wordexp.c

Axis 221 camera embedded programing interface

			if (free_value && value)
				free(value);

			if (!colon_seen && value)
				/* Substitute NULL */
				goto success;

			value = pattern ? strdup(pattern) : pattern;
			free_value = 1;

			if (pattern && !value)
				goto no_space;

			break;

		case ACT_NONNULL_SUBST:
			if (value && (*value || !colon_seen)) {
				if (free_value && value)
					free(value);

				value = pattern ? strdup(pattern) : pattern;
				free_value = 1;

				if (pattern && !value)
					goto no_space;

				break;
			}

			/* Substitute NULL */
			if (free_value)
				free(value);
			goto success;

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

			if (!colon_seen && value) {
				/* Substitute NULL */
				if (free_value)
					free(value);
				goto success;
			}

			if (free_value && value)
				free(value);

			value = pattern ? strdup(pattern) : pattern;
			free_value = 1;

			if (pattern && !value)
				goto no_space;

			setenv(env, value, 1);
			break;

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

	free(env);
	env = NULL;
	free(pattern);
	pattern = NULL;

	if (seen_hash) {
		char param_length[21];

		param_length[20] = '\0';
		*word = w_addstr(*word, word_length, max_length,
						 _itoa(value ? strlen(value) : 0,
									&param_length[20]));
		if (free_value) {
			assert(value != NULL);
			free(value);
		}

		return *word ? 0 : WRDE_NOSPACE;
	}

	if (value == NULL)
		return 0;

	if (quoted || !pwordexp) {
		/* Quoted - no field split */
		*word = w_addstr(*word, word_length, max_length, value);
		if (free_value)
			free(value);

		return *word ? 0 : WRDE_NOSPACE;
	} else {
		/* Need to field-split */
		char *value_copy = strdup(value);	/* Don't modify value */
		char *field_begin = value_copy;
		int seen_nonws_ifs = 0;

		if (free_value)
			free(value);

		if (value_copy == NULL)
			goto no_space;

		do {
			char *field_end = field_begin;
			char *next_field;

			/* If this isn't the first field, start a new word */
			if (field_begin != value_copy) {
				if (w_addword(pwordexp, *word) == WRDE_NOSPACE) {
					free(value_copy);
					goto no_space;
				}

				*word = w_newword(word_length, max_length);
			}

			/* Skip IFS whitespace before the field */
			field_begin += strspn(field_begin, ifs_white);

			if (!seen_nonws_ifs && *field_begin == 0)
				/* Nothing but whitespace */
				break;

			/* Search for the end of the field */
			field_end = field_begin + strcspn(field_begin, ifs);

			/* Set up pointer to the character after end of field and
			   skip whitespace IFS after it. */
			next_field = field_end + strspn(field_end, ifs_white);

			/* Skip at most one non-whitespace IFS character after the field */
			seen_nonws_ifs = 0;
			if (*next_field && strchr(ifs, *next_field)) {
				seen_nonws_ifs = 1;
				next_field++;
			}

			/* Null-terminate it */
			*field_end = 0;

			/* Tag a copy onto the current word */
			*word = w_addstr(*word, word_length, max_length, field_begin);

			if (*word == NULL && *field_begin != '\0') {
				free(value_copy);
				goto no_space;
			}

			field_begin = next_field;
		}
		while (seen_nonws_ifs || *field_begin);

		free(value_copy);
	}

	return 0;

  success:
	error = 0;
	goto do_error;

  no_space:
	error = WRDE_NOSPACE;
	goto do_error;

  syntax:
	error = WRDE_SYNTAX;

  do_error:
	if (env)
		free(env);

	if (pattern)
		free(pattern);

	return error;
}
#else
static inline int
parse_backtick(char **word, size_t * word_length, size_t * max_length,
			   const char *words, size_t * offset, int flags,
			   wordexp_t * pwordexp, const char *ifs,
			   const char *ifs_white)
{
	return 0;
}
#endif

static int
parse_dollars(char **word, size_t * word_length, size_t * max_length,
			  const char *words, size_t * offset, int flags,
			  wordexp_t * pwordexp, const char *ifs, const char *ifs_white,
			  int quoted)
{
	/* We are poised _at_ "$" */
	switch (words[1 + *offset]) {
	case '"':
	case '\'':
	case 0:
		*word = w_addchar(*word, word_length, max_length, '$');
		return *word ? 0 : WRDE_NOSPACE;

#ifdef __WORDEXP_FULL
	case '(':
		if (words[2 + *offset] == '(') {
			/* Differentiate between $((1+3)) and $((echo);(ls)) */
			int i = 3 + *offset;
			int depth = 0;

			while (words[i] && !(depth == 0 && words[i] == ')')) {
				if (words[i] == '(')
					++depth;
				else if (words[i] == ')')
					--depth;

				++i;
			}

			if (words[i] == ')' && words[i + 1] == ')') {
				(*offset) += 3;
				/* Call parse_arith -- 0 is for "no brackets" */
				return parse_arith(word, word_length, max_length, words,
								   offset, flags, 0);
			}
		}

		if (flags & WRDE_NOCMD)
			return WRDE_CMDSUB;

		(*offset) += 2;
		return parse_comm(word, word_length, max_length, words, offset,
						  flags, quoted ? NULL : pwordexp, ifs, ifs_white);

	case '[':
		(*offset) += 2;
		/* Call parse_arith -- 1 is for "brackets" */
		return parse_arith(word, word_length, max_length, words, offset,
						   flags, 1);

	case '{':
	default:
		++(*offset);			/* parse_param needs to know if "{" is there */
		return parse_param(word, word_length, max_length, words, offset,
						   flags, pwordexp, ifs, ifs_white, quoted);
#else
	default:
		++(*offset);			/* parse_param needs to know if "{" is there */
		return 0;
#endif
	}
}

static int
parse_dquote(char **word, size_t * word_length, size_t * max_length,
			 const char *words, size_t * offset, int flags,
			 wordexp_t * pwordexp, const char *ifs, const char *ifs_white)
{
	/* We are poised just after a double-quote */
	int error;

	for (; words[*offset]; ++(*offset)) {
		switch (words[*offset]) {
		case '"':
			return 0;

		case '$':
			error = parse_dollars(word, word_length, max_length, words, offset,
							  flags, pwordexp, ifs, ifs_white, 1);
			/* The ``1'' here is to tell parse_dollars not to
			 * split the fields.  It may need to, however ("$@").
			 */
			if (error)
				return error;

			break;

		case '`':
			if (flags & WRDE_NOCMD)
				return WRDE_CMDSUB;

			++(*offset);
			error = parse_backtick(word, word_length, max_length, words,
								   offset, flags, NULL, NULL, NULL);
			/* The first NULL here is to tell parse_backtick not to
			 * split the fields.
			 */
			if (error)
				return error;

			break;

		case '\\':
			error = parse_qtd_backslash(word, word_length, max_length, words,
									offset);

			if (error)
				return error;

			break;

		default:
			*word = w_addchar(*word, word_length, max_length, words[*offset]);
			if (*word == NULL)
				return WRDE_NOSPACE;
		}
	}

	/* Unterminated string */
	return WRDE_SYNTAX;
}

/*
 * wordfree() is to be called after pwordexp is finished with.
 */

void wordfree(wordexp_t * pwordexp)
{

	/* wordexp can set pwordexp to NULL */
	if (pwordexp && pwordexp->we_wordv) {
		char **wordv = pwordexp->we_wordv;

		for (wordv += pwordexp->we_offs; *wordv; ++wordv)
			free(*wordv);

		free(pwordexp->we_wordv);
		pwordexp->we_wordv = NULL;
	}
}

/*
 * wordexp()
 */

int wordexp(const char *words, wordexp_t * we, int flags)
{
	size_t words_offset;
	size_t word_length;
	size_t max_length;
	char *word = w_newword(&word_length, &max_length);
	int error;
	char *ifs;
	char ifs_white[4];
	wordexp_t old_word = *we;

	if (flags & WRDE_REUSE) {
		/* Minimal implementation of WRDE_REUSE for now */
		wordfree(we);
		old_word.we_wordv = NULL;
	}

	if ((flags & WRDE_APPEND) == 0) {
		we->we_wordc = 0;

		if (flags & WRDE_DOOFFS) {
			we->we_wordv = calloc(1 + we->we_offs, sizeof(char *));
			if (we->we_wordv == NULL) {
				error = WRDE_NOSPACE;
				goto do_error;
			}
		} else {
			we->we_wordv = calloc(1, sizeof(char *));
			if (we->we_wordv == NULL) {
				error = WRDE_NOSPACE;
				goto do_error;
			}

			we->we_offs = 0;
		}
	}

	/* Find out what the field separators are.
	 * There are two types: whitespace and non-whitespace.
	 */
	ifs = getenv("IFS");

	if (!ifs)
		/* IFS unset - use <space><tab><newline>. */
		ifs = strcpy(ifs_white, " \t\n");
	else {
		char *ifsch = ifs;
		char *whch = ifs_white;

		/* Start off with no whitespace IFS characters */
		ifs_white[0] = '\0';

		while (*ifsch != '\0') {
			if ((*ifsch == ' ') || (*ifsch == '\t') || (*ifsch == '\n')) {
				/* Whitespace IFS.  See first whether it is already in our
				   collection.  */
				char *runp = ifs_white;

				while (runp < whch && *runp != '\0' && *runp != *ifsch)
					++runp;

				if (runp == whch)
					*whch++ = *ifsch;
			}

			++ifsch;
		}
		*whch = '\0';
	}

	for (words_offset = 0; words[words_offset]; ++words_offset)
		switch (words[words_offset]) {
		case '\\':
			error = parse_backslash(&word, &word_length, &max_length, words,
								&words_offset);

			if (error)
				goto do_error;

			break;

		case '$':
			error = parse_dollars(&word, &word_length, &max_length, words,
								  &words_offset, flags, we, ifs, ifs_white,
								  0);

			if (error)
				goto do_error;

			break;

		case '`':
			if (flags & WRDE_NOCMD) {
				error = WRDE_CMDSUB;
				goto do_error;
			}

			++words_offset;
			error = parse_backtick(&word, &word_length, &max_length, words,
								   &words_offset, flags, we, ifs,
								   ifs_white);

			if (error)
				goto do_error;

			break;

		case '"':
			++words_offset;
			error = parse_dquote(&word, &word_length, &max_length, words,
								 &words_offset, flags, we, ifs, ifs_white);

			if (error)
				goto do_error;

			if (!word_length) {
				error = w_addword(we, NULL);

				if (error)
					return error;
			}

			break;

		case '\'':
			++words_offset;
			error = parse_squote(&word, &word_length, &max_length, words,
								 &words_offset);

			if (error)
				goto do_error;

			if (!word_length) {
				error = w_addword(we, NULL);

				if (error)
					return error;
			}

			break;

		case '~':
			error = parse_tilde(&word, &word_length, &max_length, words,
								&words_offset, we->we_wordc);

			if (error)
				goto do_error;

			break;

		case '*':
		case '[':
		case '?':
			error = parse_glob(&word, &word_length, &max_length, words,
							   &words_offset, flags, we, ifs, ifs_white);

			if (error)
				goto do_error;

			break;

		default:
			/* Is it a word separator? */
			if (strchr(" \t", words[words_offset]) == NULL) {
				char ch = words[words_offset];

				/* Not a word separator -- but is it a valid word char? */
				if (strchr("\n|&;<>(){}", ch)) {
					/* Fail */
					error = WRDE_BADCHAR;
					goto do_error;
				}

				/* "Ordinary" character -- add it to word */
				word = w_addchar(word, &word_length, &max_length, ch);
				if (word == NULL) {
					error = WRDE_NOSPACE;
					goto do_error;
				}

				break;
			}

			/* If a word has been delimited, add it to the list. */
			if (word != NULL) {
				error = w_addword(we, word);
				if (error)
					goto do_error;
			}

			word = w_newword(&word_length, &max_length);
		}

	/* End of string */

	/* There was a word separator at the end */
	if (word == NULL)			/* i.e. w_newword */
		return 0;

	/* There was no field separator at the end */
	return w_addword(we, word);

  do_error:
	/* Error:
	 *  free memory used (unless error is WRDE_NOSPACE), and
	 *  set we members back to what they were.
	 */

	if (word != NULL)
		free(word);

	if (error == WRDE_NOSPACE)
		return WRDE_NOSPACE;

	if ((flags & WRDE_APPEND) == 0)
		wordfree(we);

	*we = old_word;
	return error;
}