droplang.c

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/*-------------------------------------------------------------------------
 *
 * droplang
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/bin/scripts/droplang.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres_fe.h"

#include "common.h"
#include "print.h"

#define atooid(x)  ((Oid) strtoul((x), NULL, 10))


static void help(const char *progname);


int
main(int argc, char *argv[])
{
    static struct option long_options[] = {
        {"list", no_argument, NULL, 'l'},
        {"host", required_argument, NULL, 'h'},
        {"port", required_argument, NULL, 'p'},
        {"username", required_argument, NULL, 'U'},
        {"no-password", no_argument, NULL, 'w'},
        {"password", no_argument, NULL, 'W'},
        {"dbname", required_argument, NULL, 'd'},
        {"echo", no_argument, NULL, 'e'},
        {NULL, 0, NULL, 0}
    };

    const char *progname;
    int         optindex;
    int         c;
    bool        listlangs = false;
    const char *dbname = NULL;
    char       *host = NULL;
    char       *port = NULL;
    char       *username = NULL;
    enum trivalue prompt_password = TRI_DEFAULT;
    bool        echo = false;
    char       *langname = NULL;
    char       *p;
    PQExpBufferData sql;
    PGconn     *conn;
    PGresult   *result;

    progname = get_progname(argv[0]);
    set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pgscripts"));

    handle_help_version_opts(argc, argv, "droplang", help);

    while ((c = getopt_long(argc, argv, "lh:p:U:wWd:e", long_options, &optindex)) != -1)
    {
        switch (c)
        {
            case 'l':
                listlangs = true;
                break;
            case 'h':
                host = pg_strdup(optarg);
                break;
            case 'p':
                port = pg_strdup(optarg);
                break;
            case 'U':
                username = pg_strdup(optarg);
                break;
            case 'w':
                prompt_password = TRI_NO;
                break;
            case 'W':
                prompt_password = TRI_YES;
                break;
            case 'd':
                dbname = pg_strdup(optarg);
                break;
            case 'e':
                echo = true;
                break;
            default:
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
                exit(1);
        }
    }

    /*
     * We set dbname from positional arguments if it is not already set by
     * option arguments -d. If not doing listlangs, positional dbname must
     * follow positional langname.
     */

    if (argc - optind > 0)
    {
        if (listlangs)
        {
            if (dbname == NULL)
                dbname = argv[optind++];
        }
        else
        {
            langname = argv[optind++];
            if (argc - optind > 0 && dbname == NULL)
                dbname = argv[optind++];
        }
    }

    if (argc - optind > 0)
    {
        fprintf(stderr, _("%s: too many command-line arguments (first is \"%s\")\n"),
                progname, argv[optind]);
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
        exit(1);
    }

    if (dbname == NULL)
    {
        if (getenv("PGDATABASE"))
            dbname = getenv("PGDATABASE");
        else if (getenv("PGUSER"))
            dbname = getenv("PGUSER");
        else
            dbname = get_user_name(progname);
    }

    initPQExpBuffer(&sql);

    /*
     * List option
     */
    if (listlangs)
    {
        printQueryOpt popt;
        static const bool translate_columns[] = {false, true};

        conn = connectDatabase(dbname, host, port, username, prompt_password,
                               progname, false);

        printfPQExpBuffer(&sql, "SELECT lanname as \"%s\", "
                "(CASE WHEN lanpltrusted THEN '%s' ELSE '%s' END) as \"%s\" "
                          "FROM pg_catalog.pg_language WHERE lanispl;",
                          gettext_noop("Name"),
                          gettext_noop("yes"), gettext_noop("no"),
                          gettext_noop("Trusted?"));
        result = executeQuery(conn, sql.data, progname, echo);

        memset(&popt, 0, sizeof(popt));
        popt.topt.format = PRINT_ALIGNED;
        popt.topt.border = 1;
        popt.topt.start_table = true;
        popt.topt.stop_table = true;
        popt.topt.encoding = PQclientEncoding(conn);
        popt.title = _("Procedural Languages");
        popt.translate_header = true;
        popt.translate_columns = translate_columns;
        printQuery(result, &popt, stdout, NULL);

        PQfinish(conn);
        exit(0);
    }

    if (langname == NULL)
    {
        fprintf(stderr, _("%s: missing required argument language name\n"),
                progname);
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit(1);
    }

    /* lower case language name */
    for (p = langname; *p; p++)
        if (*p >= 'A' && *p <= 'Z')
            *p += ('a' - 'A');

    conn = connectDatabase(dbname, host, port, username, prompt_password,
                           progname, false);

    /*
     * Force schema search path to be just pg_catalog, so that we don't have
     * to be paranoid about search paths below.
     */
    executeCommand(conn, "SET search_path = pg_catalog;", progname, echo);

    /*
     * Make sure the language is installed
     */
    printfPQExpBuffer(&sql, "SELECT oid "
                      "FROM pg_language WHERE lanname = '%s' AND lanispl;",
                      langname);
    result = executeQuery(conn, sql.data, progname, echo);
    if (PQntuples(result) == 0)
    {
        PQfinish(conn);
        fprintf(stderr, _("%s: language \"%s\" is not installed in "
                          "database \"%s\"\n"),
                progname, langname, dbname);
        exit(1);
    }
    PQclear(result);

    /*
     * Attempt to drop the language.  We do not use CASCADE, so that the drop
     * will fail if there are any functions in the language.
     */
    printfPQExpBuffer(&sql, "DROP EXTENSION \"%s\";\n", langname);

    if (echo)
        printf("%s", sql.data);
    result = PQexec(conn, sql.data);
    if (PQresultStatus(result) != PGRES_COMMAND_OK)
    {
        fprintf(stderr, _("%s: language removal failed: %s"),
                progname, PQerrorMessage(conn));
        PQfinish(conn);
        exit(1);
    }

    PQclear(result);
    PQfinish(conn);
    exit(0);
}


static void
help(const char *progname)
{
    printf(_("%s removes a procedural language from a database.\n\n"), progname);
    printf(_("Usage:\n"));
    printf(_("  %s [OPTION]... LANGNAME [DBNAME]\n"), progname);
    printf(_("\nOptions:\n"));
    printf(_("  -d, --dbname=DBNAME       database from which to remove the language\n"));
    printf(_("  -e, --echo                show the commands being sent to the server\n"));
    printf(_("  -l, --list                show a list of currently installed languages\n"));
    printf(_("  -V, --version             output version information, then exit\n"));
    printf(_("  -?, --help                show this help, then exit\n"));
    printf(_("\nConnection options:\n"));
    printf(_("  -h, --host=HOSTNAME       database server host or socket directory\n"));
    printf(_("  -p, --port=PORT           database server port\n"));
    printf(_("  -U, --username=USERNAME   user name to connect as\n"));
    printf(_("  -w, --no-password         never prompt for password\n"));
    printf(_("  -W, --password            force password prompt\n"));
    printf(_("\nReport bugs to <[email protected]>.\n"));
}