf("curent over :%s %0.0f%%n",bar,i*100);
}
int main(int argc,char *argv[])
{
int i=0,stat_val;;
int fd_src,fd_des;
char buf[4096];
//in order to infirm the problem, buf can set small
if(argc!=3)
{
printf("check the format:comm src_file des_filen");
return -1;
}
if((fd_src=open(argv[1],O_RDONLY) )==-1 )
{
perror("open file src");
exit(EXIT_FAILURE);
}
file_size=lseek(fd_src,0,SEEK_END);
lseek(fd_src,0,SEEK_SET);
if( (fd_des=open(argv[2],O_RDWR|O_CREAT,0644) )==-1 )
{
perror("open fd_fdes");
exit(EXIT_FAILURE);
}
if( (pid=fork())==-1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(pid==0)
{	printf("1pid();%d ppid%dn",getpid(),getppid());
signal(SIGUSR1,sig_usr);
do
{
memset(buf,'',sizeof(buf));
if((i=read(fd_src,buf,sizeof(buf)))==-1)	//the copy number may modify
{
perror("read");
exit(EXIT_FAILURE);
}
else if(i==0)
{
//	perror("kill");
kill(getppid(),SIGINT);
break;
}
else
{
if(write(fd_des,buf,i)==-1)
{
perror("write");
exit(EXIT_FAILURE);
}
count+=i;
}
}while(i!=0);
waitpid(pid,&stat_val,0);
if(WIFEXITED(stat_val))
{
printf("Child exited with code %d count:%dn", WEXITSTATUS(stat_val),count);
}
else if (WIFSIGNALED(stat_val))
{
printf("Child terminated abnormally, signal %d count:%dn", WTERMSIG(stat_val),count);
}
exit(EXIT_SUCCESS);
}
else if(pid>0)
{
signal(SIGALRM,sig_alarm);
signal(SIGINT,sig_int);
#if 0
ualarm(250000,200000);	//if alarm ,in sig_alarm function to install again
#endif
while(1)
{
#if 0
alarm(1);	//if alarm ,in sig_alarm function to install again
pause();
#endif
#if 0
kill(pid,SIGUSR1);
usleep(250000);
#endif
kill(pid,SIGUSR1);
sleep(2);
}
exit(EXIT_SUCCESS);
}
}

2：执行结果