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Diffstat (limited to '')
| -rw-r--r-- | bin/title.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/bin/title.c b/bin/title.c new file mode 100644 index 00000000..ed9eeccc --- /dev/null +++ b/bin/title.c @@ -0,0 +1,138 @@ +/* Copyright (C) 2019 June 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 <regex.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <strings.h> +#include <sysexits.h> + +static regex_t regex(const char *pattern) { + regex_t regex; + int error = regcomp(®ex, pattern, REG_EXTENDED); + if (!error) return regex; + char buf[256]; + regerror(error, ®ex, buf, sizeof(buf)); + errx(EX_SOFTWARE, "regcomp: %s: %s", buf, pattern); +} + +static CURL *curl; +static bool html; +static struct { + char buf[8192]; + size_t len; +} body; + +static size_t handleHeader(char *buf, size_t size, size_t nitems, void *user) { + (void)user; + size_t len = size * nitems; + const char ContentType[] = "Content-Type: text/html"; + if (sizeof(ContentType) - 1 < len) len = sizeof(ContentType) - 1; + if (!strncasecmp(buf, ContentType, len)) html = true; + return size * nitems; +} + +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; + size_t cpy = (len < cap ? len : cap); + memcpy(&body.buf[body.len], buf, cpy); + body.len += cpy; + return len; +} + +static const char *TitlePattern = "<title>([^<]*)</title>"; +static regex_t TitleRegex; + +static bool getTitle(const char *url) { + CURLcode code = curl_easy_setopt(curl, CURLOPT_URL, url); + if (code) { + warnx("CURLOPT_URL: %s", curl_easy_strerror(code)); + return false; + } + + html = false; + curl_easy_setopt(curl, CURLOPT_NOBODY, 1L); + if ((code = curl_easy_perform(curl))) { + warnx("curl_easy_perform: %s", curl_easy_strerror(code)); + return false; + } + if (!html) return false; + + body.len = 0; + curl_easy_setopt(curl, CURLOPT_NOBODY, 0L); + if ((code = curl_easy_perform(curl))) { + warnx("curl_easy_perform: %s", curl_easy_strerror(code)); + return false; + } + body.buf[body.len - 1] = '\0'; + + regmatch_t match[2]; + int error = regexec(&TitleRegex, body.buf, 2, match, 0); + if (error == REG_NOMATCH) return false; + if (error) errx(EX_SOFTWARE, "regexec: %d", error); + + body.buf[match[1].rm_eo] = '\0'; + char *title = &body.buf[match[1].rm_so]; + + printf("%s\n", title); + return true; +} + +int main(int argc, char *argv[]) { + TitleRegex = regex(TitlePattern); + + 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"); + + curl_easy_setopt(curl, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS); + curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); + curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 5L); + + curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, handleHeader); + curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, handleBody); + + setlinebuf(stdout); + + if (argc > 1) { + return (getTitle(argv[1]) ? EX_OK : EX_DATAERR); + } + + regex_t urlRegex = regex("https?://[^[:space:]>\"]+"); + + char *buf = NULL; + size_t cap = 0; + while (0 < getline(&buf, &cap, stdin)) { + regmatch_t match = {0}; + for (char *url = buf; *url; url += match.rm_eo) { + int error = regexec(&urlRegex, url, 1, &match, 0); + if (error == REG_NOMATCH) break; + if (error) errx(EX_SOFTWARE, "regexec: %d", error); + + url[match.rm_eo] = '\0'; + getTitle(&url[match.rm_so]); + url[match.rm_eo] = ' '; + } + } +} |