diff options
Diffstat (limited to 'bin/title.c')
| -rw-r--r-- | bin/title.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/bin/title.c b/bin/title.c new file mode 100644 index 00000000..82f89d95 --- /dev/null +++ b/bin/title.c @@ -0,0 +1,211 @@ +/* Copyright (C) 2019 C. McEnroe <june@causal.agency> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <curl/curl.h> +#include <err.h> +#include <locale.h> +#include <regex.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sysexits.h> +#include <unistd.h> +#include <wchar.h> + +static regex_t regex(const char *pattern, int flags) { + regex_t regex; + int error = regcomp(®ex, pattern, REG_EXTENDED | flags); + if (!error) return regex; + + char buf[256]; + regerror(error, ®ex, buf, sizeof(buf)); + errx(EX_SOFTWARE, "regcomp: %s: %s", buf, pattern); +} + +static const struct Entity { + wchar_t ch; + const char *name; +} Entities[] = { + { L'"', """ }, + { L'&', "&" }, + { L'<', "<" }, + { L'>', ">" }, + { L'', " " }, +}; + +static wchar_t entity(const char *name) { + for (size_t i = 0; i < sizeof(Entities) / sizeof(Entities[0]); ++i) { + struct Entity entity = Entities[i]; + if (strncmp(name, entity.name, strlen(entity.name))) continue; + return entity.ch; + } + if (!strncmp(name, "&#x", 3)) return strtoul(&name[3], NULL, 16); + if (!strncmp(name, "&#", 2)) return strtoul(&name[2], NULL, 10); + return 0; +} + +static const char EntityPattern[] = { + "[[:space:]]+|&([[:alpha:]]+|#([[:digit:]]+|x[[:xdigit:]]+));" +}; +static regex_t EntityRegex; + +static void showTitle(const char *title) { + regmatch_t match = {0}; + for (; *title; title += match.rm_eo) { + if (regexec(&EntityRegex, title, 1, &match, 0)) break; + if (title[match.rm_so] != '&') { + printf("%.*s ", (int)match.rm_so, title); + continue; + } + wchar_t ch = entity(&title[match.rm_so]); + if (ch) { + printf("%.*s%lc", (int)match.rm_so, title, (wint_t)ch); + } else { + printf("%.*s", (int)match.rm_eo, title); + } + } + printf("%s\n", title); +} + +static CURL *curl; +static bool title; +static struct { + char buf[64 * 1024]; + size_t len; +} body; + +// HE COMES +static const char TitlePattern[] = "<title>([^<]*)</title>"; +static regex_t TitleRegex; + +static size_t handleBody(char *buf, size_t size, size_t nitems, void *user) { + (void)user; + size_t len = size * nitems; + size_t cap = sizeof(body.buf) - body.len - 1; + size_t new = (len < cap ? len : cap); + if (title || !new) return len; + + memcpy(&body.buf[body.len], buf, new); + body.len += new; + body.buf[body.len] = '\0'; + + regmatch_t match[2]; + if (regexec(&TitleRegex, body.buf, 2, match, 0)) return len; + body.buf[match[1].rm_eo] = '\0'; + showTitle(&body.buf[match[1].rm_so]); + title = true; + + return len; +} + +static CURLcode fetchTitle(const char *url) { + CURLcode code = curl_easy_setopt(curl, CURLOPT_URL, url); + if (code) return code; + + curl_easy_setopt(curl, CURLOPT_NOBODY, 1L); + code = curl_easy_perform(curl); + if (code) return code; + + char *type; + code = curl_easy_getinfo(curl, CURLINFO_CONTENT_TYPE, &type); + if (code) return code; + if (!type || strncmp(type, "text/html", 9)) return CURLE_OK; + + char *dest; + curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &dest); + dest = strdup(dest); + if (!dest) err(EX_OSERR, "strdup"); + + code = curl_easy_setopt(curl, CURLOPT_URL, dest); + if (code) return code; + free(dest); + + body.len = 0; + title = false; + curl_easy_setopt(curl, CURLOPT_HTTPGET, 1L); + code = curl_easy_perform(curl); + return code; +} + +int main(int argc, char *argv[]) { + EntityRegex = regex(EntityPattern, 0); + TitleRegex = regex(TitlePattern, REG_ICASE); + + setlocale(LC_CTYPE, ""); + setlinebuf(stdout); + + CURLcode code = curl_global_init(CURL_GLOBAL_ALL); + if (code) errx(EX_OSERR, "curl_global_init: %s", curl_easy_strerror(code)); + + curl = curl_easy_init(); + if (!curl) errx(EX_SOFTWARE, "curl_easy_init"); + + static char error[CURL_ERROR_SIZE]; + curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, error); + + curl_easy_setopt(curl, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS); + curl_easy_setopt( + curl, CURLOPT_USERAGENT, + "curl/7.54.0 facebookexternalhit/1.1 Twitterbot/1.0" + ); + curl_easy_setopt(curl, CURLOPT_ACCEPT_ENCODING, ""); + curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); + curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 3L); + curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1L); + + curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, handleBody); + + bool exclude = false; + regex_t excludeRegex; + + int opt; + while (0 < (opt = getopt(argc, argv, "x:v"))) { + switch (opt) { + break; case 'x': { + exclude = true; + excludeRegex = regex(optarg, REG_NOSUB); + } + break; case 'v': curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); + break; default: return EX_USAGE; + } + } + + if (optind < argc) { + code = fetchTitle(argv[optind]); + if (!code) return EX_OK; + errx(EX_DATAERR, "curl_easy_perform: %s", error); + } + + char *buf = NULL; + size_t cap = 0; + + regex_t urlRegex = regex("https?://([^[:space:]>\"()]|[(][^)]*[)])+", 0); + while (0 < getline(&buf, &cap, stdin)) { + regmatch_t match = {0}; + for (char *ptr = buf; *ptr; ptr += match.rm_eo) { + if (regexec(&urlRegex, ptr, 1, &match, 0)) break; + ptr[match.rm_eo] = '\0'; + const char *url = &ptr[match.rm_so]; + if (!exclude || regexec(&excludeRegex, url, 0, NULL, 0)) { + code = fetchTitle(url); + if (code) warnx("curl_easy_perform: %s", error); + } + ptr[match.rm_eo] = ' '; + } + } + if (ferror(stdin)) err(EX_IOERR, "getline"); +} |