翻译这个C语言程序，没学过指针不太懂

#define MAXLEN 1024  int main(int argc, char *argv[])  {  if( argc < 3 )  {  printf("usage: %s %s/n", argv[0], "infile outfile");  exit(1);  }  FILE * outfile, *infile;  outfile = fopen(argv[2], "wb" );  infile = fopen(argv[1], "rb");  unsigned char buf[MAXLEN];  if( outfile == NULL || infile == NULL )  {  printf("%s, %s",argv[1],"not exit/n");  exit(1);  }   int rc;  while( (rc = fread(buf,sizeof(unsigned char), MAXLEN,infile)) != 0 )  {  fwrite( buf, sizeof( unsigned char ), rc, outfile );  }   fclose(infile);  fclose(outfile);  system("PAUSE");   return 0;  } 1 小时前  浏览 31 次   贪污韩文歌 分享 修改问题 提高悬赏15  收到答案发送短信通知到180******50 1个回答 fastfs  52 分钟前 #define MAXLEN 1024 int main(int argc, char *argv[]) { if( argc < 3 )//输入参数小于2 { printf("usage: %s %s/n", argv[0], "infile outfile"); exit(1); } FILE * outfile, *infile; //打开输出文件 outfile = fopen(argv[2], "wb" ); //打开输入文件 infile = fopen(argv[1], "rb"); unsigned char buf[MAXLEN]; //其中一个打开失败 if( outfile == NULL || infile == NULL ) { printf("%s, %s",argv[1],"not exit/n"); exit(1); } int rc; //读入1字节 while( (rc = fread(buf,sizeof(unsigned char), MAXLEN,infile)) != 0 ) { //写入1字节 fwrite( buf, sizeof( unsigned char ), rc, outfile ); } fclose(infile); fclose(outfile); system("PAUSE"); return 0; }

如果我想打开一个二进制文件并修改里面的内容（比如说加一段）应该怎么修改这个程序，第一次做这个东西