C语言文件读写基本操作DEMO

#include <stdio.h>
#include <process.h>
int main()
{
  FILE *infile;
  FILE *outfile;
  //FILE *otherfile;
  char input;
  //char buffer[10];
  int i=0;
  infile=fopen("d:\\infile.txt","r+");  /* r+ 以可读写方式打开文件，该文件必须存在。*/
  /*a+ 以附加方式打开可读写的文件。若文件不存在，则会建立该文件，如果文件存在，*/
  /* 写入的数据会被加到文件尾后，即文件原先的内容会被保留。 （原来的EOF符不保留）*/
  outfile=fopen("d:\\outfile.txt","a+");
  if(!infile)
  {
    fprintf(stderr,"open infile failed...\n");
  }
  if (!outfile)
  {
    fprintf(stderr,"open outfile failed...\n");
  }
  printf("*********************************************\n");
  printf("** This program is to show file operation! **\n");
  printf("** The input file is:                      **\n");
  printf("**                       d:\\infile.txt     **\n");
  printf("** The contents in this file is:           **\n");
  printf("\n");
  for (;;)
  {
    input=fgetc(infile);
    printf("%c",input);
    putc(input,outfile);
    i++;
    
    if (/*input=='\n' || */input ==EOF)
    {
      break;
    }
  }
  printf("\n");
  fclose(infile);
  fclose(outfile);
  system("pause");
  return 0;
}