Exercise 1-17

Exercise 1-17  Write a program to print all input lines that are longer than 80 characters.

#include <stdio.h>

#define MAXLINE 80

int main(void)

{

  int c;

    /* bufpos == MAXLINE means we have filled the buffer and need to print it,

     * bufpos == MAXLINE+1 means we have already printed it. */

  unsigned int bufpos = 0;

  char buffer[MAXLINE];

  while (c=getchar(), c!=EOF)

  {

    if (bufpos<MAXLINE)

    {

      if (c=='\n')

        bufpos = 0;

      else

        buffer[bufpos++]=c;

    }

    else

    {

      if (bufpos==MAXLINE)

      {

        for (bufpos=0; bufpos<MAXLINE;++bufpos)

          putchar(buffer[bufpos]);

        bufpos=MAXLINE+1;

      }

      putchar(c);

      if (c=='\n')

        bufpos = 0;

    }

  }

  return 0;

}