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

#define LINE_LENGTH  80
#define PAT_LENGTH  32

typedef enum {FALSE, TRUE} Bool_t;

Bool_t IsSubstringOf(char pat[], char text[])
/* Returns TRUE iff pat is a substring of text. */
{
   int i = 0, j;

   while (text[i] != '\0') {
      j = 0;
      while (pat[j] != '\0' && text[i+j] != '\0' && pat[j] == text[i+j]) {
         ++j;
      }
      if (pat[j] == '\0') {
         return TRUE;
      }
      ++i;
   }
   return FALSE;
}

void PutLine(char line[])
/* Writes "line" to the output. */
{
   int i =0;

   while (line[i] != '\0') {
      putchar(line[i]);
      ++i;
   }
   putchar('\n');
}

Bool_t GetLine(char line[], int length)
/* Reads one line of the input into "line", 
   truncating to "length" (including final '\0').
   Returns TRUE iff EOF is encountered immediately. */ 
{
   int i = 0, c = getchar();

   if (c == EOF) {
      return TRUE;
   }
   while (c != '\n' && c != EOF) {
      if (i < length - 1) {
         line[i] = c;
         ++i;
      }
      c = getchar();
   }
   line[i] = '\0';
   return FALSE;
}

void Grep (void)
/* Reads first line of the input into "pat".  
   Reads remainder of the input, line by line,
   copying each line to the output 
   iff it contains "pat". */
{
   char line[LINE_LENGTH], pat[PAT_LENGTH];

   GetLine(pat, PAT_LENGTH);
   while (!GetLine(line, LINE_LENGTH)) {
      if (IsSubstringOf(pat, line)) {
         PutLine(line);
      }
   }
}

int main (void)
{
   Grep();   
   PutLine("\n\n *** Bye! ***");
   return EXIT_SUCCESS;
}