bti/trunk/bti.c

/*
 * Copyright (C) 2008 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (C) 2009 Bart Trojanowski <bart@jukie.net>
 *
 * 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 version 2 of the License.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <getopt.h>
#include <errno.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <curl/curl.h>
#include <readline/readline.h>
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <pcre.h>


#define zalloc(size)    calloc(size, 1)

#define dbg(format, arg...)                                             \
        do {                                                            \
                if (debug)                                              \
                        fprintf(stdout, "bti: %s: " format , __func__ , \
                                ## arg);                                \
        } while (0)


static int debug;

enum host {
        HOST_TWITTER = 0,
        HOST_IDENTICA = 1,
};

enum action {
        ACTION_UPDATE = 0,
        ACTION_FRIENDS = 1,
        ACTION_USER = 2,
        ACTION_REPLIES = 4,
        ACTION_PUBLIC = 8,
        ACTION_UNKNOWN = 16
};

struct session {
        char *password;
        char *account;
        char *tweet;
        char *proxy;
        char *time;
        char *homedir;
        char *logfile;
        char *user;
        int bash;
        int shrink_urls;
        int dry_run;
        int page;
        enum host host;
        enum action action;
};

struct bti_curl_buffer {
        char *data;
        enum action action;
        int length;
};

static void display_help(void)
{
        fprintf(stdout, "bti - send tweet to twitter or identi.ca\n");
        fprintf(stdout, "Version: " VERSION "\n");
        fprintf(stdout, "Usage:\n");
        fprintf(stdout, "  bti [options]\n");
        fprintf(stdout, "options are:\n");
        fprintf(stdout, "  --account accountname\n");
        fprintf(stdout, "  --password password\n");
        fprintf(stdout, "  --action action\n");
        fprintf(stdout, "    ('update', 'friends', 'public', 'replies' "
                "or 'user')\n");
        fprintf(stdout, "  --user screenname\n");
        fprintf(stdout, "  --proxy PROXY:PORT\n");
        fprintf(stdout, "  --host HOST\n");
        fprintf(stdout, "  --logfile logfile\n");
        fprintf(stdout, "  --shrink-urls\n");
        fprintf(stdout, "  --page PAGENUMBER\n");
        fprintf(stdout, "  --bash\n");
        fprintf(stdout, "  --debug\n");
        fprintf(stdout, "  --dry-run\n");
        fprintf(stdout, "  --version\n");
        fprintf(stdout, "  --help\n");
}

static void display_version(void)
{
        fprintf(stdout, "bti - version %s\n", VERSION);
}

static struct session *session_alloc(void)
{
        struct session *session;

        session = zalloc(sizeof(*session));
        if (!session)
                return NULL;
        return session;
}

static void session_free(struct session *session)
{
        if (!session)
                return;
        free(session->password);
        free(session->account);
        free(session->tweet);
        free(session->proxy);
        free(session->time);
        free(session->homedir);
        free(session->user);
        free(session);
}

static struct bti_curl_buffer *bti_curl_buffer_alloc(enum action action)
{
        struct bti_curl_buffer *buffer;

        buffer = zalloc(sizeof(*buffer));
        if (!buffer)
                return NULL;

        /* start out with a data buffer of 1 byte to
         * make the buffer fill logic simpler */
        buffer->data = zalloc(1);
        if (!buffer->data) {
                free(buffer);
                return NULL;
        }
        buffer->length = 0;
        buffer->action = action;
        return buffer;
}

static void bti_curl_buffer_free(struct bti_curl_buffer *buffer)
{
        if (!buffer)
                return;
        free(buffer->data);
        free(buffer);
}

static const char *twitter_user_url    = "http://twitter.com/statuses/user_timeline/";
static const char *twitter_update_url  = "https://twitter.com/statuses/update.xml";
static const char *twitter_public_url  = "http://twitter.com/statuses/public_timeline.xml";
static const char *twitter_friends_url = "https://twitter.com/statuses/friends_timeline.xml";
static const char *twitter_replies_url = "http://twitter.com/statuses/replies.xml";

static const char *identica_user_url    = "http://identi.ca/api/statuses/user_timeline/";
static const char *identica_update_url  = "http://identi.ca/api/statuses/update.xml";
static const char *identica_public_url  = "http://identi.ca/api/statuses/public_timeline.xml";
static const char *identica_friends_url = "http://identi.ca/api/statuses/friends_timeline.xml";
static const char *identica_replies_url = "http://identi.ca/api/statuses/replies.xml";

static CURL *curl_init(void)
{
        CURL *curl;

        curl = curl_easy_init();
        if (!curl) {
                fprintf(stderr, "Can not init CURL!\n");
                return NULL;
        }
        /* some ssl sanity checks on the connection we are making */
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
        return curl;
}

static void parse_statuses(xmlDocPtr doc, xmlNodePtr current)
{
        xmlChar *text = NULL;
        xmlChar *user = NULL;
        xmlNodePtr userinfo;

        current = current->xmlChildrenNode;
        while (current != NULL) {
                if (current->type == XML_ELEMENT_NODE) {
                        if (!xmlStrcmp(current->name, (const xmlChar *)"text"))
                                text = xmlNodeListGetString(doc, current->xmlChildrenNode, 1);
                        if (!xmlStrcmp(current->name, (const xmlChar *)"user")) {
                                userinfo = current->xmlChildrenNode;
                                while (userinfo != NULL) {
                                        if ((!xmlStrcmp(userinfo->name, (const xmlChar *)"screen_name"))) {
                                                if (user)
                                                        xmlFree(user);
                                                user = xmlNodeListGetString(doc, userinfo->xmlChildrenNode, 1);
                                        }
                                        userinfo = userinfo->next;
                                }
                        }
                        if (user && text) {
                                printf("[%s] %s\n", user, text);
                                xmlFree(user);
                                xmlFree(text);
                                user = NULL;
                                text = NULL;
                        }
                }
                current = current->next;
        }

        return;
}

static void parse_timeline(char *document)
{
        xmlDocPtr doc;
        xmlNodePtr current;

        doc = xmlReadMemory(document, strlen(document), "timeline.xml",
                            NULL, XML_PARSE_NOERROR);
        if (doc == NULL)
                return;

        current = xmlDocGetRootElement(doc);
        if (current == NULL) {
                fprintf(stderr, "empty document\n");
                xmlFreeDoc(doc);
                return;
        }

        if (xmlStrcmp(current->name, (const xmlChar *) "statuses")) {
                fprintf(stderr, "unexpected document type\n");
                xmlFreeDoc(doc);
                return;
        }

        current = current->xmlChildrenNode;
        while (current != NULL) {
                if ((!xmlStrcmp(current->name, (const xmlChar *)"status")))
                        parse_statuses(doc, current);
                current = current->next;
        }
        xmlFreeDoc(doc);

        return;
}

static size_t curl_callback(void *buffer, size_t size, size_t nmemb,
                            void *userp)
{
        struct bti_curl_buffer *curl_buf = userp;
        size_t buffer_size = size * nmemb;
        char *temp;

        if ((!buffer) || (!buffer_size) || (!curl_buf))
                return -EINVAL;

        /* add to the data we already have */
        temp = zalloc(curl_buf->length + buffer_size + 1);
        if (!temp)
                return -ENOMEM;

        memcpy(temp, curl_buf->data, curl_buf->length);
        free(curl_buf->data);
        curl_buf->data = temp;
        memcpy(&curl_buf->data[curl_buf->length], (char *)buffer, buffer_size);
        curl_buf->length += buffer_size;
        if (curl_buf->action)
                parse_timeline(curl_buf->data);

        dbg("%s\n", curl_buf->data);

        return buffer_size;
}

static int send_request(struct session *session)
{
        char user_password[500];
        char data[500];
        /* is there usernames longer than 22 chars? */
        char user_url[70];
        struct bti_curl_buffer *curl_buf;
        CURL *curl = NULL;
        CURLcode res;
        struct curl_httppost *formpost = NULL;
        struct curl_httppost *lastptr = NULL;
        struct curl_slist *slist = NULL;

        if (!session)
                return -EINVAL;

        curl_buf = bti_curl_buffer_alloc(session->action);
        if (!curl_buf)
                return -ENOMEM;

        curl = curl_init();
        if (!curl)
                return -EINVAL;

        switch (session->action) {
        case ACTION_UPDATE:
                snprintf(user_password, sizeof(user_password), "%s:%s",
                         session->account, session->password);
                snprintf(data, sizeof(data), "status=\"%s\"", session->tweet);
                curl_formadd(&formpost, &lastptr,
                             CURLFORM_COPYNAME, "status",
                             CURLFORM_COPYCONTENTS, session->tweet,
                             CURLFORM_END);

                curl_formadd(&formpost, &lastptr,
                             CURLFORM_COPYNAME, "source",
                             CURLFORM_COPYCONTENTS, "bti",
                             CURLFORM_END);

                curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
                slist = curl_slist_append(slist, "Expect:");
                curl_easy_setopt(curl, CURLOPT_HTTPHEADER, slist);
                switch (session->host) {
                case HOST_TWITTER:
                        curl_easy_setopt(curl, CURLOPT_URL,
                                         twitter_update_url);
                        break;
                case HOST_IDENTICA:
                        curl_easy_setopt(curl, CURLOPT_URL,
                                         identica_update_url);
                        break;
                }
                curl_easy_setopt(curl, CURLOPT_USERPWD, user_password);

                break;
        case ACTION_FRIENDS:
                snprintf(user_password, sizeof(user_password), "%s:%s",
                         session->account, session->password);
                switch (session->host) {
                case HOST_TWITTER:
                        sprintf(user_url, "%s?page=%d", twitter_friends_url, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                case HOST_IDENTICA:
                        sprintf(user_url, "%s?page=%d", identica_friends_url, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                }
                curl_easy_setopt(curl, CURLOPT_USERPWD, user_password);

                break;
        case ACTION_USER:
                switch (session->host) {
                case HOST_TWITTER:
                        sprintf(user_url, "%s%s.xml?page=%d", twitter_user_url, session->user, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                case HOST_IDENTICA:
                        sprintf(user_url, "%s%s.xml?page=%d", identica_user_url, session->user, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                }

                break;
        case ACTION_REPLIES:
                snprintf(user_password, sizeof(user_password), "%s:%s",
                         session->account, session->password);
                switch (session->host) {
                case HOST_TWITTER:
                        sprintf(user_url, "%s?page=%d", twitter_replies_url, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                case HOST_IDENTICA:
                        sprintf(user_url, "%s?page=%d", identica_replies_url, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                }
                curl_easy_setopt(curl, CURLOPT_USERPWD, user_password);

                break;
        case ACTION_PUBLIC:
                switch (session->host) {
                case HOST_TWITTER:
                        sprintf(user_url, "%s?page=%d", twitter_public_url, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                case HOST_IDENTICA:
                        sprintf(user_url, "%s?page=%d", identica_public_url, session->page);
                        curl_easy_setopt(curl, CURLOPT_URL, user_url);
                        break;
                }

                break;
        default:
                break;
        }

        if (session->proxy)
                curl_easy_setopt(curl, CURLOPT_PROXY, session->proxy);

        if (debug)
                curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);

        dbg("user_password = %s\n", user_password);
        dbg("data = %s\n", data);
        dbg("proxy = %s\n", session->proxy);

        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_callback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, curl_buf);
        if (!session->dry_run) {
                res = curl_easy_perform(curl);
                if (res && !session->bash) {
                        fprintf(stderr, "error(%d) trying to perform "
                                "operation\n", res);
                        return -EINVAL;
                }
        }

        curl_easy_cleanup(curl);
        if (session->action == ACTION_UPDATE)
                curl_formfree(formpost);
        bti_curl_buffer_free(curl_buf);
        return 0;
}

static void parse_configfile(struct session *session)
{
        FILE *config_file;
        char *line = NULL;
        size_t len = 0;
        char *account = NULL;
        char *password = NULL;
        char *host = NULL;
        char *proxy = NULL;
        char *logfile = NULL;
        char *action = NULL;
        char *user = NULL;
        char *file;
        int shrink_urls = 0;

        /* config file is ~/.bti  */
        file = alloca(strlen(session->homedir) + 7);

        sprintf(file, "%s/.bti", session->homedir);

        config_file = fopen(file, "r");

        /* No error if file does not exist or is unreadable.  */
        if (config_file == NULL)
                return;

        do {
                ssize_t n = getline(&line, &len, config_file);
                if (n < 0)
                        break;
                if (line[n - 1] == '\n')
                        line[n - 1] = '\0';
                /* Parse file.  Format is the usual value pairs:
                   account=name
                   passwort=value
                   # is a comment character
                */
                *strchrnul(line, '#') = '\0';
                char *c = line;
                while (isspace(*c))
                        c++;
                /* Ignore blank lines.  */
                if (c[0] == '\0')
                        continue;

                if (!strncasecmp(c, "account", 7) && (c[7] == '=')) {
                        c += 8;
                        if (c[0] != '\0')
                                account = strdup(c);
                } else if (!strncasecmp(c, "password", 8) &&
                           (c[8] == '=')) {
                        c += 9;
                        if (c[0] != '\0')
                                password = strdup(c);
                } else if (!strncasecmp(c, "host", 4) &&
                           (c[4] == '=')) {
                        c += 5;
                        if (c[0] != '\0')
                                host = strdup(c);
                } else if (!strncasecmp(c, "proxy", 5) &&
                           (c[5] == '=')) {
                        c += 6;
                        if (c[0] != '\0')
                                proxy = strdup(c);
                } else if (!strncasecmp(c, "logfile", 7) &&
                           (c[7] == '=')) {
                        c += 8;
                        if (c[0] != '\0')
                                logfile = strdup(c);
                } else if (!strncasecmp(c, "action", 6) &&
                           (c[6] == '=')) {
                        c += 7;
                        if (c[0] != '\0')
                                action = strdup(c);
                } else if (!strncasecmp(c, "user", 4) &&
                                (c[4] == '=')) {
                        c += 5;
                        if (c[0] != '\0')
                                user = strdup(c);
                } else if (!strncasecmp(c, "shrink-urls", 11) &&
                                (c[11] == '=')) {
                        c += 12;
                        if (!strncasecmp(c, "true", 4) ||
                                        !strncasecmp(c, "yes", 3))
                                shrink_urls = 1;
                }
        } while (!feof(config_file));

        if (password)
                session->password = password;
        if (account)
                session->account = account;
        if (host) {
                if (strcasecmp(host, "twitter") == 0)
                        session->host = HOST_TWITTER;
                if (strcasecmp(host, "identica") == 0)
                        session->host = HOST_IDENTICA;
                free(host);
        }
        if (proxy) {
                if (session->proxy)
                        free(session->proxy);
                session->proxy = proxy;
        }
        if (logfile)
                session->logfile = logfile;
        if (action) {
                if (strcasecmp(action, "update") == 0)
                        session->action = ACTION_UPDATE;
                else if (strcasecmp(action, "friends") == 0)
                        session->action = ACTION_FRIENDS;
                else if (strcasecmp(action, "user") == 0)
                        session->action = ACTION_USER;
                else if (strcasecmp(action, "replies") == 0)
                        session->action = ACTION_REPLIES;
                else if (strcasecmp(action, "public") == 0)
                        session->action = ACTION_PUBLIC;
                else
                        session->action = ACTION_UNKNOWN;
                free(action);
        }
        if (user)
                session->user = user;
        session->shrink_urls = shrink_urls;

        /* Free buffer and close file.  */
        free(line);
        fclose(config_file);
}

static void log_session(struct session *session, int retval)
{
        FILE *log_file;
        char *filename;
        char *host;

        /* Only log something if we have a log file set */
        if (!session->logfile)
                return;

        filename = alloca(strlen(session->homedir) +
                          strlen(session->logfile) + 3);

        sprintf(filename, "%s/%s", session->homedir, session->logfile);

        log_file = fopen(filename, "a+");
        if (log_file == NULL)
                return;
        switch (session->host) {
        case HOST_TWITTER:
                host = "twitter";
                break;
        case HOST_IDENTICA:
                host = "identi.ca";
                break;
        default:
                host = "unknown";
                break;
        }

        switch (session->action) {
        case ACTION_UPDATE:
                if (retval)
                        fprintf(log_file, "%s: host=%s tweet failed\n",
                                session->time, host);
                else
                        fprintf(log_file, "%s: host=%s tweet=%s\n",
                                session->time, host, session->tweet);
                break;
        case ACTION_FRIENDS:
                fprintf(log_file, "%s: host=%s retrieving friends timeline\n",
                        session->time, host);
                break;
        case ACTION_USER:
                fprintf(log_file, "%s: host=%s retrieving %s's timeline\n",
                        session->time, host, session->user);
                break;
        case ACTION_REPLIES:
                fprintf(log_file, "%s: host=%s retrieving replies\n",
                        session->time, host);
                break;
        case ACTION_PUBLIC:
                fprintf(log_file, "%s: host=%s retrieving public timeline\n",
                        session->time, host);
                break;
        default:
                break;
        }

        fclose(log_file);
}

static char *get_string_from_stdin(void)
{
        char *temp;
        char *string;

        string = zalloc(1000);
        if (!string)
                return NULL;

        if (!fgets(string, 999, stdin))
                return NULL;
        temp = strchr(string, '\n');
        *temp = '\0';
        return string;
}

static int find_urls(const char *tweet, int **pranges)
{
        /*
         * magic obtained from
         * http://www.geekpedia.com/KB65_How-to-validate-an-URL-using-RegEx-in-Csharp.html
         */
        static const char *re_magic =
                "(([a-zA-Z][0-9a-zA-Z+\\-\\.]*:)/{1,3}"
                "[0-9a-zA-Z;/~?:@&=+$\\.\\-_'()%]+)"
                "(#[0-9a-zA-Z;/?:@&=+$\\.\\-_!~*'()%]+)?";
        pcre *re;
        const char *errptr;
        int erroffset;
        int ovector[10] = {0,};
        const size_t ovsize = sizeof(ovector)/sizeof(*ovector);
        int startoffset, tweetlen;
        int i, rc;
        int rbound = 10;
        int rcount = 0;
        int *ranges = malloc(sizeof(int) * rbound);

        re = pcre_compile(re_magic,
                        PCRE_NO_AUTO_CAPTURE,
                        &errptr, &erroffset, NULL);
        if (!re) {
                fprintf(stderr, "pcre_compile @%u: %s\n", erroffset, errptr);
                exit(1);
        }

        tweetlen = strlen(tweet);
        for (startoffset = 0; startoffset < tweetlen; ) {

                rc = pcre_exec(re, NULL, tweet, strlen(tweet), startoffset, 0,
                                ovector, ovsize);
                if (rc == PCRE_ERROR_NOMATCH)
                        break;

                if (rc < 0) {
                        fprintf(stderr, "pcre_exec @%u: %s\n",
                                erroffset, errptr);
                        exit(1);
                }

                for (i = 0; i < rc; i += 2) {
                        if ((rcount+2) == rbound) {
                                rbound *= 2;
                                ranges = realloc(ranges, sizeof(int) * rbound);
                        }

                        ranges[rcount++] = ovector[i];
                        ranges[rcount++] = ovector[i+1];
                }

                startoffset = ovector[1];
        }

        pcre_free(re);

        *pranges = ranges;
        return rcount;
}

/**
 * bidirectional popen() call
 *
 * @param rwepipe - int array of size three
 * @param exe - program to run
 * @param argv - argument list
 * @return pid or -1 on error
 *
 * The caller passes in an array of three integers (rwepipe), on successful
 * execution it can then write to element 0 (stdin of exe), and read from
 * element 1 (stdout) and 2 (stderr).
 */
static int popenRWE(int *rwepipe, const char *exe, const char *const argv[])
{
        int in[2];
        int out[2];
        int err[2];
        int pid;
        int rc;

        rc = pipe(in);
        if (rc < 0)
                goto error_in;

        rc = pipe(out);
        if (rc < 0)
                goto error_out;

        rc = pipe(err);
        if (rc < 0)
                goto error_err;

        pid = fork();
        if (pid > 0) {
                /* parent */
                close(in[0]);
                close(out[1]);
                close(err[1]);
                rwepipe[0] = in[1];
                rwepipe[1] = out[0];
                rwepipe[2] = err[0];
                return pid;
        } else if (pid == 0) {
                /* child */
                close(in[1]);
                close(out[0]);
                close(err[0]);
                close(0);
                rc = dup(in[0]);
                close(1);
                rc = dup(out[1]);
                close(2);
                rc = dup(err[1]);

                execvp(exe, (char **)argv);
                exit(1);
        } else
                goto error_fork;

        return pid;

error_fork:
        close(err[0]);
        close(err[1]);
error_err:
        close(out[0]);
        close(out[1]);
error_out:
        close(in[0]);
        close(in[1]);
error_in:
        return -1;
}

static int pcloseRWE(int pid, int *rwepipe)
{
        int rc, status;
        close(rwepipe[0]);
        close(rwepipe[1]);
        close(rwepipe[2]);
        rc = waitpid(pid, &status, 0);
        return status;
}

static char *shrink_one_url(int *rwepipe, char *big)
{
        int biglen = strlen(big);
        char *small;
        int smalllen;
        int rc;

        rc = dprintf(rwepipe[0], "%s\n", big);
        if (rc < 0)
                return big;

        smalllen = biglen + 128;
        small = malloc(smalllen);
        if (!small)
                return big;

        rc = read(rwepipe[1], small, smalllen);
        if (rc < 0 || rc > biglen)
                goto error_free_small;

        if (strncmp(small, "http://", 7))
                goto error_free_small;

        smalllen = rc;
        while (smalllen && isspace(small[smalllen-1]))
                        small[--smalllen] = 0;

        free(big);
        return small;

error_free_small:
        free(small);
        return big;
}

static char *shrink_urls(char *text)
{
        int *ranges;
        int rcount;
        int i;
        int inofs = 0;
        int outofs = 0;
        const char *const shrink_args[] = {
                "bti-shrink-urls",
                NULL
        };
        int shrink_pid;
        int shrink_pipe[3];
        int inlen = strlen(text);

        dbg("before len=%u\n", inlen);

        shrink_pid = popenRWE(shrink_pipe, shrink_args[0], shrink_args);
        if (shrink_pid < 0)
                return text;

        rcount = find_urls(text, &ranges);
        if (!rcount)
                return text;

        for (i = 0; i < rcount; i += 2) {
                int url_start = ranges[i];
                int url_end = ranges[i+1];
                int long_url_len = url_end - url_start;
                char *url = strndup(text + url_start, long_url_len);
                int short_url_len;
                int not_url_len = url_start - inofs;

                dbg("long  url[%u]: %s\n", long_url_len, url);
                url = shrink_one_url(shrink_pipe, url);
                short_url_len = url ? strlen(url) : 0;
                dbg("short url[%u]: %s\n", short_url_len, url);

                if (!url || short_url_len >= long_url_len) {
                        /* The short url ended up being too long
                         * or unavailable */
                        if (inofs) {
                                strncpy(text + outofs, text + inofs,
                                                not_url_len + long_url_len);
                        }
                        inofs += not_url_len + long_url_len;
                        outofs += not_url_len + long_url_len;

                } else {
                        /* copy the unmodified block */
                        strncpy(text + outofs, text + inofs, not_url_len);
                        inofs += not_url_len;
                        outofs += not_url_len;

                        /* copy the new url */
                        strncpy(text + outofs, url, short_url_len);
                        inofs += long_url_len;
                        outofs += short_url_len;
                }

                free(url);
        }

        /* copy the last block after the last match */
        if (inofs) {
                int tail = inlen - inofs;
                if (tail) {
                        strncpy(text + outofs, text + inofs, tail);
                        outofs += tail;
                }
        }

        free(ranges);

        (void)pcloseRWE(shrink_pid, shrink_pipe);

        text[outofs] = 0;
        dbg("after len=%u\n", outofs);
        return text;
}

int main(int argc, char *argv[], char *envp[])
{
        static const struct option options[] = {
                { "debug", 0, NULL, 'd' },
                { "account", 1, NULL, 'a' },
                { "password", 1, NULL, 'p' },
                { "host", 1, NULL, 'H' },
                { "proxy", 1, NULL, 'P' },
                { "action", 1, NULL, 'A' },
                { "user", 1, NULL, 'u' },
                { "logfile", 1, NULL, 'L' },
                { "shrink-urls", 0, NULL, 's' },
                { "help", 0, NULL, 'h' },
                { "bash", 0, NULL, 'b' },
                { "dry-run", 0, NULL, 'n' },
                { "page", 1, NULL, 'g' },
                { "version", 0, NULL, 'v' },
                { }
        };
        struct session *session;
        pid_t child;
        char *tweet;
        int retval = 0;
        int option;
        char *http_proxy;
        time_t t;
        int page_nr;

        debug = 0;
        rl_bind_key('\t', rl_insert);

        session = session_alloc();
        if (!session) {
                fprintf(stderr, "no more memory...\n");
                return -1;
        }

        /* get the current time so that we can log it later */
        time(&t);
        session->time = strdup(ctime(&t));
        session->time[strlen(session->time)-1] = 0x00;

        session->homedir = strdup(getenv("HOME"));

        curl_global_init(CURL_GLOBAL_ALL);

        /* Set environment variables first, before reading command line options
         * or config file values. */
        http_proxy = getenv("http_proxy");
        if (http_proxy) {
                if (session->proxy)
                        free(session->proxy);
                session->proxy = strdup(http_proxy);
                dbg("http_proxy = %s\n", session->proxy);
        }

        parse_configfile(session);

        while (1) {
                option = getopt_long_only(argc, argv, "dqe:p:P:H:a:A:u:hg:sn",
                                          options, NULL);
                if (option == -1)
                        break;
                switch (option) {
                case 'd':
                        debug = 1;
                        break;
                case 'a':
                        if (session->account)
                                free(session->account);
                        session->account = strdup(optarg);
                        dbg("account = %s\n", session->account);
                        break;
                case 'g':
                        page_nr = atoi(optarg);
                        dbg("page = %d\n", page_nr);
                        session->page = page_nr;
                        break;
                case 'p':
                        if (session->password)
                                free(session->password);
                        session->password = strdup(optarg);
                        dbg("password = %s\n", session->password);
                        break;
                case 'P':
                        if (session->proxy)
                                free(session->proxy);
                        session->proxy = strdup(optarg);
                        dbg("proxy = %s\n", session->proxy);
                        break;
                case 'A':
                        if (strcasecmp(optarg, "update") == 0)
                                session->action = ACTION_UPDATE;
                        else if (strcasecmp(optarg, "friends") == 0)
                                session->action = ACTION_FRIENDS;
                        else if (strcasecmp(optarg, "user") == 0)
                                session->action = ACTION_USER;
                        else if (strcasecmp(optarg, "replies") == 0)
                                session->action = ACTION_REPLIES;
                        else if (strcasecmp(optarg, "public") == 0)
                                session->action = ACTION_PUBLIC;
                        else
                                session->action = ACTION_UNKNOWN;
                        dbg("action = %d\n", session->action);
                        break;
                case 'u':
                        if (session->user)
                                free(session->user);
                        session->user = strdup(optarg);
                        dbg("user = %s\n", session->user);
                        break;
                case 'L':
                        if (session->logfile)
                                free(session->logfile);
                        session->logfile = strdup(optarg);
                        dbg("logfile = %s\n", session->logfile);
                        break;
                case 's':
                        session->shrink_urls = 1;
                        break;
                case 'H':
                        if (strcasecmp(optarg, "twitter") == 0)
                                session->host = HOST_TWITTER;
                        if (strcasecmp(optarg, "identica") == 0)
                                session->host = HOST_IDENTICA;
                        dbg("host = %d\n", session->host);
                        break;
                case 'b':
                        session->bash = 1;
                        break;
                case 'h':
                        display_help();
                        goto exit;
                case 'n':
                        session->dry_run = 1;
                        break;
                case 'v':
                        display_version();
                        goto exit;
                default:
                        display_help();
                        goto exit;
                }
        }

        /*
         * Show the version to make it easier to determine what
         * is going on here
         */
        if (debug)
                display_version();

        if (session->action == ACTION_UNKNOWN) {
                fprintf(stderr, "Unknown action, valid actions are:\n");
                fprintf(stderr, "'update', 'friends', 'public', "
                        "'replies' or 'user'.\n");
                goto exit;
        }

        if (!session->account) {
                fprintf(stdout, "Enter twitter account: ");
                session->account = readline(NULL);
        }

        if (!session->password) {
                fprintf(stdout, "Enter twitter password: ");
                session->password = readline(NULL);
        }

        if (session->action == ACTION_UPDATE) {
                if (session->bash)
                        tweet = get_string_from_stdin();
                else
                        tweet = readline("tweet: ");
                if (!tweet || strlen(tweet) == 0) {
                        dbg("no tweet?\n");
                        return -1;
                }

                if (session->shrink_urls)
                        tweet = shrink_urls(tweet);

                session->tweet = zalloc(strlen(tweet) + 10);
                if (session->bash)
                        sprintf(session->tweet, "%c %s", getuid() ? '$' : '#', tweet);
                else
                        sprintf(session->tweet, "%s", tweet);

                free(tweet);
                dbg("tweet = %s\n", session->tweet);
        }

        if (!session->user)
                session->user = strdup(session->account);

        if (session->page == 0)
                session->page = 1;
        dbg("account = %s\n", session->account);
        dbg("password = %s\n", session->password);
        dbg("host = %d\n", session->host);
        dbg("action = %d\n", session->action);

        /* fork ourself so that the main shell can get on
         * with it's life as we try to connect and handle everything
         */
        if (session->bash) {
                child = fork();
                if (child) {
                        dbg("child is %d\n", child);
                        exit(0);
                }
        }

        retval = send_request(session);
        if (retval && !session->bash)
                fprintf(stderr, "operation failed\n");

        log_session(session, retval);
exit:
        session_free(session);
        return retval;;
}