root/lib/libedit/hist.c
/*      $NetBSD: hist.c,v 1.35 2026/03/03 15:05:17 christos Exp $       */

/*-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Christos Zoulas of Cornell University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "config.h"
#if !defined(lint) && !defined(SCCSID)
#if 0
static char sccsid[] = "@(#)hist.c      8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: hist.c,v 1.35 2026/03/03 15:05:17 christos Exp $");
#endif
#endif /* not lint && not SCCSID */

/*
 * hist.c: History access functions
 */
#include <stdlib.h>
#include <string.h>
#include <vis.h>

#include "el.h"

/* hist_init():
 *      Initialization function.
 */
libedit_private int
hist_init(EditLine *el)
{

        el->el_history.fun = NULL;
        el->el_history.ref = NULL;
        el->el_history.buf = el_calloc(EL_BUFSIZ, sizeof(*el->el_history.buf));
        if (el->el_history.buf == NULL)
                return -1;
        el->el_history.sz  = EL_BUFSIZ;
        el->el_history.last = el->el_history.buf;
        return 0;
}


/* hist_end():
 *      clean up history;
 */
libedit_private void
hist_end(EditLine *el)
{

        el_free(el->el_history.buf);
        el->el_history.buf = NULL;
}


/* hist_set():
 *      Set new history interface
 */
libedit_private int
hist_set(EditLine *el, hist_fun_t fun, void *ptr)
{

        el->el_history.ref = ptr;
        el->el_history.fun = fun;
        return 0;
}


/* hist_get():
 *      Get a history line and update it in the buffer.
 *      eventno tells us the event to get.
 */
libedit_private el_action_t
hist_get(EditLine *el)
{
        const wchar_t *hp;
        int h;
        size_t blen, hlen;

        if (el->el_history.eventno == 0) {      /* if really the current line */
                (void) wcsncpy(el->el_line.buffer, el->el_history.buf,
                    el->el_history.sz);
                el->el_line.lastchar = el->el_line.buffer +
                    (el->el_history.last - el->el_history.buf);

#ifdef KSHVI
                if (el->el_map.type == MAP_VI)
                        el->el_line.cursor = el->el_line.buffer;
                else
#endif /* KSHVI */
                        el->el_line.cursor = el->el_line.lastchar;

                return CC_REFRESH;
        }
        if (el->el_history.ref == NULL)
                return CC_ERROR;

        hp = HIST_FIRST(el);

        if (hp == NULL)
                return CC_ERROR;

        for (h = 1; h < el->el_history.eventno; h++)
                if ((hp = HIST_NEXT(el)) == NULL)
                        goto out;

        hlen = wcslen(hp) + 1;
        blen = (size_t)(el->el_line.limit - el->el_line.buffer);
        if (hlen > blen && !ch_enlargebufs(el, hlen))
                goto out;

        memcpy(el->el_line.buffer, hp, hlen * sizeof(*hp));
        el->el_line.lastchar = el->el_line.buffer + hlen - 1;

        if (el->el_line.lastchar > el->el_line.buffer
            && el->el_line.lastchar[-1] == '\n')
                el->el_line.lastchar--;
        if (el->el_line.lastchar > el->el_line.buffer
            && el->el_line.lastchar[-1] == ' ')
                el->el_line.lastchar--;
#ifdef KSHVI
        if (el->el_map.type == MAP_VI)
                el->el_line.cursor = el->el_line.buffer;
        else
#endif /* KSHVI */
                el->el_line.cursor = el->el_line.lastchar;

        return CC_REFRESH;
out:
        el->el_history.eventno = h;
        return CC_ERROR;

}


/* hist_command()
 *      process a history command
 */
libedit_private int
hist_command(EditLine *el, int argc, const wchar_t **argv)
{
        const wchar_t *str;
        int num;
        HistEventW ev;

        if (el->el_history.ref == NULL)
                return -1;

        if (argc == 1 || wcscmp(argv[1], L"list") == 0) {
                size_t maxlen = 0;
                char *buf = NULL;
                int hno = 1;
                 /* List history entries */

                for (str = HIST_LAST(el); str != NULL; str = HIST_PREV(el)) {
                        char *ptr =
                            ct_encode_string(str, &el->el_scratch);
                        size_t len = strlen(ptr);
                        if (len > 0 && ptr[len - 1] == '\n') 
                                ptr[--len] = '\0';
                        len = len * 4 + 1;
                        if (len >= maxlen) {
                                maxlen = len + 1024;
                                char *nbuf = el_realloc(buf, maxlen);
                                if (nbuf == NULL) {
                                        el_free(buf);
                                        return -1;
                                }
                                buf = nbuf;
                        }
                        strvis(buf, ptr, VIS_NL);
                        (void) fprintf(el->el_outfile, "%d\t%s\n",
                            hno++, buf);
                }
                el_free(buf);
                return 0;
        }

        if (argc != 3)
                return -1;

        num = (int)wcstol(argv[2], NULL, 0);

        if (wcscmp(argv[1], L"size") == 0)
                return history_w(el->el_history.ref, &ev, H_SETSIZE, num);

        if (wcscmp(argv[1], L"unique") == 0)
                return history_w(el->el_history.ref, &ev, H_SETUNIQUE, num);

        return -1;
}

/* hist_enlargebuf()
 *      Enlarge history buffer to specified value. Called from el_enlargebufs().
 *      Return 0 for failure, 1 for success.
 */
libedit_private int
/*ARGSUSED*/
hist_enlargebuf(EditLine *el, size_t newsz)
{
        wchar_t *newbuf;
        size_t oldsz = el->el_history.sz;

        if (newsz <= oldsz)
                return 1;

        newbuf = el_realloc(el->el_history.buf, newsz * sizeof(*newbuf));
        if (!newbuf)
                return 0;

        (void) memset(&newbuf[oldsz], '\0', (newsz - oldsz) * sizeof(*newbuf));

        el->el_history.last = newbuf +
                                (el->el_history.last - el->el_history.buf);
        el->el_history.buf = newbuf;
        el->el_history.sz  = newsz;

        return 1;
}

libedit_private wchar_t *
hist_convert(EditLine *el, int fn, void *arg)
{
        HistEventW ev;
        if ((*(el)->el_history.fun)((el)->el_history.ref, &ev, fn, arg) == -1)
                return NULL;
        return ct_decode_string((const char *)(const void *)ev.str,
            &el->el_scratch);
}