readline.c

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 * abs(pos); continue backward, if pos<0, forward otherwise
 */
/* ARGSUSED */
int
history_search_pos(const char *str, int direction, int pos)
{
	HistEvent ev;
	int curr_num, off;

	off = (pos > 0) ? pos : -pos;
	pos = (pos > 0) ? 1 : -1;

	if (history(h, &ev, H_CURR) != 0)
		return (-1);
	curr_num = ev.num;

	if (history_set_pos(off) != 0 || history(h, &ev, H_CURR) != 0)
		return (-1);


	for (;;) {
		if (strstr(ev.str, str))
			return (off);
		if (history(h, &ev, (pos < 0) ? H_PREV : H_NEXT) != 0)
			break;
	}

	/* set "current" pointer back to previous state */
	history(h, &ev, (pos < 0) ? H_NEXT_EVENT : H_PREV_EVENT, curr_num);

	return (-1);
}


/********************************/
/* completition functions	*/

/*
 * does tilde expansion of strings of type ``~user/foo''
 * if ``user'' isn't valid user name or ``txt'' doesn't start
 * w/ '~', returns pointer to strdup()ed copy of ``txt''
 *
 * it's callers's responsibility to free() returned string
 */
char *
tilde_expand(char *txt)
{
	struct passwd *pass;
	char *temp;
	size_t len = 0;

	if (txt[0] != '~')
		return (strdup(txt));

	temp = strchr(txt + 1, '/');
	if (temp == NULL)
		temp = strdup(txt + 1);
	else {
		len = temp - txt + 1;	/* text until string after slash */
		temp = malloc(len);
		(void) strncpy(temp, txt + 1, len - 2);
		temp[len - 2] = '\0';
	}
	pass = getpwnam(temp);
	free(temp);		/* value no more needed */
	if (pass == NULL)
		return (strdup(txt));

	/* update pointer txt to point at string immedially following */
	/* first slash */
	txt += len;

	temp = malloc(strlen(pass->pw_dir) + 1 + strlen(txt) + 1);
	(void) sprintf(temp, "%s/%s", pass->pw_dir, txt);

	return (temp);
}


/*
 * return first found file name starting by the ``text'' or NULL if no
 * such file can be found.
 * The first ``state'' matches are ignored.
 *
 * it's caller's responsibility to free returned string
 */
char *
filename_completion_function(const char *text, int state)
{
	DIR *dir = NULL;
	char *filename = NULL, *dirname = NULL;
	size_t filename_len = 0;
	struct dirent *entry;
	char *temp;
	size_t len;

	temp = strrchr(text, '/');
	if (temp) {
		temp++;
		filename = realloc(filename, strlen(temp) + 1);
		(void) strcpy(filename, temp);
		len = temp - text;	/* including last slash */
		dirname = realloc(dirname, len + 1);
		(void) strncpy(dirname, text, len);
		dirname[len] = '\0';
	} else {
		filename = strdup(text);
		dirname = NULL;
	}

	/* support for ``~user'' syntax */
	if (dirname && *dirname == '~') {
		temp = tilde_expand(dirname);
		dirname = realloc(dirname, strlen(temp) + 1);
		(void) strcpy(dirname, temp);	/* safe */
		free(temp);	/* no longer needed */
	}
	/* will be used in cycle */
	filename_len = strlen(filename);

	dir = opendir(dirname ? dirname : ".");
	if (!dir)
		return (NULL);	/* cannot open the directory */

	/* find the match */
	while ((entry = readdir(dir)) != NULL) {
		/* otherwise, get first entry where first */
		/* filename_len characters are equal	  */
		if (
#if defined(__SVR4) || defined(__linux__)
		    strlen(entry->d_name) >= filename_len
#else
		    entry->d_namlen >= filename_len
#endif
		    && strncmp(entry->d_name, filename,
			filename_len) == 0
			&& (state-- == 0))
			break;
	}

	if (entry) {		/* match found */

		struct stat stbuf;
#if defined(__SVR4) || defined(__linux__)
		len = strlen(entry->d_name) +
#else
		len = entry->d_namlen +
#endif
		    ((dirname) ? strlen(dirname) : 0) + 1 + 1;
		temp = malloc(len);
		(void) sprintf(temp, "%s%s",
		    dirname ? dirname : "", entry->d_name);	/* safe */

		/* test, if it's directory */
		if (stat(temp, &stbuf) == 0 && S_ISDIR(stbuf.st_mode))
			strcat(temp, "/");	/* safe */
	} else
		temp = NULL;
	closedir(dir);

	return (temp);
}


/*
 * a completion generator for usernames; returns _first_ username
 * which starts with supplied text
 * text contains a partial username preceded by random character
 * (usually '~'); state is ignored
 * it's callers responsibility to free returned value
 */
char *
username_completion_function(const char *text, int state)
{
	struct passwd *pwd;

	if (text[0] == '\0')
		return (NULL);

	if (*text == '~')
		text++;

	if (state == 0)
		setpwent();

	while ((pwd = getpwent()) && text[0] == pwd->pw_name[0]
	    && strcmp(text, pwd->pw_name) == 0);

	if (pwd == NULL) {
		endpwent();
		return (NULL);
	}
	return (strdup(pwd->pw_name));
}


/*
 * el-compatible wrapper around rl_complete; needed for key binding
 */
/* ARGSUSED */
static unsigned char
_el_rl_complete(EditLine *el, int ch)
{
	return (unsigned char) rl_complete(0, ch);
}


/*
 * returns list of completitions for text given
 */
char **
completion_matches(const char *text, CPFunction *genfunc)
{
	char **match_list = NULL, *retstr, *prevstr;
	size_t match_list_len, max_equal, which, i;
	int matches;

	if (h == NULL || e == NULL)
		rl_initialize();

	matches = 0;
	match_list_len = 1;
	while ((retstr = (*genfunc) (text, matches)) != NULL) {
		if (matches + 1 >= match_list_len) {
			match_list_len <<= 1;
			match_list = realloc(match_list,
			    match_list_len * sizeof(char *));
		}
		match_list[++matches] = retstr;
	}

	if (!match_list)
		return (char **) NULL;	/* nothing found */

	/* find least denominator and insert it to match_list[0] */
	which = 2;
	prevstr = match_list[1];
	max_equal = strlen(prevstr);
	for (; which <= matches; which++) {
		for (i = 0; i < max_equal &&
		    prevstr[i] == match_list[which][i]; i++)
			continue;
		max_equal = i;
	}

	retstr = malloc(max_equal + 1);
	(void) strncpy(retstr, match_list[1], max_equal);
	retstr[max_equal] = '\0';
	match_list[0] = retstr;

	/* add NULL as last pointer to the array */
	if (matches + 1 >= match_list_len)
		match_list = realloc(match_list,
		    (match_list_len + 1) * sizeof(char *));
	match_list[matches + 1] = (char *) NULL;

	return (match_list);
}

/*
 * Sort function for qsort(). Just wrapper around strcasecmp().
 */
static int
_rl_qsort_string_compare(i1, i2)
	const void *i1, *i2;
{
	/* LINTED const castaway */
	const char *s1 = ((const char **)i1)[0];
	/* LINTED const castaway */
	const char *s2 = ((const char **)i2)[0];

	return strcasecmp(s1, s2);
}

/*
 * Display list of strings in columnar format on readline's output stream.
 * 'matches' is list of strings, 'len' is number of strings in 'matches',
 * 'max' is maximum length of string in 'matches'.
 */
void
rl_display_match_list (matches, len, max)
     char **matches;
     int len, max;
{
	int i, idx, limit, count;
	int screenwidth = e->el_term.t_size.h;

	/*
	 * Find out how many entries can be put on one line, count
	 * with two spaces between strings.
	 */
	limit = screenwidth / (max + 2);
	if (limit == 0)
		limit = 1;

	/* how many lines of output */
	count = len / limit;
	if (count * limit < len)
		count++;

	/* Sort the items if they are not already sorted. */
	qsort(&matches[1], (size_t)(len - 1), sizeof(char *),
	    _rl_qsort_string_compare);

	idx = 1;
	for(; count > 0; count--) {
		for(i=0; i < limit && matches[idx]; i++, idx++)
			fprintf(e->el_outfile, "%-*s  ", max, matches[idx]);
		fprintf(e->el_outfile, "\n");
	}
}

/*
 * Complete the word at or before point, called by rl_complete()
 * 'what_to_do' says what to do with the completion.
 * `?' means list the possible completions.
 * TAB means do standard completion.
 * `*' means insert all of the possible completions.
 * `!' means to do standard completion, and list all possible completions if
 * there is more than one.
 *
 * Note: '*' support is not implemented
 */
static int
rl_complete_internal(int what_to_do)
{
	CPFunction *complet_func;
	const LineInfo *li;
	char *temp, **matches;
	const char *ctemp;
	size_t len;

	rl_completion_type = what_to_do;

	if (h == NULL || e == NULL)
		rl_initialize();

	complet_func = rl_completion_entry_function;
	if (!complet_func)
		complet_func = filename_completion_function;

	/* We now look backwards for the start of a filename/variable word */
	li = el_line(e);
	ctemp = (const char *) li->cursor;
	while (ctemp > li->buffer
	    && !strchr(rl_basic_word_break_characters, ctemp[-1])
	    && (!rl_special_prefixes
			|| !strchr(rl_special_prefixes, ctemp[-1]) ) )
		ctemp--;

	len = li->cursor - ctemp;
	temp = alloca(len + 1);
	(void) strncpy(temp, ctemp, len);
	temp[len] = '\0';

	/* these can be used by function called in completion_matches() */
	/* or (*rl_attempted_completion_function)() */
	rl_point = li->cursor - li->buffer;
	rl_end = li->lastchar - li->buffer;

	if (!rl_attempted_completion_function)
		matches = completion_matches(temp, complet_func);
	else {
		int end = li->cursor - li->buffer;
		matches = (*rl_attempted_completion_function) (temp, (int)
		    (end - len), end);
	}

	if (matches) {
		int i, retval = CC_REFRESH;
		int matches_num, maxlen, match_len, match_display=1;

		/*
		 * Only replace the completed string with common part of
		 * possible matches if there is possible completion.
		 */
		if (matches[0][0] != '\0') {
			el_deletestr(e, (int) len);
			el_insertstr(e, matches[0]);
		}

		if (what_to_do == '?')
			goto display_matches;

		if (matches[2] == NULL && strcmp(matches[0], matches[1]) == 0) {
			/*
			 * We found exact match. Add a space after
			 * it, unless we do filename completition and the
			 * object is a directory.
			 */
			size_t alen = strlen(matches[0]);
			if ((complet_func != filename_completion_function
			      || (alen > 0 && (matches[0])[alen - 1] != '/'))
			    && rl_completion_append_character) {
				char buf[2];
				buf[0] = rl_completion_append_character;
				buf[1] = '\0';
				el_insertstr(e, buf);
			}
		} else if (what_to_do == '!') {
    display_matches:
			/*
			 * More than one match and requested to list possible
			 * matches.
			 */

			for(i=1, maxlen=0; matches[i]; i++) {
				match_len = strlen(matches[i]);
				if (match_len > maxlen)
					maxlen = match_len;
			}
			matches_num = i - 1;
				
			/* newline to get on next line from command line */
			fprintf(e->el_outfile, "\n");

			/*
			 * If there are too many items, ask user for display
			 * confirmation.
			 */
			if (matches_num > rl_completion_query_items) {
				fprintf(e->el_outfile,
				"Display all %d possibilities? (y or n) ",
					matches_num);
				fflush(e->el_outfile);
				if (getc(stdin) != 'y')
					match_display = 0;
				fprintf(e->el_outfile, "\n");
			}

			if (match_display)
				rl_display_match_list(matches, matches_num,
					maxlen);
			retval = CC_REDISPLAY;
		} else if (matches[0][0]) {
			/*
			 * There was some common match, but the name was
			 * not complete enough. Next tab will print possible
			 * completions.
			 */
			el_beep(e);
		} else {
			/* lcd is not a valid object - further specification */
			/* is needed */
			el_beep(e);
			retval = CC_NORM;
		}

		/* free elements of array and the array itself */
		for (i = 0; matches[i]; i++)
			free(matches[i]);
		free(matches), matches = NULL;

		return (retval);
	}
	return (CC_NORM);
}


/*
 * complete word at current point
 */
int
rl_complete(int ignore, int invoking_key)
{
	if (h == NULL || e == NULL)
		rl_initialize();

	if (rl_inhibit_completion) {
		rl_insert(ignore, invoking_key);
		return (CC_REFRESH);
	} else if (e->el_state.lastcmd == el_rl_complete_cmdnum)
		return rl_complete_internal('?');
	else if (_rl_complete_show_all)
		return rl_complete_internal('!');
	else
		return (rl_complete_internal(TAB));
}


/*
 * misc other functions
 */

/*
 * bind key c to readline-type function func
 */
int
rl_bind_key(int c, int func(int, int))
{
	int retval = -1;

	if (h == NULL || e == NULL)
		rl_initialize();

	if (func == rl_insert) {
		/* XXX notice there is no range checking of ``c'' */
		e->el_map.key[c] = ED_INSERT;
		retval = 0;
	}
	return (retval);
}


/*
 * read one key from input - handles chars pushed back
 * to input stream also
 */
int
rl_read_key(void)
{
	char fooarr[2 * sizeof(int)];

	if (e == NULL || h == NULL)
		rl_initialize();

	return (el_getc(e, fooarr));
}


/*
 * reset the terminal
 */
/* ARGSUSED */
void
rl_reset_terminal(const char *p)
{

	if (h == NULL || e == NULL)
		rl_initialize();
	el_reset(e);
}


/*
 * insert character ``c'' back into input stream, ``count'' times
 */
int
rl_insert(int count, int c)
{
	char arr[2];

	if (h == NULL || e == NULL)
		rl_initialize();

	/* XXX - int -> char conversion can lose on multichars */
	arr[0] = c;
	arr[1] = '\0';

	for (; count > 0; count--)
		el_push(e, arr);

	return (0);
}