hush.c

shell-HHARM9200.rar 华恒 AT91rm9200 中Busybox shell的源代码

	return rcode;
}

/* built-in 'cd <path>' handler */
static int builtin_cd(struct child_prog *child)
{
	char *newdir;
	if (child->argv[1] == NULL)
		newdir = getenv("HOME");
	else
		newdir = child->argv[1];
	if (chdir(newdir)) {
		printf("cd: %s: %s\n", newdir, strerror(errno));
		return EXIT_FAILURE;
	}
	set_cwd();
	return EXIT_SUCCESS;
}

/* built-in 'env' handler */
static int builtin_env(struct child_prog *dummy)
{
	char **e = environ;
	if (e == NULL) return EXIT_FAILURE;
	for (; *e; e++) {
		puts(*e);
	}
	return EXIT_SUCCESS;
}

/* built-in 'exec' handler */
static int builtin_exec(struct child_prog *child)
{
	if (child->argv[1] == NULL)
		return EXIT_SUCCESS;   /* Really? */
	child->argv++;
	pseudo_exec(child);
	/* never returns */
}

/* built-in 'exit' handler */
static int builtin_exit(struct child_prog *child)
{
	if (child->argv[1] == NULL)
		exit(last_return_code);
	exit (atoi(child->argv[1]));
}

/* built-in 'export VAR=value' handler */
static int builtin_export(struct child_prog *child)
{
	int res = 0;
	char *name = child->argv[1];

	if (name == NULL) {
		return (builtin_env(child));
	}

	name = strdup(name);

	if(name) {
		char *value = strchr(name, '=');

		if (!value) {
			char *tmp;
			/* They are exporting something without an =VALUE */

			value = get_local_var(name);
			if (value) {
				size_t ln = strlen(name);

				tmp = realloc(name, ln+strlen(value)+2);
				if(tmp==NULL)
					res = -1;
				else {
					sprintf(tmp+ln, "=%s", value);
					name = tmp;
				}
			} else {
				/* bash does not return an error when trying to export
				 * an undefined variable.  Do likewise. */
				res = 1;
			}
		}
	}
	if (res<0)
		bb_perror_msg("export");
	else if(res==0)
		res = set_local_var(name, 1);
	else
		res = 0;
	free(name);
	return res;
}

/* built-in 'fg' and 'bg' handler */
static int builtin_fg_bg(struct child_prog *child)
{
	int i, jobnum;
	struct pipe *pi=NULL;

	if (!interactive)
		return EXIT_FAILURE;
	/* If they gave us no args, assume they want the last backgrounded task */
	if (!child->argv[1]) {
		for (pi = job_list; pi; pi = pi->next) {
			if (pi->jobid == last_jobid) {
				break;
			}
		}
		if (!pi) {
			bb_error_msg("%s: no current job", child->argv[0]);
			return EXIT_FAILURE;
		}
	} else {
		if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
			bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
			return EXIT_FAILURE;
		}
		for (pi = job_list; pi; pi = pi->next) {
			if (pi->jobid == jobnum) {
				break;
			}
		}
		if (!pi) {
			bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
			return EXIT_FAILURE;
		}
	}

	if (*child->argv[0] == 'f') {
		/* Put the job into the foreground.  */
		tcsetpgrp(shell_terminal, pi->pgrp);
	}

	/* Restart the processes in the job */
	for (i = 0; i < pi->num_progs; i++)
		pi->progs[i].is_stopped = 0;

	if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
		if (i == ESRCH) {
			remove_bg_job(pi);
		} else {
			bb_perror_msg("kill (SIGCONT)");
		}
	}

	pi->stopped_progs = 0;
	return EXIT_SUCCESS;
}

/* built-in 'help' handler */
static int builtin_help(struct child_prog *dummy)
{
	struct built_in_command *x;

	printf("\nBuilt-in commands:\n");
	printf("-------------------\n");
	for (x = bltins; x->cmd; x++) {
		if (x->descr==NULL)
			continue;
		printf("%s\t%s\n", x->cmd, x->descr);
	}
	printf("\n\n");
	return EXIT_SUCCESS;
}

/* built-in 'jobs' handler */
static int builtin_jobs(struct child_prog *child)
{
	struct pipe *job;
	char *status_string;

	for (job = job_list; job; job = job->next) {
		if (job->running_progs == job->stopped_progs)
			status_string = "Stopped";
		else
			status_string = "Running";

		printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
	}
	return EXIT_SUCCESS;
}


/* built-in 'pwd' handler */
static int builtin_pwd(struct child_prog *dummy)
{
	puts(set_cwd());
	return EXIT_SUCCESS;
}

/* built-in 'read VAR' handler */
static int builtin_read(struct child_prog *child)
{
	int res;

	if (child->argv[1]) {
		char string[BUFSIZ];
		char *var = 0;

		string[0] = 0;  /* In case stdin has only EOF */
		/* read string */
		fgets(string, sizeof(string), stdin);
		chomp(string);
		var = malloc(strlen(child->argv[1])+strlen(string)+2);
		if(var) {
			sprintf(var, "%s=%s", child->argv[1], string);
			res = set_local_var(var, 0);
		} else
			res = -1;
		if (res)
			fprintf(stderr, "read: %m\n");
		free(var);      /* So not move up to avoid breaking errno */
		return res;
	} else {
		do res=getchar(); while(res!='\n' && res!=EOF);
		return 0;
	}
}

/* built-in 'set VAR=value' handler */
static int builtin_set(struct child_prog *child)
{
	char *temp = child->argv[1];
	struct variables *e;

	if (temp == NULL)
		for(e = top_vars; e; e=e->next)
			printf("%s=%s\n", e->name, e->value);
	else
		set_local_var(temp, 0);

		return EXIT_SUCCESS;
}


/* Built-in 'shift' handler */
static int builtin_shift(struct child_prog *child)
{
	int n=1;
	if (child->argv[1]) {
		n=atoi(child->argv[1]);
	}
	if (n>=0 && n<global_argc) {
		/* XXX This probably breaks $0 */
		global_argc -= n;
		global_argv += n;
		return EXIT_SUCCESS;
	} else {
		return EXIT_FAILURE;
	}
}

/* Built-in '.' handler (read-in and execute commands from file) */
static int builtin_source(struct child_prog *child)
{
	FILE *input;
	int status;

	if (child->argv[1] == NULL)
		return EXIT_FAILURE;

	/* XXX search through $PATH is missing */
	input = fopen(child->argv[1], "r");
	if (!input) {
		bb_error_msg("Couldn't open file '%s'", child->argv[1]);
		return EXIT_FAILURE;
	}

	/* Now run the file */
	/* XXX argv and argc are broken; need to save old global_argv
	 * (pointer only is OK!) on this stack frame,
	 * set global_argv=child->argv+1, recurse, and restore. */
	mark_open(fileno(input));
	status = parse_file_outer(input);
	mark_closed(fileno(input));
	fclose(input);
	return (status);
}

static int builtin_umask(struct child_prog *child)
{
	mode_t new_umask;
	const char *arg = child->argv[1];
	char *end;
	if (arg) {
		new_umask=strtoul(arg, &end, 8);
		if (*end!='\0' || end == arg) {
			return EXIT_FAILURE;
		}
	} else {
		printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
	}
	umask(new_umask);
	return EXIT_SUCCESS;
}

/* built-in 'unset VAR' handler */
static int builtin_unset(struct child_prog *child)
{
	/* bash returned already true */
	unset_local_var(child->argv[1]);
	return EXIT_SUCCESS;
}

static int builtin_not_written(struct child_prog *child)
{
	printf("builtin_%s not written\n",child->argv[0]);
	return EXIT_FAILURE;
}

static int b_check_space(o_string *o, int len)
{
	/* It would be easy to drop a more restrictive policy
	 * in here, such as setting a maximum string length */
	if (o->length + len > o->maxlen) {
		char *old_data = o->data;
		/* assert (data == NULL || o->maxlen != 0); */
		o->maxlen += max(2*len, B_CHUNK);
		o->data = realloc(o->data, 1 + o->maxlen);
		if (o->data == NULL) {
			free(old_data);
		}
	}
	return o->data == NULL;
}

static int b_addchr(o_string *o, int ch)
{
	debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
	if (b_check_space(o, 1)) return B_NOSPAC;
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
	return 0;
}

static void b_reset(o_string *o)
{
	o->length = 0;
	o->nonnull = 0;
	if (o->data != NULL) *o->data = '\0';
}

static void b_free(o_string *o)
{
	b_reset(o);
	free(o->data);
	o->data = NULL;
	o->maxlen = 0;
}

/* My analysis of quoting semantics tells me that state information
 * is associated with a destination, not a source.
 */
static int b_addqchr(o_string *o, int ch, int quote)
{
	if (quote && strchr("*?[\\",ch)) {
		int rc;
		rc = b_addchr(o, '\\');
		if (rc) return rc;
	}
	return b_addchr(o, ch);
}

/* belongs in utility.c */
char *simple_itoa(unsigned int i)
{
	/* 21 digits plus null terminator, good for 64-bit or smaller ints */
	static char local[22];
	char *p = &local[21];
	*p-- = '\0';
	do {
		*p-- = '0' + i % 10;
		i /= 10;
	} while (i > 0);
	return p + 1;
}

static int b_adduint(o_string *o, unsigned int i)
{
	int r;
	char *p = simple_itoa(i);
	/* no escape checking necessary */
	do r=b_addchr(o, *p++); while (r==0 && *p);
	return r;
}

static int static_get(struct in_str *i)
{
	int ch=*i->p++;
	if (ch=='\0') return EOF;
	return ch;
}

static int static_peek(struct in_str *i)
{
	return *i->p;
}

static inline void cmdedit_set_initial_prompt(void)
{
#ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
	PS1 = NULL;
#else
	PS1 = getenv("PS1");
	if(PS1==0)
		PS1 = "\\w \\$ ";
#endif
}

static inline void setup_prompt_string(int promptmode, char **prompt_str)
{
	debug_printf("setup_prompt_string %d ",promptmode);
#ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
	/* Set up the prompt */
	if (promptmode == 1) {
		free(PS1);
		PS1=xmalloc(strlen(cwd)+4);
		sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
		*prompt_str = PS1;
	} else {
		*prompt_str = PS2;
	}
#else
	*prompt_str = (promptmode==1)? PS1 : PS2;
#endif
	debug_printf("result %s\n",*prompt_str);
}

static void get_user_input(struct in_str *i)
{
	char *prompt_str;
	static char the_command[BUFSIZ];

	setup_prompt_string(i->promptmode, &prompt_str);
#ifdef CONFIG_FEATURE_COMMAND_EDITING
	/*
	 ** enable command line editing only while a command line
	 ** is actually being read; otherwise, we'll end up bequeathing
	 ** atexit() handlers and other unwanted stuff to our
	 ** child processes ([e-mail])
	 */
	cmdedit_read_input(prompt_str, the_command);
#else
	fputs(prompt_str, stdout);
	fflush(stdout);
	the_command[0]=fgetc(i->file);
	the_command[1]='\0';
#endif
	fflush(stdout);
	i->p = the_command;
}

/* This is the magic location that prints prompts
 * and gets data back from the user */
static int file_get(struct in_str *i)
{
	int ch;

	ch = 0;
	/* If there is data waiting, eat it up */
	if (i->p && *i->p) {
		ch=*i->p++;
	} else {