usr/src/tools/cscope-fast/history.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1988 AT&T */
  23 /*        All Rights Reserved   */
  24
  25
  26 /*
  27  * Copyright (c) 1999 by Sun Microsystems, Inc.
  28  * All rights reserved.
  29  */
  30
  31 #pragma ident   "%Z%%M% %I%     %E% SMI"
  32
  33 /*
  34  *      cscope - interactive C symbol or text cross-reference
  35  *
  36  *      command history
  37  */
  38
  39 #include <stdio.h>
  40 #include "global.h"
  41
  42 HISTORY *head, *tail, *current;
  43
  44 /* add a cmd to the history list */
  45 void
  46 addcmd(int f, char *s)
  47 {
  48         HISTORY *h;
  49
  50         h = (HISTORY *)mymalloc(sizeof (HISTORY));
  51         if (tail) {
  52                 tail->next = h;
  53                 h->next = 0;
  54                 h->previous = tail;
  55                 tail = h;
  56         } else {
  57                 head = tail = h;
  58                 h->next = h->previous = 0;
  59         }
  60         h->field = f;
  61         h->text = stralloc(s);
  62         current = 0;
  63 }
  64
  65 /* return previous history item */
  66
  67 HISTORY *
  68 prevcmd(void)
  69 {
  70         if (current) {
  71                 if (current->previous)  /* stay on first item */
  72                         return (current = current->previous);
  73                 else
  74                         return (current);
  75         } else if (tail)
  76                 return (current = tail);
  77         else
  78                 return (NULL);
  79 }
  80
  81 /* return next history item */
  82
  83 HISTORY *
  84 nextcmd(void)
  85 {
  86         if (current) {
  87                 if (current->next)      /* stay on first item */
  88                         return (current = current->next);
  89                 else
  90                         return (current);
  91         } else
  92                 return (NULL);
  93 }
  94
  95 /* reset current to tail */
  96
  97 void
  98 resetcmd(void)
  99 {
 100         current = 0;
 101 }
 102
 103 HISTORY *
 104 currentcmd(void)
 105 {
 106         return (current);
 107 }