main.c

 */
int readline (const char *const prompt)
{
	/*
	 * If console_buffer isn't 0-length the user will be prompted to modify
	 * it instead of entering it from scratch as desired.
	 */
	console_buffer[0] = '\0';

	return readline_into_buffer(prompt, console_buffer, 0);
}


int readline_into_buffer(const char *const prompt, char *buffer, int timeout)
{
	char *p = buffer;
#ifdef CONFIG_CMDLINE_EDITING
	unsigned int len = CONFIG_SYS_CBSIZE;
	int rc;
	static int initted = 0;

	/*
	 * History uses a global array which is not
	 * writable until after relocation to RAM.
	 * Revert to non-history version if still
	 * running from flash.
	 */
	if (gd->flags & GD_FLG_RELOC) {
		if (!initted) {
			hist_init();
			initted = 1;
		}

		if (prompt)
			puts (prompt);

		rc = cread_line(prompt, p, &len, timeout);
		return rc < 0 ? rc : len;

	} else {
#endif	/* CONFIG_CMDLINE_EDITING */
	char * p_buf = p;
	int	n = 0;				/* buffer index		*/
	int	plen = 0;			/* prompt length	*/
	int	col;				/* output column cnt	*/
	char	c;

	/* print prompt */
	if (prompt) {
		plen = strlen (prompt);
		puts (prompt);
	}
	col = plen;

	for (;;) {
#ifdef CONFIG_BOOT_RETRY_TIME
		while (!tstc()) {	/* while no incoming data */
			if (retry_time >= 0 && get_ticks() > endtime)
				return (-2);	/* timed out */
			WATCHDOG_RESET();
		}
#endif
		WATCHDOG_RESET();		/* Trigger watchdog, if needed */

#ifdef CONFIG_SHOW_ACTIVITY
		while (!tstc()) {
			show_activity(0);
			WATCHDOG_RESET();
		}
#endif
		c = getc();

		/*
		 * Special character handling
		 */
		switch (c) {
		case '\r':				/* Enter		*/
		case '\n':
			*p = '\0';
			puts ("\r\n");
			return (p - p_buf);

		case '\0':				/* nul			*/
			continue;

		case 0x03:				/* ^C - break		*/
			p_buf[0] = '\0';	/* discard input */
			return (-1);

		case 0x15:				/* ^U - erase line	*/
			while (col > plen) {
				puts (erase_seq);
				--col;
			}
			p = p_buf;
			n = 0;
			continue;

		case 0x17:				/* ^W - erase word	*/
			p=delete_char(p_buf, p, &col, &n, plen);
			while ((n > 0) && (*p != ' ')) {
				p=delete_char(p_buf, p, &col, &n, plen);
			}
			continue;

		case 0x08:				/* ^H  - backspace	*/
		case 0x7F:				/* DEL - backspace	*/
			p=delete_char(p_buf, p, &col, &n, plen);
			continue;

		default:
			/*
			 * Must be a normal character then
			 */
			if (n < CONFIG_SYS_CBSIZE-2) {
				if (c == '\t') {	/* expand TABs		*/
#ifdef CONFIG_AUTO_COMPLETE
					/* if auto completion triggered just continue */
					*p = '\0';
					if (cmd_auto_complete(prompt, console_buffer, &n, &col)) {
						p = p_buf + n;	/* reset */
						continue;
					}
#endif
					puts (tab_seq+(col&07));
					col += 8 - (col&07);
				} else {
					++col;		/* echo input		*/
					putc (c);
				}
				*p++ = c;
				++n;
			} else {			/* Buffer full		*/
				putc ('\a');
			}
		}
	}
#ifdef CONFIG_CMDLINE_EDITING
	}
#endif
}

/****************************************************************************/

static char * delete_char (char *buffer, char *p, int *colp, int *np, int plen)
{
	char *s;

	if (*np == 0) {
		return (p);
	}

	if (*(--p) == '\t') {			/* will retype the whole line	*/
		while (*colp > plen) {
			puts (erase_seq);
			(*colp)--;
		}
		for (s=buffer; s<p; ++s) {
			if (*s == '\t') {
				puts (tab_seq+((*colp) & 07));
				*colp += 8 - ((*colp) & 07);
			} else {
				++(*colp);
				putc (*s);
			}
		}
	} else {
		puts (erase_seq);
		(*colp)--;
	}
	(*np)--;
	return (p);
}

/****************************************************************************/

int parse_line (char *line, char *argv[])
{
	int nargs = 0;

#ifdef DEBUG_PARSER
	printf ("parse_line: \"%s\"\n", line);
#endif
	while (nargs < CONFIG_SYS_MAXARGS) {

		/* skip any white space */
		while (isblank(*line))
			++line;

		if (*line == '\0') {	/* end of line, no more args	*/
			argv[nargs] = NULL;
#ifdef DEBUG_PARSER
		printf ("parse_line: nargs=%d\n", nargs);
#endif
			return (nargs);
		}

		argv[nargs++] = line;	/* begin of argument string	*/

		/* find end of string */
		while (*line && !isblank(*line))
			++line;

		if (*line == '\0') {	/* end of line, no more args	*/
			argv[nargs] = NULL;
#ifdef DEBUG_PARSER
		printf ("parse_line: nargs=%d\n", nargs);
#endif
			return (nargs);
		}

		*line++ = '\0';		/* terminate current arg	 */
	}

	printf ("** Too many args (max. %d) **\n", CONFIG_SYS_MAXARGS);

#ifdef DEBUG_PARSER
	printf ("parse_line: nargs=%d\n", nargs);
#endif
	return (nargs);
}

/****************************************************************************/

#ifndef CONFIG_SYS_HUSH_PARSER
static void process_macros (const char *input, char *output)
{
	char c, prev;
	const char *varname_start = NULL;
	int inputcnt = strlen (input);
	int outputcnt = CONFIG_SYS_CBSIZE;
	int state = 0;		/* 0 = waiting for '$'  */

	/* 1 = waiting for '(' or '{' */
	/* 2 = waiting for ')' or '}' */
	/* 3 = waiting for '''  */
#ifdef DEBUG_PARSER
	char *output_start = output;

	printf ("[PROCESS_MACROS] INPUT len %d: \"%s\"\n", strlen (input),
		input);
#endif

	prev = '\0';		/* previous character   */

	while (inputcnt && outputcnt) {
		c = *input++;
		inputcnt--;

		if (state != 3) {
			/* remove one level of escape characters */
			if ((c == '\\') && (prev != '\\')) {
				if (inputcnt-- == 0)
					break;
				prev = c;
				c = *input++;
			}
		}

		switch (state) {
		case 0:	/* Waiting for (unescaped) $    */
			if ((c == '\'') && (prev != '\\')) {
				state = 3;
				break;
			}
			if ((c == '$') && (prev != '\\')) {
				state++;
			} else {
				*(output++) = c;
				outputcnt--;
			}
			break;
		case 1:	/* Waiting for (        */
			if (c == '(' || c == '{') {
				state++;
				varname_start = input;
			} else {
				state = 0;
				*(output++) = '$';
				outputcnt--;

				if (outputcnt) {
					*(output++) = c;
					outputcnt--;
				}
			}
			break;
		case 2:	/* Waiting for )        */
			if (c == ')' || c == '}') {
				int i;
				char envname[CONFIG_SYS_CBSIZE], *envval;
				int envcnt = input - varname_start - 1;	/* Varname # of chars */

				/* Get the varname */
				for (i = 0; i < envcnt; i++) {
					envname[i] = varname_start[i];
				}
				envname[i] = 0;

				/* Get its value */
				envval = getenv (envname);

				/* Copy into the line if it exists */
				if (envval != NULL)
					while ((*envval) && outputcnt) {
						*(output++) = *(envval++);
						outputcnt--;
					}
				/* Look for another '$' */
				state = 0;
			}
			break;
		case 3:	/* Waiting for '        */
			if ((c == '\'') && (prev != '\\')) {
				state = 0;
			} else {
				*(output++) = c;
				outputcnt--;
			}
			break;
		}
		prev = c;
	}

	if (outputcnt)
		*output = 0;
	else
		*(output - 1) = 0;

#ifdef DEBUG_PARSER
	printf ("[PROCESS_MACROS] OUTPUT len %d: \"%s\"\n",
		strlen (output_start), output_start);
#endif
}

/****************************************************************************
 * returns:
 *	1  - command executed, repeatable
 *	0  - command executed but not repeatable, interrupted commands are
 *	     always considered not repeatable
 *	-1 - not executed (unrecognized, bootd recursion or too many args)
 *           (If cmd is NULL or "" or longer than CONFIG_SYS_CBSIZE-1 it is
 *           considered unrecognized)
 *
 * WARNING:
 *
 * We must create a temporary copy of the command since the command we get
 * may be the result from getenv(), which returns a pointer directly to
 * the environment data, which may change magicly when the command we run
 * creates or modifies environment variables (like "bootp" does).
 */
static int builtin_run_command(const char *cmd, int flag)
{
	char cmdbuf[CONFIG_SYS_CBSIZE];	/* working copy of cmd		*/
	char *token;			/* start of token in cmdbuf	*/
	char *sep;			/* end of token (separator) in cmdbuf */
	char finaltoken[CONFIG_SYS_CBSIZE];
	char *str = cmdbuf;
	char *argv[CONFIG_SYS_MAXARGS + 1];	/* NULL terminated	*/
	int argc, inquotes;
	int repeatable = 1;
	int rc = 0;

#ifdef DEBUG_PARSER
	printf ("[RUN_COMMAND] cmd[%p]=\"", cmd);
	puts (cmd ? cmd : "NULL");	/* use puts - string may be loooong */
	puts ("\"\n");
#endif

	clear_ctrlc();		/* forget any previous Control C */

	if (!cmd || !*cmd) {
		return -1;	/* empty command */
	}

	if (strlen(cmd) >= CONFIG_SYS_CBSIZE) {
		puts ("## Command too long!\n");
		return -1;
	}

	strcpy (cmdbuf, cmd);

	/* Process separators and check for invalid
	 * repeatable commands
	 */

#ifdef DEBUG_PARSER
	printf ("[PROCESS_SEPARATORS] %s\n", cmd);
#endif
	while (*str) {

		/*
		 * Find separator, or string end
		 * Allow simple escape of ';' by writing "\;"
		 */
		for (inquotes = 0, sep = str; *sep; sep++) {
			if ((*sep=='\'') &&
			    (*(sep-1) != '\\'))
				inquotes=!inquotes;

			if (!inquotes &&
			    (*sep == ';') &&	/* separator		*/
			    ( sep != str) &&	/* past string start	*/
			    (*(sep-1) != '\\'))	/* and NOT escaped	*/
				break;
		}

		/*
		 * Limit the token to data between separators
		 */
		token = str;
		if (*sep) {
			str = sep + 1;	/* start of command for next pass */
			*sep = '\0';
		}
		else
			str = sep;	/* no more commands for next pass */
#ifdef DEBUG_PARSER
		printf ("token: \"%s\"\n", token);
#endif

		/* find macros in this token and replace them */
		process_macros (token, finaltoken);

		/* Extract arguments */
		if ((argc = parse_line (finaltoken, argv)) == 0) {
			rc = -1;	/* no command at all */
			continue;
		}

		if (cmd_process(flag, argc, argv, &repeatable))
			rc = -1;

		/* Did the user stop this? */
		if (had_ctrlc ())
			return -1;	/* if stopped then not repeatable */
	}

	return rc ? rc : repeatable;
}
#endif

/*
 * Run a command using the selected parser.
 *
 * @param cmd	Command to run
 * @param flag	Execution flags (CMD_FLAG_...)
 * @return 0 on success, or != 0 on error.
 */
int run_command(const char *cmd, int flag)
{
#ifndef CONFIG_SYS_HUSH_PARSER
	/*
	 * builtin_run_command can return 0 or 1 for success, so clean up
	 * its result.
	 */
	if (builtin_run_command(cmd, flag) == -1)
		return 1;

	return 0;
#else
	return parse_string_outer(cmd,
			FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP);
#endif
}

#ifndef CONFIG_SYS_HUSH_PARSER
/**
 * Execute a list of command separated by ; or \n using the built-in parser.
 *
 * This function cannot take a const char * for the command, since if it
 * finds newlines in the string, it replaces them with \0.
 *
 * @param cmd	String containing list of commands
 * @param flag	Execution flags (CMD_FLAG_...)
 * @return 0 on success, or != 0 on error.
 */
static int builtin_run_command_list(char *cmd, int flag)
{
	char *line, *next;
	int rcode = 0;

	/*
	 * Break into individual lines, and execute each line; terminate on
	 * error.
	 */
	line = next = cmd;
	while (*next) {
		if (*next == '\n') {
			*next = '\0';
			/* run only non-empty commands */
			if (*line) {
				debug("** exec: \"%s\"\n", line);
				if (builtin_run_command(line, 0) < 0) {
					rcode = 1;
					break;
				}
			}
			line = next + 1;
		}
		++next;
	}
	if (rcode == 0 && *line)
		rcode = (builtin_run_command(line, 0) >= 0);

	return rcode;
}
#endif

int run_command_list(const char *cmd, int len, int flag)
{
	int need_buff = 1;
	char *buff = (char *)cmd;	/* cast away const */
	int rcode = 0;

	if (len == -1) {
		len = strlen(cmd);
#ifdef CONFIG_SYS_HUSH_PARSER
		/* hush will never change our string */
		need_buff = 0;
#else
		/* the built-in parser will change our string if it sees \n */
		need_buff = strchr(cmd, '\n') != NULL;
#endif
	}
	if (need_buff) {
		buff = malloc(len + 1);
		if (!buff)
			return 1;
		memcpy(buff, cmd, len);
		buff[len] = '\0';
	}
#ifdef CONFIG_SYS_HUSH_PARSER
	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
#else
	/*
	 * This function will overwrite any \n it sees with a \0, which
	 * is why it can't work with a const char *. Here we are making
	 * using of internal knowledge of this function, to avoid always
	 * doing a malloc() which is actually required only in a case that
	 * is pretty rare.
	 */
	rcode = builtin_run_command_list(buff, flag);
	if (need_buff)
		free(buff);
#endif

	return rcode;
}

/****************************************************************************/

#if defined(CONFIG_CMD_RUN)
int do_run (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
	int i;

	if (argc < 2)
		return CMD_RET_USAGE;

	for (i=1; i<argc; ++i) {
		char *arg;

		if ((arg = getenv (argv[i])) == NULL) {
			printf ("## Error: \"%s\" not defined\n", argv[i]);
			return 1;
		}

		if (run_command(arg, flag) != 0)
			return 1;
	}
	return 0;
}
#endif