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\n",argv[0]);
		exit(1);
	} 

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

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