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diff --git a/src/terminal-regex.hh b/src/terminal-regex.hh new file mode 100644 index 0000000..6fcc0f9 --- /dev/null +++ b/src/terminal-regex.hh @@ -0,0 +1,158 @@ +/* + * Copyright © 2015 Egmont Koblinger + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* + * Mini style-guide: + * + * #define'd fragments should preferably have an outermost group, for the + * exact same reason as why usually in C/C++ #define's the values are enclosed + * in parentheses: that is, so that you don't get surprised when you use the + * macro and append a quantifier. + * + * For repeated fragments prefer regex-style (?(DEFINE)(?<NAME>(...))) and use + * as (?&NAME), so that the regex string and the compiled regex object is + * smaller. + * + * Build small blocks, comment and unittest them heavily. + * + * Use free-spacing mode for improved readability. The hardest to read is + * which additional characters belong to a "(?" prefix. To improve + * readability, place a space after this, and for symmetry, before the closing + * parenthesis. Also place a space around "|" characters. No space before + * quantifiers. Try to be consistent with the existing style (yes I know the + * existing style is not consistent either, but please do your best). + * + * See http://www.rexegg.com/regex-disambiguation.html for all the "(?" + * syntaxes. + */ + +#ifndef TERMINAL_REGEX_H +#define TERMINAL_REGEX_H + +/* Lookbehind to see if there's a preceding apostrophe. + * Unlike the other *_DEF macros which define regex subroutines, + * this one is a named capture that defines APOS_START to either + * an apostrophe or the empty string, depending on the character + * preceding this APOS_START_DEF construct. */ +#define APOS_START_DEF "(?<APOS_START>(?<='))?" + +#define SCHEME "(?ix: news | telnet | nntp | https? | ftps? | sftp | webcal )" + +#define USERCHARS "-+.[:alnum:]" +/* Nonempty username, e.g. "john.smith" */ +#define USER "[" USERCHARS "]+" + +#define PASSCHARS_CLASS "[-[:alnum:]\\Q,?;.:/!%$^*&~\"#'\\E]" +/* Optional colon-prefixed password. I guess empty password should be allowed, right? E.g. ":secret", ":", "" */ +#define PASS "(?x: :" PASSCHARS_CLASS "* )?" + +/* Optional at-terminated username (with perhaps a password too), e.g. "joe@", "pete:secret@", "" */ +#define USERPASS "(?:" USER PASS "@)?" + +/* S4: IPv4 segment (number between 0 and 255) with lookahead at the end so that we don't match "25" in the string "256". + The lookahead could go to the last segment of IPv4 only but this construct allows nicer unittesting. */ +#define S4_DEF "(?(DEFINE)(?<S4>(?x: (?: [0-9] | [1-9][0-9] | 1[0-9]{2} | 2[0-4][0-9] | 25[0-5] ) (?! [0-9] ) )))" + +/* IPV4: Decimal IPv4, e.g. "1.2.3.4", with lookahead (implemented in S4) at the end so that we don't match "192.168.1.123" in the string "192.168.1.1234". */ +#define IPV4_DEF S4_DEF "(?(DEFINE)(?<IPV4>(?x: (?: (?&S4) \\. ){3} (?&S4) )))" + +/* IPv6, including embedded IPv4, e.g. "::1", "dead:beef::1.2.3.4". + * Lookahead for the next char not being a dot or digit, so it doesn't get stuck matching "dead:beef::1" in "dead:beef::1.2.3.4". + * This is not required since the surrounding brackets would trigger backtracking, but it allows nicer unittesting. + * TODO: more strict check (right number of colons, etc.) + * TODO: add zone_id: RFC 4007 section 11, RFC 6874 */ + +/* S6: IPv6 segment, S6C: IPv6 segment followed by a comma, CS6: comma followed by an IPv6 segment */ +#define S6_DEF "(?(DEFINE)(?<S6>[[:xdigit:]]{1,4})(?<CS6>:(?&S6))(?<S6C>(?&S6):))" + +/* No :: shorthand */ +#define IPV6_FULL "(?x: (?&S6C){7} (?&S6) )" +/* Begins with :: */ +#define IPV6_LEFT "(?x: : (?&CS6){1,7} )" +/* :: somewhere in the middle - use negative lookahead to make sure there aren't too many colons in total */ +#define IPV6_MID "(?x: (?! (?: [[:xdigit:]]*: ){8} ) (?&S6C){1,6} (?&CS6){1,6} )" +/* Ends with :: */ +#define IPV6_RIGHT "(?x: (?&S6C){1,7} : )" +/* Is "::" and nothing more */ +#define IPV6_NULL "(?x: :: )" + +/* The same ones for IPv4-embedded notation, without the actual IPv4 part */ +#define IPV6V4_FULL "(?x: (?&S6C){6} )" +#define IPV6V4_LEFT "(?x: :: (?&S6C){0,5} )" /* includes "::<ipv4>" */ +#define IPV6V4_MID "(?x: (?! (?: [[:xdigit:]]*: ){7} ) (?&S6C){1,4} (?&CS6){1,4} ) :" +#define IPV6V4_RIGHT "(?x: (?&S6C){1,5} : )" + +/* IPV6: An IPv6 address (possibly with an embedded IPv4). + * This macro defines both IPV4 and IPV6, since the latter one requires the former. */ +#define IP_DEF IPV4_DEF S6_DEF "(?(DEFINE)(?<IPV6>(?x: (?: " IPV6_NULL " | " IPV6_LEFT " | " IPV6_MID " | " IPV6_RIGHT " | " IPV6_FULL " | (?: " IPV6V4_FULL " | " IPV6V4_LEFT " | " IPV6V4_MID " | " IPV6V4_RIGHT " ) (?&IPV4) ) (?! [.:[:xdigit:]] ) )))" + +/* Either an alphanumeric character or dash; or if [negative lookahead] not ASCII + * then any graphical Unicode character. + * A segment can consist entirely of numbers. + * (Note: PCRE doesn't support character class subtraction/intersection.) */ +#define HOSTNAMESEGMENTCHARS_CLASS "(?x: [-[:alnum:]] | (?! [[:ascii:]] ) [[:graph:]] )" + +/* A hostname of at least 1 component. The last component cannot be entirely numbers. + * E.g. "foo", "example.com", "1234.com", but not "foo.123" */ +#define HOSTNAME1 "(?x: (?: " HOSTNAMESEGMENTCHARS_CLASS "+ \\. )* " HOSTNAMESEGMENTCHARS_CLASS "* (?! [0-9] ) " HOSTNAMESEGMENTCHARS_CLASS "+ )" + +/* A hostname of at least 2 components. The last component cannot be entirely numbers. + * E.g. "example.com", "1234.com", but not "1234.56" */ +#define HOSTNAME2 "(?x: (?: " HOSTNAMESEGMENTCHARS_CLASS "+ \\.)+ " HOSTNAME1 " )" + +/* For URL: Hostname, IPv4, or bracket-enclosed IPv6, e.g. "example.com", "1.2.3.4", "[::1]" */ +#define URL_HOST "(?x: " HOSTNAME1 " | (?&IPV4) | \\[ (?&IPV6) \\] )" + +/* For e-mail: Hostname of at least two segments, or bracket-enclosed IPv4 or IPv6, e.g. "example.com", "[1.2.3.4]", "[::1]". + * Technically an e-mail with a single-component hostname might be valid on a local network, but let's avoid tons of false positives (e.g. in a typical shell prompt). */ +#define EMAIL_HOST "(?x: " HOSTNAME2 " | \\[ (?: (?&IPV4) | (?&IPV6) ) \\] )" + +/* Number between 1 and 65535, with lookahead at the end so that we don't match "6789" in the string "67890", + and in turn we don't eventually match "http://host:6789" in "http://host:67890". */ +#define N_1_65535 "(?x: (?: [1-9][0-9]{0,3} | [1-5][0-9]{4} | 6[0-4][0-9]{3} | 65[0-4][0-9]{2} | 655[0-2][0-9] | 6553[0-5] ) (?! [0-9] ) )" + +/* Optional colon-prefixed port, e.g. ":1080", "" */ +#define PORT "(?x: \\:" N_1_65535 " )?" + +/* Omit the parentheses, see below */ +#define PATHCHARS_CLASS "[-[:alnum:]\\Q_$.+!*,:;@&=?/~#|%'\\E]" +/* Chars to end a URL. Apostrophe only allowed if there wasn't one in front of the URL, see bug 448044 */ +#define PATHTERM_CLASS "[-[:alnum:]\\Q_$+*:@&=/~#|%'\\E]" +#define PATHTERM_NOAPOS_CLASS "[-[:alnum:]\\Q_$+*:@&=/~#|%\\E]" + +/* Recursive definition of PATH that allows parentheses and square brackets only if balanced, see bug 763980. */ +#define PATH_INNER_DEF "(?(DEFINE)(?<PATH_INNER>(?x: (?: " PATHCHARS_CLASS "* (?: \\( (?&PATH_INNER) \\) | \\[ (?&PATH_INNER) \\] ) )* " PATHCHARS_CLASS "* )))" +/* Same as above, but the last character (if exists and is not a parenthesis) must be from PATHTERM_CLASS. */ +#define PATH_DEF "(?(DEFINE)(?<PATH>(?x: (?: " PATHCHARS_CLASS "* (?: \\( (?&PATH_INNER) \\) | \\[ (?&PATH_INNER) \\] ) )* (?: " PATHCHARS_CLASS "* (?(<APOS_START>)" PATHTERM_NOAPOS_CLASS "|" PATHTERM_CLASS ") )? )))" + +#define URLPATH "(?x: [/?#](?&PATH) )?" +#define VOIP_PATH "(?x: [;?](?&PATH) )?" + +/* Now let's put these fragments together */ + +#define DEFS APOS_START_DEF IP_DEF PATH_INNER_DEF PATH_DEF + +#define REGEX_URL_AS_IS DEFS SCHEME "://" USERPASS URL_HOST PORT URLPATH +/* TODO: also support file:/etc/passwd */ +#define REGEX_URL_FILE DEFS "(?ix: file:/ (?: / (?: " HOSTNAME1 " )? / )? (?! / ) )(?&PATH)" +/* Lookbehind so that we don't catch "abc.www.foo.bar", bug 739757. Lookahead for www/ftp for convenience (so that we can reuse HOSTNAME1). */ +#define REGEX_URL_HTTP DEFS "(?<!(?:" HOSTNAMESEGMENTCHARS_CLASS "|[.]))(?=(?i:www|ftp))" HOSTNAME1 PORT URLPATH +#define REGEX_URL_VOIP DEFS "(?i:h323:|sips?:)" USERPASS URL_HOST PORT VOIP_PATH +#define REGEX_EMAIL DEFS "(?i:mailto:)?" USER "@" EMAIL_HOST +#define REGEX_NEWS_MAN "(?i:news:|man:|info:)[-[:alnum:]\\Q^_{|}~!\"#$%&'()*+,./;:=?`\\E]+" + +#endif /* !TERMINAL_REGEX_H */ |