dpkg.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

}

/*
 * Create one new node and one new edge for every dependency.
 */
void add_split_dependencies(common_node_t *parent_node, const char *whole_line, unsigned int edge_type)
{
	char *line = xstrdup(whole_line);
	char *line2;
	char *line_ptr1 = NULL;
	char *line_ptr2 = NULL;
	char *field;
	char *field2;
	char *version;
	edge_t *edge;
	int offset_ch;
	int type;

	field = strtok_r(line, ",", &line_ptr1);
	do {
		line2 = xstrdup(field);
		field2 = strtok_r(line2, "|", &line_ptr2);
		if ((edge_type == EDGE_DEPENDS) && (strcmp(field, field2) != 0)) {
			type = EDGE_OR_DEPENDS;
		}
		else if ((edge_type == EDGE_PRE_DEPENDS) && (strcmp(field, field2) != 0)) {
			type = EDGE_OR_PRE_DEPENDS;
		} else {
			type = edge_type;
		}

		do {
			edge = (edge_t *) xmalloc(sizeof(edge_t));
			edge->type = type;

			/* Skip any extra leading spaces */
			field2 += strspn(field2, " ");

			/* Get dependency version info */
			version = strchr(field2, '(');
			if (version == NULL) {
				edge->operator = VER_ANY;
				/* Get the versions hash number, adding it if the number isnt already in there */
				edge->version = search_name_hashtable("ANY");
			} else {
				/* Skip leading ' ' or '(' */
				version += strspn(field2, " ");
				version += strspn(version, "(");
				/* Calculate length of any operator charactors */
				offset_ch = strspn(version, "<=>");
				/* Determine operator */
				if (offset_ch > 0) {
					if (strncmp(version, "=", offset_ch) == 0) {
						edge->operator = VER_EQUAL;
					}
					else if (strncmp(version, "<<", offset_ch) == 0) {
						edge->operator = VER_LESS;
					}
					else if (strncmp(version, "<=", offset_ch) == 0) {
						edge->operator = VER_LESS_EQUAL;
					}
					else if (strncmp(version, ">>", offset_ch) == 0) {
						edge->operator = VER_MORE;
					}
					else if (strncmp(version, ">=", offset_ch) == 0) {
						edge->operator = VER_MORE_EQUAL;
					} else {
						error_msg_and_die("Illegal operator\n");
					}
				}
				/* skip to start of version numbers */
				version += offset_ch;
				version += strspn(version, " ");

				/* Truncate version at trailing ' ' or ')' */
				version[strcspn(version, " )")] = '\0';
				/* Get the versions hash number, adding it if the number isnt already in there */
				edge->version = search_name_hashtable(version);
			}

			/* Get the dependency name */
			field2[strcspn(field2, " (")] = '\0';
			edge->name = search_name_hashtable(field2);
	
			/* link the new edge to the current node */
			parent_node->num_of_edges++;
			parent_node->edge = xrealloc(parent_node->edge, sizeof(edge_t) * (parent_node->num_of_edges + 1));
			parent_node->edge[parent_node->num_of_edges - 1] = edge;
		} while ((field2 = strtok_r(NULL, "|", &line_ptr2)) != NULL);
		free(line2);
	} while ((field = strtok_r(NULL, ",", &line_ptr1)) != NULL);
	free(line);

	return;
}

void free_package(common_node_t *node)
{
	unsigned short i;
	if (node) {
		for (i = 0; i < node->num_of_edges; i++) {
			if (node->edge[i]) {
				free(node->edge[i]);
			}
		}
		if (node->edge) {
			free(node->edge);
		}
		free(node);
	}
}

unsigned int fill_package_struct(char *control_buffer)
{
	common_node_t *new_node = (common_node_t *) xcalloc(1, sizeof(common_node_t));

	char *field_name;
	char *field_value;
	int field_start = 0;
	int num = -1;
	int buffer_length = strlen(control_buffer);

	new_node->version = search_name_hashtable("unknown");
	while (field_start < buffer_length) {
		field_start += read_package_field(&control_buffer[field_start],
				&field_name, &field_value);

		if (field_name == NULL) {
			goto fill_package_struct_cleanup; // Oh no, the dreaded goto statement !!
		}

		if (strcmp(field_name, "Package") == 0) {
			new_node->name = search_name_hashtable(field_value);
		}
		else if (strcmp(field_name, "Version") == 0) {
			new_node->version = search_name_hashtable(field_value);
		}
		else if (strcmp(field_name, "Pre-Depends") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_PRE_DEPENDS);
		}
		else if (strcmp(field_name, "Depends") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_DEPENDS);
		}
		else if (strcmp(field_name, "Replaces") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_REPLACES);
		}
		else if (strcmp(field_name, "Provides") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_PROVIDES);
		}
		else if (strcmp(field_name, "Conflicts") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_CONFLICTS);
		}
		else if (strcmp(field_name, "Suggests") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_SUGGESTS);
		}
		else if (strcmp(field_name, "Recommends") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_RECOMMENDS);
		}
		else if (strcmp(field_name, "Enhances") == 0) {
			add_split_dependencies(new_node, field_value, EDGE_ENHANCES);
		}
fill_package_struct_cleanup:
		if (field_name) {
			free(field_name);
		}
		if (field_value) {
			free(field_value);
		}
	}

	if (new_node->version == search_name_hashtable("unknown")) {
		free_package(new_node);
		return(-1);
	}
	num = search_package_hashtable(new_node->name, new_node->version, VER_EQUAL);
	if (package_hashtable[num] == NULL) {
		package_hashtable[num] = new_node;
	} else {
		free_package(new_node);
	}
	return(num);
}

/* if num = 1, it returns the want status, 2 returns flag, 3 returns status */
unsigned int get_status(const unsigned int status_node, const int num)
{
	char *status_string = name_hashtable[status_hashtable[status_node]->status];
	char *state_sub_string;
	unsigned int state_sub_num;
	int len;
	int i;

	/* set tmp_string to point to the start of the word number */
	for (i = 1; i < num; i++) {
		/* skip past a word */
		status_string += strcspn(status_string, " ");
		/* skip past the seperating spaces */
		status_string += strspn(status_string, " ");
	}
	len = strcspn(status_string, " \n\0");
	state_sub_string = xstrndup(status_string, len);
	state_sub_num = search_name_hashtable(state_sub_string);
	free(state_sub_string);
	return(state_sub_num);
}

void set_status(const unsigned int status_node_num, const char *new_value, const int position)
{
	const unsigned int new_value_len = strlen(new_value);
	const unsigned int new_value_num = search_name_hashtable(new_value);
	unsigned int want = get_status(status_node_num, 1);
	unsigned int flag = get_status(status_node_num, 2);
	unsigned int status = get_status(status_node_num, 3);
	int want_len = strlen(name_hashtable[want]);
	int flag_len = strlen(name_hashtable[flag]);
	int status_len = strlen(name_hashtable[status]);
	char *new_status;

	switch (position) {
		case (1):
			want = new_value_num;
			want_len = new_value_len;
			break;
		case (2):
			flag = new_value_num;
			flag_len = new_value_len;
			break;
		case (3):
			status = new_value_num;
			status_len = new_value_len;
			break;
		default:
			error_msg_and_die("DEBUG ONLY: this shouldnt happen");
	}

	new_status = (char *) xmalloc(want_len + flag_len + status_len + 3);
	sprintf(new_status, "%s %s %s", name_hashtable[want], name_hashtable[flag], name_hashtable[status]);
	status_hashtable[status_node_num]->status = search_name_hashtable(new_status);
	free(new_status);
	return;
}

void index_status_file(const char *filename)
{
	FILE *status_file;
	char *control_buffer;
	char *status_line;
	status_node_t *status_node = NULL;
	unsigned int status_num;

	status_file = xfopen(filename, "r");
	while ((control_buffer = fgets_str(status_file, "\n\n")) != NULL) {
		const unsigned int package_num = fill_package_struct(control_buffer);
		if (package_num != -1) {
			status_node = xmalloc(sizeof(status_node_t));
			/* fill_package_struct doesnt handle the status field */
			status_line = strstr(control_buffer, "Status:");
			if (status_line != NULL) {
				status_line += 7;
				status_line += strspn(status_line, " \n\t");
				status_line = xstrndup(status_line, strcspn(status_line, "\n\0"));
				status_node->status = search_name_hashtable(status_line);
				free(status_line);
			}
			status_node->package = package_num;
			status_num = search_status_hashtable(name_hashtable[package_hashtable[status_node->package]->name]);
			status_hashtable[status_num] = status_node;
		}
		free(control_buffer);
	}
	fclose(status_file);
	return;
}


char *get_depends_field(common_node_t *package, const int depends_type)
{
	char *depends = NULL;
	char *old_sep = (char *)xcalloc(1, 3);
	char *new_sep = (char *)xcalloc(1, 3);
	int line_size = 0;
	int depends_size;

	int i;

	for (i = 0; i < package->num_of_edges; i++) {
		if ((package->edge[i]->type == EDGE_OR_PRE_DEPENDS) ||
			(package->edge[i]->type == EDGE_OR_DEPENDS)) {
		}

		if ((package->edge[i]->type == depends_type) ||
			(package->edge[i]->type == depends_type + 1)) {
			/* Check if its the first time through */

			depends_size = 8 + strlen(name_hashtable[package->edge[i]->name])
				+ strlen(name_hashtable[package->edge[i]->version]);
			line_size += depends_size;
			depends = (char *) xrealloc(depends, line_size + 1);

			/* Check to see if this dependency is the type we are looking for
			 * +1 to check for 'extra' types, e.g. ored dependecies */
			strcpy(old_sep, new_sep);
			if (package->edge[i]->type == depends_type) {
				strcpy(new_sep, ", ");
			}
			else if (package->edge[i]->type == depends_type + 1) {
				strcpy(new_sep, "| ");
			}

			if (depends_size == line_size) {
				strcpy(depends, "");
			} else {
				if ((strcmp(old_sep, "| ") == 0) && (strcmp(new_sep, "| ") == 0)) {
					strcat(depends, " | ");
				} else {
					strcat(depends, ", ");
				}
			}

			strcat(depends, name_hashtable[package->edge[i]->name]);
			if (strcmp(name_hashtable[package->edge[i]->version], "NULL") != 0) {
				if (package->edge[i]->operator == VER_EQUAL) {
					strcat(depends, " (= ");
				}
				else if (package->edge[i]->operator == VER_LESS) {
					strcat(depends, " (<< ");
				}
				else if (package->edge[i]->operator == VER_LESS_EQUAL) {
					strcat(depends, " (<= ");
				}
				else if (package->edge[i]->operator == VER_MORE) {
					strcat(depends, " (>> ");
				}
				else if (package->edge[i]->operator == VER_MORE_EQUAL) {
					strcat(depends, " (>= ");
				} else {
					strcat(depends, " (");
				}
				strcat(depends, name_hashtable[package->edge[i]->version]);
				strcat(depends, ")");
			}
		}
	}
	return(depends);
}

void write_buffer_no_status(FILE *new_status_file, const char *control_buffer)
{
	char *name;
	char *value;
	int start = 0;
	while (1) {
		start += read_package_field(&control_buffer[start], &name, &value);
		if (name == NULL) {
			break;
		}
		if (strcmp(name, "Status") != 0) {
			fprintf(new_status_file, "%s: %s\n", name, value);
		}
	}
	return;
}

/* This could do with a cleanup */
void write_status_file(deb_file_t **deb_file)
{
	FILE *old_status_file = xfopen("/var/lib/dpkg/status", "r");
	FILE *new_status_file = xfopen("/var/lib/dpkg/status.udeb", "w");
	char *package_name;
	char *status_from_file;
	char *control_buffer = NULL;
	char *tmp_string;
	int status_num;
	int field_start = 0;
	int write_flag;
	int i = 0;

	/* Update previously known packages */
	while ((control_buffer = fgets_str(old_status_file, "\n\n")) != NULL) {
		if ((tmp_string = strstr(control_buffer, "Package:")) == NULL) {
			continue;
		}

		tmp_string += 8;
 		tmp_string += strspn(tmp_string, " \n\t");
		package_name = xstrndup(tmp_string, strcspn(tmp_string, "\n\0"));
		write_flag = FALSE;
		tmp_string = strstr(control_buffer, "Status:");
		if (tmp_string != NULL) {
			/* Seperate the status value from the control buffer */
			tmp_string += 7;