Пример #1
0
/*
 * Analogous to back_line(), but deals with "raw lines".
 * {{ This is supposed to be more efficient than back_line(). }}
 */
off_t
back_raw_line(off_t curr_pos, char **linep, int *line_lenp)
{
	int n;
	int c;
	off_t new_pos;

	if (curr_pos == -1 || curr_pos <= ch_zero() || ch_seek(curr_pos - 1))
		return (-1);

	n = size_linebuf;
	linebuf[--n] = '\0';
	for (;;) {
		c = ch_back_get();
		if (c == '\n' || ABORT_SIGS()) {
			/*
			 * This is the newline ending the previous line.
			 * We have hit the beginning of the line.
			 */
			new_pos = ch_tell() + 1;
			break;
		}
		if (c == EOI) {
			/*
			 * We have hit the beginning of the file.
			 * This must be the first line in the file.
			 * This must, of course, be the beginning of the line.
			 */
			new_pos = ch_zero();
			break;
		}
		if (n <= 0) {
			int old_size_linebuf = size_linebuf;
			char *fm;
			char *to;
			if (expand_linebuf()) {
				/*
				 * Overflowed the input buffer.
				 * Pretend the line ended here.
				 */
				new_pos = ch_tell() + 1;
				break;
			}
			/*
			 * Shift the data to the end of the new linebuf.
			 */
			for (fm = linebuf + old_size_linebuf - 1,
			    to = linebuf + size_linebuf - 1;
			    fm >= linebuf;  fm--, to--)
				*to = *fm;
			n = size_linebuf - old_size_linebuf;
		}
		linebuf[--n] = c;
	}
	if (linep != NULL)
		*linep = &linebuf[n];
	if (line_lenp != NULL)
		*line_lenp = size_linebuf - 1 - n;
	return (new_pos);
}
Пример #2
0
/*
 * Get the next line.
 * A "current" position is passed and a "new" position is returned.
 * The current position is the position of the first character of
 * a line.  The new position is the position of the first character
 * of the NEXT line.  The line obtained is the line starting at curr_pos.
 */
off_t
forw_line(off_t curr_pos)
{
	off_t new_pos;
	int c;

	if (curr_pos == NULL_POSITION || ch_seek(curr_pos))
		return (NULL_POSITION);

	c = ch_forw_get();
	if (c == EOI)
		return (NULL_POSITION);

	prewind();
	for (;;) {
		if (sigs)
			return (NULL_POSITION);
		if (c == '\n' || c == EOI) {
			/*
			 * End of the line.
			 */
			new_pos = ch_tell();
			break;
		}

		/*
		 * Append the char to the line and get the next char.
		 */
		if (pappend(c)) {
			/*
			 * The char won't fit in the line; the line
			 * is too long to print in the screen width.
			 * End the line here.
			 */
			new_pos = ch_tell() - 1;
			break;
		}
		c = ch_forw_get();
	}
	(void) pappend('\0');

	if (squeeze && *line == '\0') {
		/*
		 * This line is blank.
		 * Skip down to the last contiguous blank line
		 * and pretend it is the one which we are returning.
		 */
		while ((c = ch_forw_get()) == '\n')
			if (sigs)
				return (NULL_POSITION);
		if (c != EOI)
			(void) ch_back_get();
		new_pos = ch_tell();
	}

	return (new_pos);
}
Пример #3
0
/*
 * Analogous to back_line(), but deals with "raw lines".
 * {{ This is supposed to be more efficient than back_line(). }}
 */
off_t
back_raw_line(off_t curr_pos)
{
	char *p;
	int c;
	off_t new_pos;

	if (curr_pos == NULL_POSITION || curr_pos <= (off_t)0 ||
	    ch_seek(curr_pos-1))
		return (NULL_POSITION);

	p = &linebuf[sizeof(linebuf)];
	*--p = '\0';

	for (;;) {
		c = ch_back_get();
		if (c == '\n') {
			/*
			 * This is the newline ending the previous line.
			 * We have hit the beginning of the line.
			 */
			new_pos = ch_tell() + 1;
			break;
		}
		if (c == EOI) {
			/*
			 * We have hit the beginning of the file.
			 * This must be the first line in the file.
			 * This must, of course, be the beginning of the line.
			 */
			new_pos = (off_t)0;
			break;
		}
		if (p <= linebuf) {
			/*
			 * Overflowed the input buffer.
			 * Pretend the line ended here.
			 */
			new_pos = ch_tell() + 1;
			break;
		}
		*--p = c;
	}
	line = p;
	return (new_pos);
}
Пример #4
0
/*
 * Get the mark structure identified by a character.
 * The mark struct may come either from the mark table
 * or may be constructed on the fly for certain characters like ^, $.
 */
static struct mark *
getmark(int c)
{
	register struct mark *m;
	static struct mark sm;

	switch (c) {
	case '^':
		/*
		 * Beginning of the current file.
		 */
		m = &sm;
		m->m_scrpos.pos = ch_zero();
		m->m_scrpos.ln = 0;
		m->m_ifile = curr_ifile;
		break;
	case '$':
		/*
		 * End of the current file.
		 */
		if (ch_end_seek()) {
			error("Cannot seek to end of file", NULL_PARG);
			return (NULL);
		}
		m = &sm;
		m->m_scrpos.pos = ch_tell();
		m->m_scrpos.ln = sc_height-1;
		m->m_ifile = curr_ifile;
		break;
	case '.':
		/*
		 * Current position in the current file.
		 */
		m = &sm;
		get_scrpos(&m->m_scrpos);
		m->m_ifile = curr_ifile;
		break;
	case '\'':
		/*
		 * The "last mark".
		 */
		m = &marks[LASTMARK];
		break;
	default:
		/*
		 * Must be a user-defined mark.
		 */
		m = getumark(c);
		if (m == NULL)
			break;
		if (m->m_scrpos.pos == -1) {
			error("Mark not set", NULL_PARG);
			return (NULL);
		}
		break;
	}
	return (m);
}
Пример #5
0
/*
 * Analogous to forw_line(), but deals with "raw lines":
 * lines which are not split for screen width.
 * {{ This is supposed to be more efficient than forw_line(). }}
 */
off_t
forw_raw_line(off_t curr_pos, char **linep, int *line_lenp)
{
	int n;
	int c;
	off_t new_pos;

	if (curr_pos == -1 || ch_seek(curr_pos) ||
	    (c = ch_forw_get()) == EOI)
		return (-1);

	n = 0;
	for (;;) {
		if (c == '\n' || c == EOI || ABORT_SIGS()) {
			new_pos = ch_tell();
			break;
		}
		if (n >= size_linebuf-1) {
			if (expand_linebuf()) {
				/*
				 * Overflowed the input buffer.
				 * Pretend the line ended here.
				 */
				new_pos = ch_tell() - 1;
				break;
			}
		}
		linebuf[n++] = (char)c;
		c = ch_forw_get();
	}
	linebuf[n] = '\0';
	if (linep != NULL)
		*linep = linebuf;
	if (line_lenp != NULL)
		*line_lenp = n;
	return (new_pos);
}
Пример #6
0
/*
 * Analogous to forw_line(), but deals with "raw lines":
 * lines which are not split for screen width.
 * {{ This is supposed to be more efficient than forw_line(). }}
 */
off_t
forw_raw_line(off_t curr_pos)
{
	char *p;
	int c;
	off_t new_pos;

	if (curr_pos == NULL_POSITION || ch_seek(curr_pos) ||
		(c = ch_forw_get()) == EOI)
		return (NULL_POSITION);

	p = linebuf;

	for (;;) {
		if (c == '\n' || c == EOI) {
			new_pos = ch_tell();
			break;
		}

		if (p >= &linebuf[sizeof(linebuf)-1]) {
			/*
			 * Overflowed the input buffer.
			 * Pretend the line ended here.
			 * {{ The line buffer is supposed to be big
			 *    enough that this never happens. }}
			 */
			new_pos = ch_tell() - 1;
			break;
		}
		*p++ = c;
		c = ch_forw_get();
	}
	*p = '\0';
	line = linebuf;
	return (new_pos);
}
Пример #7
0
/*
 * Get the previous line.
 * A "current" position is passed and a "new" position is returned.
 * The current position is the position of the first character of
 * a line.  The new position is the position of the first character
 * of the PREVIOUS line.  The line obtained is the one starting at new_pos.
 */
off_t
back_line(off_t curr_pos)
{
	off_t new_pos, begin_new_pos;
	int c;

	if (curr_pos == NULL_POSITION || curr_pos <= (off_t)0 ||
		ch_seek(curr_pos-1))
		return (NULL_POSITION);

	if (squeeze) {
		/*
		 * Find out if the "current" line was blank.
		 */
		(void) ch_forw_get();	/* Skip the newline */
		c = ch_forw_get();	/* First char of "current" line */
		(void) ch_back_get();	/* Restore our position */
		(void) ch_back_get();

		if (c == '\n') {
			/*
			 * The "current" line was blank.
			 * Skip over any preceeding blank lines,
			 * since we skipped them in forw_line().
			 */
			while ((c = ch_back_get()) == '\n')
				if (sigs)
					return (NULL_POSITION);
			if (c == EOI)
				return (NULL_POSITION);
			(void) ch_forw_get();
		}
	}

	/*
	 * Scan backwards until we hit the beginning of the line.
	 */
	for (;;) {
		if (sigs)
			return (NULL_POSITION);
		c = ch_back_get();
		if (c == '\n') {
			/*
			 * This is the newline ending the previous line.
			 * We have hit the beginning of the line.
			 */
			new_pos = ch_tell() + 1;
			break;
		}

		if (c == EOI) {
			/*
			 * We have hit the beginning of the file.
			 * This must be the first line in the file.
			 * This must, of course, be the beginning of the line.
			 */
			new_pos = ch_tell();
			break;
		}
	}

	/*
	 * Now scan forwards from the beginning of this line.
	 * We keep discarding "printable lines" (based on screen width)
	 * until we reach the curr_pos.
	 *
	 * {{ This algorithm is pretty inefficient if the lines
	 *    are much longer than the screen width, 
	 *    but I don't know of any better way. }}
	 */
	if (ch_seek(new_pos))
		return (NULL_POSITION);
    loop:
	begin_new_pos = new_pos;
	prewind();

	do {
		c = ch_forw_get();
		if (c == EOI || sigs)
			return (NULL_POSITION);
		new_pos++;
		if (c == '\n')
			break;
		if (pappend(c)) {
			/*
			 * Got a full printable line, but we haven't
			 * reached our curr_pos yet.  Discard the line
			 * and start a new one.
			 */
			(void) pappend('\0');
			(void) ch_back_get();
			new_pos--;
			goto loop;
		}
	} while (new_pos < curr_pos);

	(void) pappend('\0');

	return (begin_new_pos);
}