# include <stdio.h>
# include <string.h>
# include <ctype.h>

# define BUFSIZE	8192
# define NILSTR		((char *) 0)
# define tfprintf	if (isatty(0)&&isatty(1)&&isatty(2)) fprintf
# define TXTFILE	"/var2/nserve/db/user.dat.new"

static char *usage = "Usage: (without arguments)\n";
void lowerstr ();

main (argc, argv)
  int argc;
  char **argv;
{
  char *me;
  register char *l,		/* ptr to current character in current line */
				*s,		/* ptr to current character in search string */
				*sl;	/* ptr to start of matched search string */
  char *starg;
  char *token;
  char *mail;
  char *id;
  char *alias;
  char *passwd;
  char match, linematch;
  FILE *sf, *mp;
  char sstring [BUFSIZE];
  char line [BUFSIZE];
  char mcmd [BUFSIZE];
  char outb [4 * BUFSIZE];
  int  length;

  /* get my basename */
  me = strrchr (argv [0], '/');
  me = (me)? me + 1 : argv [0];

  setuid (geteuid ());

  if (argc != 1) {
	tfprintf (stderr, usage, me);
	exit (1);
  }

  if (!(sf = fopen (TXTFILE, "r"))) {
	exit (2);
  }

  match = '\0';
  while (1) {
	fgets (sstring, BUFSIZE, stdin);
	if (feof (stdin)) {
	  exit (6);
	}
	if (match) {
	  break;
	}
	else if (!strcmp (sstring, "\n")) {
	  match = '\1';
	}
  }
  length = strlen (sstring);
  if (!length) {
	exit (6);
  }
  else {
	sstring [length - 1] = '\0';
  }

  if (strlen (sstring) != strcspn (sstring, "0123456789")) {
	tfprintf (stderr, "%s: cannot lookup numbers.\n", me);
	exit (3);
  }
  
  lowerstr (sstring);
  linematch = '\0';

  while (1) {
	fgets (line, BUFSIZE - 1, sf);
	length = strlen (line);
	if (length) {
	  line [length - 1] = '\0';
	}
	if (feof (sf)) {
	  break;
	}

	lowerstr (line);
	starg = &line [0];
	match = '\0';
	mail = id = alias = passwd = NILSTR;

	while (token = strtok (starg, "\t")) {
	  starg = NILSTR;					/* for next call to strtok */
	  for (l = token, s = &sstring[0] ; *l; l++) {

		/* search for a match in search string */
		if (*s == *l) {				/* if characters match... */
		  if (s == &sstring[0] && !match) {	/* save cur. pos. */
			sl = l;
		  }
		  if (! *(++s)) {				/* and search string is over... */
			match ='\1';
		  }
		}
		else {
		  s = &sstring[0];			/* otherwise, re-initialize ptr to search */
		}

		/* search for a match in 2: and 5: fields */
		if (l == token + 2) {
		  if (*(l - 2) == '2' && *(l - 1) == ':') {
			mail = l;
		  }
		  if (*(l - 2) == '5' && *(l - 1) == ':') {
			id = l;
		  }
		  if (*(l - 2) == '6' && *(l - 1) == ':') {
			alias = l;
		  }
		  if (*(l - 2) == '7' && *(l - 1) == ':') {
			passwd = l;
		  }
		}

	  } /* for */
	} /* while */

	/* check for a duplicate match */
	if (linematch && match) {
	  tfprintf (stderr, "multiple matches\n");
	  exit (4);
	}
	else if (match) {
	  linematch = match;
	  sprintf (mcmd, "/usr/ucb/mail -s \"Your name server id\" %s", mail);
	  if (passwd) {
		sprintf (mcmd, "/usr/ucb/mail -s \"Illegal request\" avarvit@cc.ece.ntua.gr",mail);
		sprintf (outb, "\nA request was made for disclosure of the name server identity code\nfor the entries matching the search string \"%s\".\n\nA single match was found, which corresponds to the e-mail address below.\n\n\t %s\n\nSince this entry already has a password, this request is illegal.\nPlease investigate this by contacting \"%s\" personally.\n\nThank you.\n",
	    sstring, mail, alias);
	  }
	  else if (mail) {
		sprintf (outb, "\nA request was made for disclosure of the name server identity code\nfor the entries matching the search string \"%s\".\n\nA single match was found, which corresponds to your e-mail address.\n\nYour id code is: %s\n\nPlease use this id string as soon as possible as a password for logging\ninto the name server and setup an initial \"real\" password. As soon as\nyou do so, your id cannot serve as a password anymore. In order to do\nthis, connect to the name server via \"ph\", issue the command\n\n\tlogin %s\n\nand supply your id code as a password. Afterwads, issue the command\n\n\tpassword\n\nto setup a new password.\n\nPlease contact staff@cc.ece.ntua.gr for any problems you may have.\n\nThank you.\n",
	    sstring, id, alias);
	  }
	  else {
		tfprintf (stderr, "This user does not have an e-mail registered.\n");
		exit (5);
	  }
	  /* matched: %s, mail=%s, id=%s\n", sl, mail, id); */
	}

  } /* while */

  if (linematch) {
	if (!(mp = popen (mcmd, "w"))) {
	  exit (7);
	}
	fprintf (mp, outb);
	pclose (mp);
	close (sf);
	exit (0);
  }
  else {
	tfprintf (stderr, "Not found.\n");
	exit (6);
  }
}

void lowerstr (s)
  register char *s;
{
  while (*s) {
	if (isupper (*s)) {
	  *s = tolower (*s);
	}
	s++;
  }
}