/*-
 * Copyright (c) 1991, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char sccsid[] = "@(#)util.c	8.74 (Berkeley) 8/17/94";
#endif /* not lint */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

#include "compat.h"
#include <curses.h>
#include <db.h>
#include <regex.h>

#include "vi.h"

/*
 * binc --
 *	Increase the size of a buffer.
 */
void *
binc(sp, bp, bsizep, min)
	SCR *sp;			/* sp MAY BE NULL!!! */
	void *bp;
	size_t *bsizep, min;
{
	size_t csize;

	/* If already larger than the minimum, just return. */
	if (min && *bsizep >= min)
		return (bp);

	csize = *bsizep + MAX(min, 256);
	REALLOC(sp, bp, void *, csize);

	if (bp == NULL) {
		/*
		 * Theoretically, realloc is supposed to leave any already
		 * held memory alone if it can't get more.  Don't trust it.
		 */
		*bsizep = 0;
		return (NULL);
	}
	/*
	 * Memory is guaranteed to be zero-filled, various parts of
	 * nvi depend on this.
	 */
	memset((char *)bp + *bsizep, 0, csize - *bsizep);
	*bsizep = csize;
	return (bp);
}

/*
 * nonblank --
 *	Set the column number of the first non-blank character
 *	including or after the starting column.  On error, set
 *	the column to 0, it's safest.
 */
int
nonblank(sp, ep, lno, cnop)
	SCR *sp;
	EXF *ep;
	recno_t lno;
	size_t *cnop;
{
	char *p;
	size_t cnt, len, off;

	/* Default. */
	off = *cnop;
	*cnop = 0;

	/* Get the line. */
	if ((p = file_gline(sp, ep, lno, &len)) == NULL) {
		if (file_lline(sp, ep, &lno))
			return (1);
		if (lno == 0)
			return (0);
		GETLINE_ERR(sp, lno);
		return (1);
	}

	/* Set the offset. */
	if (len == 0 || off >= len)
		return (0);

	for (cnt = off, p = &p[off],
	    len -= off; len && isblank(*p); ++cnt, ++p, --len);

	/* Set the return. */
	*cnop = len ? cnt : cnt - 1;
	return (0);
}

/*
 * tail --
 *	Return tail of a path.
 */
char *
tail(path)
	char *path;
{
	char *p;

	if ((p = strrchr(path, '/')) == NULL)
		return (path);
	return (p + 1);
}

/*
 * set_alt_name --
 *	Set the alternate file name.
 *
 * Swap the alternate file name.  It's a routine because I wanted some place
 * to hang this comment.  The alternate file name (normally referenced using
 * the special character '#' during file expansion) is set by many
 * operations.  In the historic vi, the commands "ex", and "edit" obviously
 * set the alternate file name because they switched the underlying file.
 * Less obviously, the "read", "file", "write" and "wq" commands set it as
 * well.  In this implementation, some new commands have been added to the
 * list.  Where it gets interesting is that the alternate file name is set
 * multiple times by some commands.  If an edit attempt fails (for whatever
 * reason, like the current file is modified but as yet unwritten), it is
 * set to the file name that the user was unable to edit.  If the edit
 * succeeds, it is set to the last file name that was edited.  Good fun.
 *
 * If the user edits a temporary file, there are time when there isn't an
 * alternative file name.  A name argument of NULL turns it off.
 */
void
set_alt_name(sp, name)
	SCR *sp;
	char *name;
{
	if (sp->alt_name != NULL)
		free(sp->alt_name);
	if (name == NULL)
		sp->alt_name = NULL;
	else if ((sp->alt_name = strdup(name)) == NULL)
		msgq(sp, M_SYSERR, NULL);
}

/*
 * v_strdup --
 *	Strdup for wide character strings with an associated length.
 */
CHAR_T *
v_strdup(sp, str, len)
	SCR *sp;
	CHAR_T *str;
	size_t len;
{
	CHAR_T *copy;

	MALLOC(sp, copy, CHAR_T *, len + 1);
	if (copy == NULL)
		return (NULL);
	memmove(copy, str, len * sizeof(CHAR_T));
	copy[len] = '\0';
	return (copy);
}

/*
 * vi_putchar --
 *	Functional version of putchar, for tputs.
 */
void
vi_putchar(ch)
	int ch;
{
	(void)putchar(ch);
}