//: Listmgr.c
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source. 
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com 
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
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// address for non-code errors found in the book.)
/////////////////////////////////////////////////

// Used by NameCollector.java to manage 
// the email list file on the server
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define BSIZE 250

int alreadyInList(FILE* list, char* name) {
  char lbuf[BSIZE];
  // Go to the beginning of the list:
  fseek(list, 0, SEEK_SET);
  // Read each line in the list:
  while(fgets(lbuf, BSIZE, list)) {
    // Strip off the newline:
    char * newline = strchr(lbuf, '\n');
    if(newline != 0) 
      *newline = '\0';
    if(strcmp(lbuf, name) == 0)
      return 1;
  }
  return 0;
}

int main() {
  char buf[BSIZE];
  FILE* list = fopen("emlist.txt", "a+t");
  if(list == 0) {
    perror("could not open emlist.txt");
    exit(1);
  }
  while(1) {
    gets(buf); /* From stdin */
    if(alreadyInList(list, buf)) {
      printf("Already in list: %s", buf);
      fflush(stdout);
    }
    else {
      fseek(list, 0, SEEK_END);
      fprintf(list, "%s\n", buf);
      fflush(list);
      printf("%s added to list", buf);
      fflush(stdout);
    }
  }
} ///:~