黄迪明9.1

/*9.1 编写一个程序，把从键盘输入的信息存入指定的文件中去，要求文件名用命令行参数指定。*/

#include<stdio.h>
#include<stdlib.h>

main(int argc, char *argv[])
 {
     FILE *fp;
     char ch;

     if (argc == 1)
         printf("usage:no linenum filename\n");
     else if (argc > 2)
         printf("Too many arguments to linenum\n");
     else if ((fp = fopen(argv[1], "w")) == NULL)
      {
          printf("can't open %s\n", argv[1]);

          return;
      }
     else 
      {
          printf("Input information through keyboard.\n");

          while ((ch = getchar()) != '\n')
              fputc(ch, fp);

           fclose(fp);
      }

     system("pause");
 }