Erlang 从URL中截取尾部文件名

分析项目edownloader时看到的代码：

从 “http://www.aaaa.com.cn/download/bbb/ccc.exe” 中截取ccc.exe

uri.hrl
-record(uri, {scheme, %% "http", "ftp" user_info="", %% [] | "srp" host="", %% "somewhere.net" port="", %% [] | 80 | 8080 path="", %% "/here/there/everytwhere" raw_query="", %% "id=12345&name=fred+johnson". undecoded. frag="", %% "some anchor" raw %% original raw uri }).
uri.erl

from_string(Uri) -> %{http,ELS} {Scheme, Uri1} = parse_scheme(Uri), %{www.xxx.com:port,ELS} {Authority, Uri2} = parse_authority(Uri1), %{[],"www.xxx.com:port"} {UserInfo, HostPort} = parse_user_info(Authority), %{www.xxx.com,port} {Host, Port} = parse_host_port(HostPort), % {Path, Uri3} = parse_path(Uri2), {Query, Uri4} = parse_query(Uri3), Frag = parse_frag(Uri4), new(Scheme, UserInfo, Host, Port, Path, Query, Frag, Uri). %http parse_scheme(Uri) -> parse_scheme(Uri, []). parse_scheme([$: | Uri], Acc) -> {lists:reverse(Acc), Uri}; parse_scheme([], Acc) -> {[], lists:reverse(Acc)}; parse_scheme([C | Rest], Acc) -> parse_scheme(Rest, [C | Acc]). parse_authority("//" ++ Uri) -> parse_authority(Uri, ""); parse_authority(Uri) -> Uri. %www.xxx.com parse_authority([$/ | Rest], Acc) -> {lists:reverse(Acc), [$/ | Rest]}; parse_authority([], Acc) -> {lists:reverse(Acc), []}; parse_authority([C | Rest], Acc) -> parse_authority(Rest, [C | Acc]). parse_user_info(Authority) -> parse_user_info(Authority, []). parse_user_info([$@ | HostPort], Acc) -> {lists:reverse(Acc), HostPort}; parse_user_info([], Acc) -> {[], lists:reverse(Acc)}; parse_user_info([C | HostPort], Acc) -> parse_user_info(HostPort, [C | Acc]). parse_host_port(HostPort) -> case string:tokens(HostPort, ":") of [Host] -> {Host, ""}; [Host, Port] -> {Host, list_to_integer(Port)}; _ -> throw({uri_error, {invalid_host_port, HostPort}}) end. parse_path(Uri) -> parse_path(Uri, []). parse_path([C | Uri], Acc) when C == $?; C == $# -> {lists:reverse(Acc), [C | Uri]}; parse_path([], Acc) -> {lists:reverse(Acc), ""}; parse_path([C | Uri], Acc) -> parse_path(Uri, [C | Acc]). parse_query([$? | Uri]) -> parse_query(Uri, []); parse_query(Uri) -> {"", Uri}. parse_query([$# | Uri], Acc) -> {lists:reverse(Acc), [$# | Uri]}; parse_query([], Acc) -> {lists:reverse(Acc), ""}; parse_query([C | Rest], Acc) -> parse_query(Rest, [C | Acc]). parse_frag([$# | Frag]) -> unquote(Frag); parse_frag("") -> ""; parse_frag(Data) -> throw({uri_error, {data_left_after_parsing, Data}}). new(Scheme, UserInfo, Host, Port, Path, Query, Frag, Uri) -> update_raw(#uri{scheme = Scheme, user_info = unquote(UserInfo), host = Host, port = Port, path = unquote(Path), raw_query = Query, frag = unquote(Frag), raw = Uri}). new(Scheme, UserInfo, Host, Port, Path, Query, Frag) -> update_raw(#uri{scheme = Scheme, user_info = unquote(UserInfo), host = Host, port = Port, path = unquote(Path), raw_query = Query, frag = unquote(Frag)}). update_raw(Uri) -> Uri#uri{raw = iolist_to_string(to_iolist(Uri))}. iolist_to_string(Str) -> binary_to_list(iolist_to_binary(Str)). unquote(Str) -> unquote(Str, []). unquote([], Acc) -> lists:reverse(Acc); unquote([$+ | Str], Acc) -> unquote(Str, [$ | Acc]); unquote([$\%, A, B | Str], Acc) -> unquote(Str, [erlang:list_to_integer([A, B], 16) | Acc]); unquote([C | Str], Acc) -> unquote(Str, [C | Acc]).

 

edownload_util.erl

filename_from_uri(Uri) when is_list(Uri) -> filename_from_uri(uri:from_string(Uri)); filename_from_uri(Uri) when is_record(Uri, uri) -> Path = Uri#uri.path %, {match, Start, Len} = regexp:match(Path, "([^/]+){1}quot;) , {match, [{Start, Len},_]} = re:run(Path, "([^/]+){1}quot;) , string:substr(Path, Start+1, Len) .
3> edownload_util:filename_from_uri("http://www.baidu.com/download/emessager.apk").
结果："emessager.apk"