wordexp.c

Axis 221 camera embedded programing interface

	};
	size_t env_length;
	size_t env_maxlen;
	size_t pat_length;
	size_t pat_maxlen;
	size_t start = *offset;
	char *env;
	char *pattern;
	char *value = NULL;
	enum action action = ACT_NONE;
	int depth = 0;
	int colon_seen = 0;
	int seen_hash = 0;
	int free_value = 0;
	int pattern_is_quoted = 0;	/* 1 for singly-quoted, 2 for doubly-quoted */
	int error;
	int special = 0;
	char buffer[21];
	int brace = words[*offset] == '{';

	env = w_newword(&env_length, &env_maxlen);
	pattern = w_newword(&pat_length, &pat_maxlen);

	if (brace)
		++ * offset;

	/* First collect the parameter name. */

	if (words[*offset] == '#') {
		seen_hash = 1;
		if (!brace)
			goto envsubst;
		++*offset;
	}

	if (isalpha(words[*offset]) || words[*offset] == '_') {
		/* Normal parameter name. */
		do {
			env = w_addchar(env, &env_length, &env_maxlen, words[*offset]);
			if (env == NULL)
				goto no_space;
		}
		while (isalnum(words[++*offset]) || words[*offset] == '_');
	} else if (isdigit(words[*offset])) {
		/* Numeric parameter name. */
		special = 1;
		do {
			env = w_addchar(env, &env_length, &env_maxlen, words[*offset]);
			if (env == NULL)
				goto no_space;
			if (!brace)
				goto envsubst;
		}
		while (isdigit(words[++*offset]));
	} else if (strchr("*@$", words[*offset]) != NULL) {
		/* Special parameter. */
		special = 1;
		env = w_addchar(env, &env_length, &env_maxlen, words[*offset]);
		if (env == NULL)
			goto no_space;
		++*offset;
	} else {
		if (brace)
			goto syntax;
	}

	if (brace) {
		/* Check for special action to be applied to the value. */
		switch (words[*offset]) {
		case '}':
			/* Evaluate. */
			goto envsubst;

		case '#':
			action = ACT_RP_SHORT_LEFT;
			if (words[1 + *offset] == '#') {
				++*offset;
				action = ACT_RP_LONG_LEFT;
			}
			break;

		case '%':
			action = ACT_RP_SHORT_RIGHT;
			if (words[1 + *offset] == '%') {
				++*offset;
				action = ACT_RP_LONG_RIGHT;
			}
			break;

		case ':':
			if (strchr("-=?+", words[1 + *offset]) == NULL)
				goto syntax;

			colon_seen = 1;
			action = words[++*offset];
			break;

		case '-':
		case '=':
		case '?':
		case '+':
			action = words[*offset];
			break;

		default:
			goto syntax;
		}

		/* Now collect the pattern, but don't expand it yet. */
		++*offset;
		for (; words[*offset]; ++(*offset)) {
			switch (words[*offset]) {
			case '{':
				if (!pattern_is_quoted)
					++depth;
				break;

			case '}':
				if (!pattern_is_quoted) {
					if (depth == 0)
						goto envsubst;
					--depth;
				}
				break;

			case '\\':
				if (pattern_is_quoted)
					/* Quoted; treat as normal character. */
					break;

				/* Otherwise, it's an escape: next character is literal. */
				if (words[++*offset] == '\0')
					goto syntax;

				pattern = w_addchar(pattern, &pat_length, &pat_maxlen, '\\');
				if (pattern == NULL)
					goto no_space;

				break;

			case '\'':
				if (pattern_is_quoted == 0)
					pattern_is_quoted = 1;
				else if (pattern_is_quoted == 1)
					pattern_is_quoted = 0;

				break;

			case '"':
				if (pattern_is_quoted == 0)
					pattern_is_quoted = 2;
				else if (pattern_is_quoted == 2)
					pattern_is_quoted = 0;

				break;
			}

			pattern = w_addchar(pattern, &pat_length, &pat_maxlen,
								words[*offset]);
			if (pattern == NULL)
				goto no_space;
		}
	}

	/* End of input string -- remember to reparse the character that we
	 * stopped at.  */
	--(*offset);

  envsubst:
	if (words[start] == '{' && words[*offset] != '}')
		goto syntax;

	if (env == NULL) {
		if (seen_hash) {
			/* $# expands to the number of positional parameters */
			buffer[20] = '\0';
			value = _itoa(__libc_argc - 1, &buffer[20]);
			seen_hash = 0;
		} else {
			/* Just $ on its own */
			*offset = start - 1;
			*word = w_addchar(*word, word_length, max_length, '$');
			return *word ? 0 : WRDE_NOSPACE;
		}
	}
	/* Is it a numeric parameter? */
	else if (isdigit(env[0])) {
		int n = atoi(env);

		if (n >= __libc_argc)
			/* Substitute NULL. */
			value = NULL;
		else
			/* Replace with appropriate positional parameter. */
			value = __libc_argv[n];
	}
	/* Is it a special parameter? */
	else if (special) {
		/* Is it `$$'? */
		if (*env == '$') {
			buffer[20] = '\0';
			value = _itoa(getpid(), &buffer[20]);
		}
		/* Is it `${#*}' or `${#@}'? */
		else if ((*env == '*' || *env == '@') && seen_hash) {
			buffer[20] = '\0';
			value = _itoa(__libc_argc > 0 ? __libc_argc - 1 : 0,
							   &buffer[20]);
			*word = w_addstr(*word, word_length, max_length, value);
			free(env);
			if (pattern)
				free(pattern);
			return *word ? 0 : WRDE_NOSPACE;
		}
		/* Is it `$*' or `$@' (unquoted) ? */
		else if (*env == '*' || (*env == '@' && !quoted)) {
			size_t plist_len = 0;
			int p;
			char *end;

			/* Build up value parameter by parameter (copy them) */
			for (p = 1; __libc_argv[p]; ++p)
				plist_len += strlen(__libc_argv[p]) + 1;	/* for space */
			value = malloc(plist_len);
			if (value == NULL)
				goto no_space;
			end = value;
			*end = 0;
			for (p = 1; __libc_argv[p]; ++p) {
				if (p > 1)
					*end++ = ' ';
				end = stpcpy(end, __libc_argv[p]);
			}

			free_value = 1;
		} else {
			/* Must be a quoted `$@' */
			assert(*env == '@' && quoted);

			/* Each parameter is a separate word ("$@") */
			if (__libc_argc == 2)
				value = __libc_argv[1];
			else if (__libc_argc > 2) {
				int p;

				/* Append first parameter to current word. */
				value = w_addstr(*word, word_length, max_length,
								 __libc_argv[1]);
				if (value == NULL || w_addword(pwordexp, value))
					goto no_space;

				for (p = 2; __libc_argv[p + 1]; p++) {
					char *newword = strdup(__libc_argv[p]);

					if (newword == NULL || w_addword(pwordexp, newword))
						goto no_space;
				}

				/* Start a new word with the last parameter. */
				*word = w_newword(word_length, max_length);
				value = __libc_argv[p];
			} else {
				free(env);
				free(pattern);
				return 0;
			}
		}
	} else
		value = getenv(env);

	if (value == NULL && (flags & WRDE_UNDEF)) {
		/* Variable not defined. */
		error = WRDE_BADVAL;
		goto do_error;
	}

	if (action != ACT_NONE) {
		int expand_pattern = 0;

		/* First, find out if we need to expand pattern (i.e. if we will
		 * use it). */
		switch (action) {
		case ACT_RP_SHORT_LEFT:
		case ACT_RP_LONG_LEFT:
		case ACT_RP_SHORT_RIGHT:
		case ACT_RP_LONG_RIGHT:
			/* Always expand for these. */
			expand_pattern = 1;
			break;

		case ACT_NULL_ERROR:
		case ACT_NULL_SUBST:
		case ACT_NULL_ASSIGN:
			if (!value || (!*value && colon_seen))
				/* If param is unset, or set but null and a colon has been seen,
				   the expansion of the pattern will be needed. */
				expand_pattern = 1;

			break;

		case ACT_NONNULL_SUBST:
			/* Expansion of word will be needed if parameter is set and not null,
			   or set null but no colon has been seen. */
			if (value && (*value || !colon_seen))
				expand_pattern = 1;

			break;

		default:
			assert(!"Unrecognised action!");
		}

		if (expand_pattern) {
			/* We need to perform tilde expansion, parameter expansion,
			   command substitution, and arithmetic expansion.  We also
			   have to be a bit careful with wildcard characters, as
			   pattern might be given to fnmatch soon.  To do this, we
			   convert quotes to escapes. */

			char *expanded;
			size_t exp_len;
			size_t exp_maxl;
			char *p;
			int quoted = 0;		/* 1: single quotes; 2: double */

			expanded = w_newword(&exp_len, &exp_maxl);
			for (p = pattern; p && *p; p++) {
				size_t offset;

				switch (*p) {
				case '"':
					if (quoted == 2)
						quoted = 0;
					else if (quoted == 0)
						quoted = 2;
					else
						break;

					continue;

				case '\'':
					if (quoted == 1)
						quoted = 0;
					else if (quoted == 0)
						quoted = 1;
					else
						break;

					continue;

				case '*':
				case '?':
					if (quoted) {
						/* Convert quoted wildchar to escaped wildchar. */
						expanded = w_addchar(expanded, &exp_len,
											 &exp_maxl, '\\');

						if (expanded == NULL)
							goto no_space;
					}
					break;

				case '$':
					offset = 0;
					error = parse_dollars(&expanded, &exp_len, &exp_maxl, p,
									  &offset, flags, NULL, NULL, NULL, 1);
					if (error) {
						if (free_value)
							free(value);

						if (expanded)
							free(expanded);

						goto do_error;
					}

					p += offset;
					continue;

				case '~':
					if (quoted || exp_len)
						break;

					offset = 0;
					error = parse_tilde(&expanded, &exp_len, &exp_maxl, p,
										&offset, 0);
					if (error) {
						if (free_value)
							free(value);

						if (expanded)
							free(expanded);

						goto do_error;
					}

					p += offset;
					continue;

				case '\\':
					expanded = w_addchar(expanded, &exp_len, &exp_maxl, '\\');
					++p;
					assert(*p);	/* checked when extracted initially */
					if (expanded == NULL)
						goto no_space;
				}

				expanded = w_addchar(expanded, &exp_len, &exp_maxl, *p);

				if (expanded == NULL)
					goto no_space;
			}

			if (pattern)
				free(pattern);

			pattern = expanded;
		}

		switch (action) {
		case ACT_RP_SHORT_LEFT:
		case ACT_RP_LONG_LEFT:
		case ACT_RP_SHORT_RIGHT:
		case ACT_RP_LONG_RIGHT:
		{
			char *p;
			char c;
			char *end;

			if (value == NULL || pattern == NULL || *pattern == '\0')
				break;

			end = value + strlen(value);

			switch (action) {
			case ACT_RP_SHORT_LEFT:
				for (p = value; p <= end; ++p) {
					c = *p;
					*p = '\0';
					if (fnmatch(pattern, value, 0) != FNM_NOMATCH) {
						*p = c;
						if (free_value) {
							char *newval = strdup(p);

							if (newval == NULL) {
								free(value);
								goto no_space;
							}
							free(value);
							value = newval;
						} else
							value = p;
						break;
					}
					*p = c;
				}

				break;

			case ACT_RP_LONG_LEFT:
				for (p = end; p >= value; --p) {
					c = *p;
					*p = '\0';
					if (fnmatch(pattern, value, 0) != FNM_NOMATCH) {
						*p = c;
						if (free_value) {
							char *newval = strdup(p);

							if (newval == NULL) {
								free(value);
								goto no_space;
							}
							free(value);
							value = newval;
						} else
							value = p;
						break;
					}
					*p = c;
				}

				break;

			case ACT_RP_SHORT_RIGHT:
				for (p = end; p >= value; --p) {
					if (fnmatch(pattern, p, 0) != FNM_NOMATCH) {
						char *newval;

						newval = malloc(p - value + 1);

						if (newval == NULL) {
							if (free_value)
								free(value);
							goto no_space;
						}

						*(char *) mempcpy(newval, value, p - value) = '\0';
						if (free_value)
							free(value);
						value = newval;
						free_value = 1;
						break;
					}
				}

				break;

			case ACT_RP_LONG_RIGHT:
				for (p = value; p <= end; ++p) {
					if (fnmatch(pattern, p, 0) != FNM_NOMATCH) {
						char *newval;

						newval = malloc(p - value + 1);

						if (newval == NULL) {
							if (free_value)
								free(value);
							goto no_space;
						}

						*(char *) mempcpy(newval, value, p - value) = '\0';
						if (free_value)
							free(value);
						value = newval;
						free_value = 1;
						break;
					}
				}

				break;

			default:
				break;
			}

			break;
		}

		case ACT_NULL_ERROR:
			if (value && *value)
				/* Substitute parameter */
				break;

			error = 0;
			if (!colon_seen && value)
				/* Substitute NULL */
				;
			else if (*pattern)
				fprintf(stderr, "%s: %s\n", env, pattern);
			else {
				fprintf(stderr, "%s: parameter null or not set\n", env);
				error = WRDE_BADVAL;
			}

			if (free_value)
				free(value);
			goto do_error;

		case ACT_NULL_SUBST:
			if (value && *value)
				/* Substitute parameter */
				break;