event_attr_confvar.c

Go to the documentation of this file.

/*
** Copyright (C) 2005 by Kevin L. Mitchell <klmitch@mit.edu>
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
**
** @(#)$Id: event_attr_confvar.c,v 1.1 2005/06/04 17:57:03 klmitch Exp $
*/
#include "event_int.h"

#include <stdlib.h>
#include <string.h>

RCSTAG("@(#)$Id: event_attr_confvar.c,v 1.1 2005/06/04 17:57:03 klmitch Exp $");

ev_err_t
event_attr_confvar(ev_attr_t *attr, const char *name, const char *value)
{
  int cmp;
  ev_overvars_t **ptr, *tmp;

  ev_init(); /* initialize library... */

  if (!ea_verify(attr) || !name) /* must be a valid attr */
    ev_return(EINVAL);

  /* Now, walk the linked list, looking for a variable match and ordering */
  for (ptr = &(ea_ovars(attr)); *ptr; ptr = &(*ptr)->ov_next)
    if (!(cmp = strcmp((*ptr)->ov_name, name))) { /* found exact match... */
      /* Change the value of the variable... */
      tmp = *ptr; /* make life easy on ourselves... */

      if (!value) { /* reset to default; just delete this variable */
        if (tmp->ov_next) /* First, clip the thing out of the list... */
          tmp->ov_next->ov_prev_p = tmp->ov_prev_p;
        *tmp->ov_prev_p = tmp->ov_next;

        free(tmp); /* then release the memory */
      } else if (strcmp(tmp->ov_value, value)) /* if values differ... */
        tmp->ov_value = value; /* just set the new value */

      ev_return(0); /* all done! */
    } else if (cmp > 0) /* this entry is larger than what we're inserting */
      break; /* so break out of the loop and we'll insert before it */

  if (!value) /* an order to reset to defaults.  Yeah, right. */
    ev_return(0); /* don't bother :) */

  /* OK, now let's allocate a varlist element and initialize it... */
  if (!(tmp = (ev_overvars_t *)malloc(sizeof(ev_overvars_t))))
    ev_return(ENOMEM);

  /* Now, let's initialize it for its new place in the list... */
  tmp->ov_next = *ptr;
  tmp->ov_prev_p = ptr;
  tmp->ov_name = name;
  tmp->ov_value = value;

  /* And, finally, insert it into the list */
  *ptr = tmp;

  ev_return(0);
}

---