linux 文件内容的复制

#include <string.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
#define BUFFER_SIZE 1024 

int main(int argc,char **argv) 
{ 
	FILE *from_fd;
	FILE *to_fd; 
	long file_len=0;
	char buffer[BUFFER_SIZE]; 
	char *ptr; 
	
	/*判断入参*/
	if(argc!=3) 
	{ 
		printf("Usage:%s fromfile tofile
",argv[0]); 
		exit(1); 
	} 

/* 打开源文件 */ 
if((from_fd=fopen(argv[1],"rb"))==NULL) 
{ 
	printf("Open %s Error
",argv[1]); 
	exit(1); 
} 

/* 创建目的文件 */ 
if((to_fd=fopen(argv[2],"wb"))==NULL) 
{ 
	printf("Open %s Error
",argv[2]); 
	exit(1); 
} 

/*测得文件大小*/
fseek(from_fd,0L,SEEK_END);
file_len=ftell(from_fd);
fseek(from_fd,0L,SEEK_SET);
printf("from file size is=%d
",file_len);

/*进行文件拷贝*/
while(!feof(from_fd)) 
{ 
	fread(buffer,BUFFER_SIZE,1,from_fd);
	if(BUFFER_SIZE>=file_len)
	{
		fwrite(buffer,file_len,1,to_fd);
	}
	else 
	{
		fwrite(buffer,BUFFER_SIZE,1,to_fd);
		file_len=file_len-BUFFER_SIZE;
	}
	bzero(buffer,BUFFER_SIZE);
} 
fclose(from_fd); 
fclose(to_fd); 
exit(0); 
}