hush.c

		case '\\':
			if (next == EOF) {
				syntax();
				return 1;
			}
			b_addqchr(dest, '\\', dest->quote);
			b_addqchr(dest, b_getch(input), dest->quote);
			break;
		case '$':
			if (handle_dollar(dest, ctx, input)!=0) return 1;
			break;
		case '\'':
			dest->nonnull = 1;
			while(ch=b_getch(input),ch!=EOF && ch!='\'') {
#ifdef __U_BOOT__
				if(input->__promptme == 0) return 1;
#endif
				b_addchr(dest,ch);
			}
			if (ch==EOF) {
				syntax();
				return 1;
			}
			break;
		case '"':
			dest->nonnull = 1;
			dest->quote = !dest->quote;
			break;
#ifndef __U_BOOT__
		case '`':
			process_command_subs(dest, ctx, input, '`');
			break;
		case '>':
			redir_fd = redirect_opt_num(dest);
			done_word(dest, ctx);
			redir_style=REDIRECT_OVERWRITE;
			if (next == '>') {
				redir_style=REDIRECT_APPEND;
				b_getch(input);
			} else if (next == '(') {
				syntax();   /* until we support >(list) Process Substitution */
				return 1;
			}
			setup_redirect(ctx, redir_fd, redir_style, input);
			break;
		case '<':
			redir_fd = redirect_opt_num(dest);
			done_word(dest, ctx);
			redir_style=REDIRECT_INPUT;
			if (next == '<') {
				redir_style=REDIRECT_HEREIS;
				b_getch(input);
			} else if (next == '>') {
				redir_style=REDIRECT_IO;
				b_getch(input);
			} else if (next == '(') {
				syntax();   /* until we support <(list) Process Substitution */
				return 1;
			}
			setup_redirect(ctx, redir_fd, redir_style, input);
			break;
#endif
		case ';':
			done_word(dest, ctx);
			done_pipe(ctx,PIPE_SEQ);
			break;
		case '&':
			done_word(dest, ctx);
			if (next=='&') {
				b_getch(input);
				done_pipe(ctx,PIPE_AND);
			} else {
#ifndef __U_BOOT__
				done_pipe(ctx,PIPE_BG);
#else
				syntax_err();
				return 1;
#endif
			}
			break;
		case '|':
			done_word(dest, ctx);
			if (next=='|') {
				b_getch(input);
				done_pipe(ctx,PIPE_OR);
			} else {
				/* we could pick up a file descriptor choice here
				 * with redirect_opt_num(), but bash doesn't do it.
				 * "echo foo 2| cat" yields "foo 2". */
#ifndef __U_BOOT__
				done_command(ctx);
#else
				syntax_err();
				return 1;
#endif
			}
			break;
#ifndef __U_BOOT__
		case '(':
		case '{':
			if (parse_group(dest, ctx, input, ch)!=0) return 1;
			break;
		case ')':
		case '}':
			syntax();   /* Proper use of this character caught by end_trigger */
			return 1;
			break;
#endif
		default:
			syntax();   /* this is really an internal logic error */
			return 1;
			}
		}
	}
	/* complain if quote?  No, maybe we just finished a command substitution
	 * that was quoted.  Example:
	 * $ echo "`cat foo` plus more"
	 * and we just got the EOF generated by the subshell that ran "cat foo"
	 * The only real complaint is if we got an EOF when end_trigger != '\0',
	 * that is, we were really supposed to get end_trigger, and never got
	 * one before the EOF.  Can't use the standard "syntax error" return code,
	 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
	debug_printf("leaving parse_stream (EOF)\n");
	if (end_trigger != '\0') return -1;
	return 0;
}

void mapset(const unsigned char *set, int code)
{
	const unsigned char *s;
	for (s=set; *s; s++) map[*s] = code;
}

void update_ifs_map(void)
{
	/* char *ifs and char map[256] are both globals. */
	ifs = getenv("IFS");
	if (ifs == NULL) ifs=" \t\n";
	/* Precompute a list of 'flow through' behavior so it can be treated
	 * quickly up front.  Computation is necessary because of IFS.
	 * Special case handling of IFS == " \t\n" is not implemented.
	 * The map[] array only really needs two bits each, and on most machines
	 * that would be faster because of the reduced L1 cache footprint.
	 */
	memset(map,0,sizeof(map)); /* most characters flow through always */
#ifndef __U_BOOT__
	mapset("\\$'\"`", 3);      /* never flow through */
	mapset("<>;&|(){}#", 1);   /* flow through if quoted */
#else
	mapset("\\$'\"", 3);       /* never flow through */
	mapset(";&|#", 1);         /* flow through if quoted */
#endif
	mapset(ifs, 2);            /* also flow through if quoted */
}

/* most recursion does not come through here, the exeception is
 * from builtin_source() */
int parse_stream_outer(struct in_str *inp, int flag)
{

	struct p_context ctx;
	o_string temp=NULL_O_STRING;
	int rcode;
#ifdef __U_BOOT__
	int code = 0;
#endif
	do {
		ctx.type = flag;
		initialize_context(&ctx);
		update_ifs_map();
		if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
		inp->promptmode=1;
		rcode = parse_stream(&temp, &ctx, inp, '\n');
#ifdef __U_BOOT__
		if (rcode == 1) flag_repeat = 0;
#endif
		if (rcode != 1 && ctx.old_flag != 0) {
			syntax();
#ifdef __U_BOOT__
			flag_repeat = 0;
#endif
		}
		if (rcode != 1 && ctx.old_flag == 0) {
			done_word(&temp, &ctx);
			done_pipe(&ctx,PIPE_SEQ);
#ifndef __U_BOOT__
			run_list(ctx.list_head);
#else
			code = run_list(ctx.list_head);
			if (code == -2) {	/* exit */
				b_free(&temp);
				code = 0;
				/* XXX hackish way to not allow exit from main loop */
				if (inp->peek == file_peek) {
					printf("exit not allowed from main input shell.\n");
					continue;
				}
				break;
			}
			if (code == -1)
			    flag_repeat = 0;
#endif
		} else {
			if (ctx.old_flag != 0) {
				free(ctx.stack);
				b_reset(&temp);
			}
#ifdef __U_BOOT__
			if (inp->__promptme == 0) printf("<INTERRUPT>\n");
			inp->__promptme = 1;
#endif
			temp.nonnull = 0;
			temp.quote = 0;
			inp->p = NULL;
			free_pipe_list(ctx.list_head,0);
		}
		b_free(&temp);
	} while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
#ifndef __U_BOOT__
	return 0;
#else
	return (code != 0) ? 1 : 0;
#endif /* __U_BOOT__ */
}

#ifndef __U_BOOT__
static int parse_string_outer(const char *s, int flag)
#else
int parse_string_outer(char *s, int flag)
#endif	/* __U_BOOT__ */
{
	struct in_str input;
#ifdef __U_BOOT__
	char *p = NULL;
	int rcode;
	if ( !s || !*s)
		return 1;
	if (!(p = strchr(s, '\n')) || *++p) {
		p = xmalloc(strlen(s) + 2);
		strcpy(p, s);
		strcat(p, "\n");
		setup_string_in_str(&input, p);
		rcode = parse_stream_outer(&input, flag);
		free(p);
		return rcode;
	} else {
#endif
	setup_string_in_str(&input, s);
	return parse_stream_outer(&input, flag);
#ifdef __U_BOOT__
	}
#endif
}

#ifndef __U_BOOT__
static int parse_file_outer(FILE *f)
#else
int parse_file_outer(void)
#endif
{
	int rcode;
	struct in_str input;
#ifndef __U_BOOT__
	setup_file_in_str(&input, f);
#else
	setup_file_in_str(&input);
#endif
	rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
	return rcode;
}

#ifdef __U_BOOT__
static void u_boot_hush_reloc(void)
{
	DECLARE_GLOBAL_DATA_PTR;
	unsigned long addr;
	struct reserved_combo *r;

	for (r=reserved_list; r<reserved_list+NRES; r++) {
		addr = (ulong) (r->literal) + gd->reloc_off;
		r->literal = (char *)addr;
	}
}

int u_boot_hush_start(void)
{
	if (top_vars == NULL) {
		top_vars = malloc(sizeof(struct variables));
		top_vars->name = "HUSH_VERSION";
		top_vars->value = "0.01";
		top_vars->next = 0;
		top_vars->flg_export = 0;
		top_vars->flg_read_only = 1;
		u_boot_hush_reloc();
	}
	return 0;
}

static void *xmalloc(size_t size)
{
	void *p = NULL;

	if (!(p = malloc(size))) {
	    printf("ERROR : memory not allocated\n");
	    for(;;);
	}
	return p;
}

static void *xrealloc(void *ptr, size_t size)
{
	void *p = NULL;

	if (!(p = realloc(ptr, size))) {
	    printf("ERROR : memory not allocated\n");
	    for(;;);
	}
	return p;
}
#endif /* __U_BOOT__ */

#ifndef __U_BOOT__
/* Make sure we have a controlling tty.  If we get started under a job
 * aware app (like bash for example), make sure we are now in charge so
 * we don't fight over who gets the foreground */
static void setup_job_control(void)
{
	static pid_t shell_pgrp;
	/* Loop until we are in the foreground.  */
	while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
		kill (- shell_pgrp, SIGTTIN);

	/* Ignore interactive and job-control signals.  */
	signal(SIGINT, SIG_IGN);
	signal(SIGQUIT, SIG_IGN);
	signal(SIGTERM, SIG_IGN);
	signal(SIGTSTP, SIG_IGN);
	signal(SIGTTIN, SIG_IGN);
	signal(SIGTTOU, SIG_IGN);
	signal(SIGCHLD, SIG_IGN);

	/* Put ourselves in our own process group.  */
	setsid();
	shell_pgrp = getpid ();
	setpgid (shell_pgrp, shell_pgrp);

	/* Grab control of the terminal.  */
	tcsetpgrp(shell_terminal, shell_pgrp);
}

int hush_main(int argc, char **argv)
{
	int opt;
	FILE *input;
	char **e = environ;

	/* XXX what should these be while sourcing /etc/profile? */
	global_argc = argc;
	global_argv = argv;

	/* (re?) initialize globals.  Sometimes hush_main() ends up calling
	 * hush_main(), therefore we cannot rely on the BSS to zero out this
	 * stuff.  Reset these to 0 every time. */
	ifs = NULL;
	/* map[] is taken care of with call to update_ifs_map() */
	fake_mode = 0;
	interactive = 0;
	close_me_head = NULL;
	last_bg_pid = 0;
	job_list = NULL;
	last_jobid = 0;

	/* Initialize some more globals to non-zero values */
	set_cwd();
#ifdef CONFIG_FEATURE_COMMAND_EDITING
	cmdedit_set_initial_prompt();
#else
	PS1 = NULL;
#endif
	PS2 = "> ";

	/* initialize our shell local variables with the values
	 * currently living in the environment */
	if (e) {
		for (; *e; e++)
			set_local_var(*e, 2);   /* without call putenv() */
	}

	last_return_code=EXIT_SUCCESS;


	if (argv[0] && argv[0][0] == '-') {
		debug_printf("\nsourcing /etc/profile\n");
		if ((input = fopen("/etc/profile", "r")) != NULL) {
			mark_open(fileno(input));
			parse_file_outer(input);
			mark_closed(fileno(input));
			fclose(input);
		}
	}
	input=stdin;

	while ((opt = getopt(argc, argv, "c:xif")) > 0) {
		switch (opt) {
			case 'c':
				{
					global_argv = argv+optind;
					global_argc = argc-optind;
					opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
					goto final_return;
				}
				break;
			case 'i':
				interactive++;
				break;
			case 'f':
				fake_mode++;
				break;
			default:
#ifndef BB_VER
				fprintf(stderr, "Usage: sh [FILE]...\n"
						"   or: sh -c command [args]...\n\n");
				exit(EXIT_FAILURE);
#else
				show_usage();
#endif
		}
	}
	/* A shell is interactive if the `-i' flag was given, or if all of
	 * the following conditions are met:
	 *	  no -c command
	 *    no arguments remaining or the -s flag given
	 *    standard input is a terminal
	 *    standard output is a terminal
	 *    Refer to Posix.2, the description of the `sh' utility. */
	if (argv[optind]==NULL && input==stdin &&
			isatty(fileno(stdin)) && isatty(fileno(stdout))) {
		interactive++;
	}

	debug_printf("\ninteractive=%d\n", interactive);
	if (interactive) {
		/* Looks like they want an interactive shell */
#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
		printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
		printf( "Enter 'help' for a list of built-in commands.\n\n");
#endif
		setup_job_control();
	}

	if (argv[optind]==NULL) {
		opt=parse_file_outer(stdin);
		goto final_return;
	}

	debug_printf("\nrunning script '%s'\n", argv[optind]);
	global_argv = argv+optind;
	global_argc = argc-optind;
	input = xfopen(argv[optind], "r");
	opt = parse_file_outer(input);

#ifdef CONFIG_FEATURE_CLEAN_UP
	fclose(input);
	if (cwd && cwd != unknown)
		free((char*)cwd);
	{
		struct variables *cur, *tmp;
		for(cur = top_vars; cur; cur = tmp) {
			tmp = cur->next;
			if (!cur->flg_read_only) {
				free(cur->name);
				free(cur->value);
				free(cur);
			}
		}
	}
#endif

final_return:
	return(opt?opt:last_return_code);
}
#endif

static char *insert_var_value(char *inp)
{
	int res_str_len = 0;
	int len;
	int done = 0;
	char *p, *p1, *res_str = NULL;

	while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
		if (p != inp) {
			len = p - inp;
			res_str = xrealloc(res_str, (res_str_len + len));
			strncpy((res_str + res_str_len), inp, len);
			res_str_len += len;
		}
		inp = ++p;
		p = strchr(inp, SPECIAL_VAR_SYMBOL);
		*p = '\0';
		if ((p1 = lookup_param(inp))) {
			len = res_str_len + strlen(p1);
			res_str = xrealloc(res_str, (1 + len));
			strcpy((res_str + res_str_len), p1);
			res_str_len = len;
		}
		*p = SPECIAL_VAR_SYMBOL;
		inp = ++p;
		done = 1;
	}
	if (done) {
		res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
		strcpy((res_str + res_str_len), inp);
		while ((p = strchr(res_str, '\n'))) {
			*p = ' ';
		}
	}
	return (res_str == NULL) ? inp : res_str;
}

static char **make_list_in(char **inp, char *name)
{
	int len, i;
	int name_len = strlen(name);
	int n = 0;
	char **list;
	char *p1, *p2, *p3;

	/* create list of variable values */
	list = xmalloc(sizeof(*list));
	for (i = 0; inp[i]; i++) {
		p3 = insert_var_value(inp[i]);
		p1 = p3;
		while (*p1) {
			if ((*p1 == ' ')) {
				p1++;
				continue;
			}
			if ((p2 = strchr(p1, ' '))) {
				len = p2 - p1;
			} else {
				len = strlen(p1);
				p2 = p1 + len;
			}
			/* we use n + 2 in realloc for list,because we add
			 * new element and then we will add NULL element */
			list = xrealloc(list, sizeof(*list) * (n + 2));
			list[n] = xmalloc(2 + name_len + len);
			strcpy(list[n], name);
			strcat(list[n], "=");
			strncat(list[n], p1, len);
			list[n++][name_len + len + 1] = '\0';
			p1 = p2;
		}
		if (p3 != inp[i]) free(p3);
	}
	list[n] = NULL;
	return list;
}

/* Make new string for parser */
static char * make_string(char ** inp)
{
	char *p;
	char *str = NULL;
	int n;
	int len = 2;

	for (n = 0; inp[n]; n++) {
		p = insert_var_value(inp[n]);
		str = xrealloc(str, (len + strlen(p)));
		if (n) {
			strcat(str, " ");
		} else {
			*str = '\0';
		}
		strcat(str, p);
		len = strlen(str) + 3;
		if (p != inp[n]) free(p);
	}
	len = strlen(str);
	*(str + len) = '\n';
	*(str + len + 1) = '\0';
	return str;
}

#endif /* CFG_HUSH_PARSER */
/****************************************************************************/