path: root/src/help.c

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * help.c: functions for Vim help
 */

#include "vim.h"

/*
 * ":help": open a read-only window on a help file
 */
    void
ex_help(exarg_T *eap)
{
    char_u	*arg;
    char_u	*tag;
    FILE	*helpfd;	// file descriptor of help file
    int		n;
    int		i;
    win_T	*wp;
    int		num_matches;
    char_u	**matches;
    char_u	*p;
    int		empty_fnum = 0;
    int		alt_fnum = 0;
    buf_T	*buf;
#ifdef FEAT_MULTI_LANG
    int		len;
    char_u	*lang;
#endif
#ifdef FEAT_FOLDING
    int		old_KeyTyped = KeyTyped;
#endif

    if (ERROR_IF_ANY_POPUP_WINDOW)
	return;

    if (eap != NULL)
    {
	// A ":help" command ends at the first LF, or at a '|' that is
	// followed by some text.  Set nextcmd to the following command.
	for (arg = eap->arg; *arg; ++arg)
	{
	    if (*arg == '\n' || *arg == '\r'
		    || (*arg == '|' && arg[1] != NUL && arg[1] != '|'))
	    {
		*arg++ = NUL;
		eap->nextcmd = arg;
		break;
	    }
	}
	arg = eap->arg;

	if (eap->forceit && *arg == NUL && !curbuf->b_help)
	{
	    emsg(_("E478: Don't panic!"));
	    return;
	}

	if (eap->skip)	    // not executing commands
	    return;
    }
    else
	arg = (char_u *)"";

    // remove trailing blanks
    p = arg + STRLEN(arg) - 1;
    while (p > arg && VIM_ISWHITE(*p) && p[-1] != '\\')
	*p-- = NUL;

#ifdef FEAT_MULTI_LANG
    // Check for a specified language
    lang = check_help_lang(arg);
#endif

    // When no argument given go to the index.
    if (*arg ==</