Click here to download banned.c.

/**************************************************
Write a program that reads a list of banned words
from a file, stores them in an array,  and then
simply reads words from the user and returns
"banned" or "not banned" until the word "end" is
encountered.  The file starts with a number, which
is the number of banned words, and then the words
themselves are listed.
**************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main() {
  // Get name of banned-words file
  char fname[128];
  printf("Banned words file: ");
  fflush(stdout);
  scanf(" %s", fname);

  // Create input file stream
  FILE* fin = fopen(fname, "r");
  if (!fin) {
    printf("ERROR: file not found\n");
    return 1;
  }

  // Read number of words & allocate array
  int numwords;
  fscanf(fin, " %i", &numwords);
  char** bwords = calloc(numwords, sizeof(char*));
  for (int i=0; i < numwords; ++i) {
    bwords[i] = calloc(128, sizeof(char));
  }

  // Read words from file into array
  for(int i=0; i < numwords; ++i) {
    fscanf(fin, " %s", bwords[i]);
  }

  // we can close the file now
  fclose(fin);

  // Get words from user
  char search[128];
  printf("Enter list of words terminated by \"end\".\n");

  scanf(" %s", search);
  while (strcmp(search, "end") != 0) {
    // Look for search in banned list
    int found = 0;
    for (int j=0; j < numwords; ++j) {
      if (strcmp(search, bwords[j]) == 0) {
        found = 1;
        break;
      }
    }

    // Print results
    if (found) {
      printf("%s is banned!\n", search);
    } else {
      printf("%s is not banned.\n", search);
    }

    scanf(" %s", search);
  }

  // clean-up
  for (int i=0; i < numwords; ++i) {
    free(bwords[i]);
  }
  free(bwords);

  return 0;
}