ex.c

操作系统源代码

	{
	}

	/* ignore command lines that start with a double-quote */
	if (*cmdbuf == '"')
	{
		return;
	}
	scan = cmdbuf;

	/* parse the line specifier */
	if (nlines < 1)
	{
		/* no file, so don't allow addresses */
	}
	else if (*scan == '%')
	{
		/* '%' means all lines */
		frommark = MARK_FIRST;
		tomark = MARK_LAST;
		scan++;
	}
	else if (*scan == '0')
	{
		frommark = tomark = MARK_UNSET;
		scan++;
	}
	else
	{
		frommark = cursor;
		scan = linespec(scan, &frommark);
		tomark = frommark;
		if (frommark && *scan == ',')
		{
			scan++;
			scan = linespec(scan, &tomark);
		}
		if (!tomark)
		{
			/* faulty line spec -- fault already described */
			return;
		}
		if (frommark > tomark)
		{
			msg("first address exceeds the second");
			return;
		}
	}
	isdfl = (scan == cmdbuf);

	/* skip whitespace */
	while (isspace(*scan))
	{
		scan++;
	}

	/* if no command, then just move the cursor to the mark */
	if (!*scan)
	{
		if (tomark != MARK_UNSET)
			cursor = tomark;
		return;
	}

	/* figure out how long the command name is */
	if (!isalpha(*scan))
	{
		cmdlen = 1;
	}
	else
	{
		for (cmdlen = 1;
		     isalpha(scan[cmdlen]);
		     cmdlen++)
		{
		}
	}

	/* lookup the command code */
	for (cmdidx = 0;
	     cmdnames[cmdidx].name && strncmp(scan, cmdnames[cmdidx].name, cmdlen);
	     cmdidx++)
	{
	}
	argt = cmdnames[cmdidx].argt;
	cmd = cmdnames[cmdidx].code;
	if (cmd == CMD_NULL)
	{
		msg("Unknown command \"%.*s\"", cmdlen, scan);
		return;
	}

	/* !!! if the command doesn't have NOBAR set, then replace | with \0 */

	/* if the command ended with a bang, set the forceit flag */
	scan += cmdlen;
	if ((argt & BANG) && *scan == '!')
	{
		scan++;
		forceit = 1;
	}
	else
	{
		forceit = 0;
	}

	/* skip any more whitespace, to leave scan pointing to arguments */
	while (isspace(*scan))
	{
		scan++;
	}

	/* a couple of special cases for filenames */
	if (argt & XFILE)
	{
		/* if names were given, process them */
		if (*scan)
		{
			for (build = tmpblk.c, iswild = didsub = FALSE; *scan; scan++)
			{
				switch (*scan)
				{
				  case '\\':
					if (scan[1] == '\\' || scan[1] == '%' || scan[1] == '#')
					{
						*build++ = *++scan;
					}
					else
					{
						*build++ = '\\';
					}
					break;

				  case '%':
					if (!*origname)
					{
						msg("No filename to substitute for %%");
						return;
					}
					strcpy(build, origname);
					while (*build)
					{
						build++;
					}
					didsub = TRUE;
					break;

				  case '#':
					if (!*prevorig)
					{
						msg("No filename to substitute for #");
						return;
					}
					strcpy(build, prevorig);
					while (*build)
					{
						build++;
					}
					didsub = TRUE;
					break;

				  case '*':
				  case '?':
#if !(MSDOS || TOS)
				  case '[':
				  case '`':
				  case '{': /* } */
				  case '$':
				  case '~':
#endif
					*build++ = *scan;
					iswild = TRUE;
					break;

				  default:
					*build++ = *scan;
				}
			}
			*build = '\0';

			if (cmd == CMD_BANG
			 || cmd == CMD_READ && tmpblk.c[0] == '!'
			 || cmd == CMD_WRITE && tmpblk.c[0] == '!')
			{
				if (didsub)
				{
					if (mode != MODE_EX)
					{
						addch('\n');
					}
					addstr(tmpblk.c);
					addch('\n');
					exrefresh();
				}
			}
			else
			{
				if (iswild && tmpblk.c[0] != '>')
				{
					scan = wildcard(tmpblk.c);
				}
			}
		}
		else /* no names given, maybe assume origname */
		{
			if (!(argt & NODFL))
			{
				strcpy(tmpblk.c, origname);
			}
			else
			{
				*tmpblk.c = '\0';
			}
		}

		scan = tmpblk.c;
	}

	/* bad arguments? */
	if (!(argt & EXRCOK) && nlines < 1L)
	{
		msg("Can't use the \"%s\" command in a %s file", cmdnames[cmdidx].name, EXRC);
		return;
	}
	if (!(argt & (ZERO | EXRCOK)) && frommark == MARK_UNSET)
	{
		msg("Can't use address 0 with \"%s\" command.", cmdnames[cmdidx].name);
		return;
	}
	if (!(argt & FROM) && frommark != cursor && nlines >= 1L)
	{
		msg("Can't use address with \"%s\" command.", cmdnames[cmdidx].name);
		return;
	}
	if (!(argt & TO) && tomark != frommark && nlines >= 1L)
	{
		msg("Can't use a range with \"%s\" command.", cmdnames[cmdidx].name);
		return;
	}
	if (!(argt & EXTRA) && *scan)
	{
		msg("Extra characters after \"%s\" command.", cmdnames[cmdidx].name);
		return;
	}
	if ((argt & NOSPC) && !(cmd == CMD_READ && (forceit || *scan == '!')))
	{
		build = scan;
#ifndef CRUNCH
		if ((argt & PLUS) && *build == '+')
		{
			while (*build && !isspace(*build))
			{
				build++;
			}
			while (*build && isspace(*build))
			{
				build++;
			}
		}
#endif /* not CRUNCH */
		for (; *build; build++)
		{
			if (isspace(*build))
			{
				msg("Too many %s to \"%s\" command.",
					(argt & XFILE) ? "filenames" : "arguments",
					cmdnames[cmdidx].name);
				return;
			}
		}
	}

	/* some commands have special default ranges */
	if (isdfl && (argt & DFLALL))
	{
		frommark = MARK_FIRST;
		tomark = MARK_LAST;
	}
	else if (isdfl && (argt & DFLNONE))
	{
		frommark = tomark = 0L;
	}

	/* write a newline if called from visual mode */
	if ((argt & NL) && mode != MODE_EX && !exwrote)
	{
		addch('\n');
		exrefresh();
	}

	/* act on the command */
	(*cmdnames[cmdidx].fn)(frommark, tomark, cmd, forceit, scan);
}


/* This function executes EX commands from a file.  It returns 1 normally, or
 * 0 if the file could not be opened for reading.
 */
int doexrc(filename)
	char	*filename;	/* name of a ".exrc" file */
{
	int	fd;		/* file descriptor */
	int	len;		/* length of the ".exrc" file */

	/* !!! kludge: we use U_text as the buffer.  This has the side-effect
	 * of interfering with the shift-U visual command.  Disable shift-U.
	 */
	U_line = 0L;

	/* open the file, read it, and close */
	fd = open(filename, O_RDONLY);
	if (fd < 0)
	{
		return 0;
	}
	len = tread(fd, U_text, BLKSIZE);
	close(fd);

	/* execute the string */
	exstring(U_text, len, ctrl('V'));

	return 1;
}

/* This function executes EX commands from a string.  The commands may be
 * separated by newlines or by | characters.  It also handles quoting.
 * Each individual command is limited to 132 bytes, but the total string
 * may be longer.
 */
void exstring(buf, len, qchar)
	char	*buf;	/* the commands to execute */
	int	len;	/* the length of the string */
	int	qchar;	/* the quote character -- ^V for file, or \ for kbd */
{
	char	single[133];	/* a single command */
	char	*src, *dest;
	int	i;

	/* find & do each command */
	for (src = buf; src < &buf[len]; src++)
	{
		/* Copy a single command into single[].  Convert any quoted |
		 * into a normal |, and stop at a newline or unquoted |.
		 */
		for (dest = single, i = 0;
		     i < 132 && src < &buf[len] && *src != '\n' && *src != '|';
		     src++, i++)
		{
			if (src[0] == qchar && src[1] == '|')
			{
				src++;
			}
			*dest++ = *src;
		}
		*dest = '\0';

		/* do it */
		doexcmd(single);
	}
}