pg_isready.c

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/*-------------------------------------------------------------------------
 *
 * pg_isready --- checks the status of the PostgreSQL server
 *
 * Copyright (c) 2013, PostgreSQL Global Development Group
 *
 * src/bin/scripts/pg_isready.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres_fe.h"
#include "common.h"

#define DEFAULT_CONNECT_TIMEOUT "3"

static void
help(const char *progname);

int
main(int argc, char **argv)
{
    int c,optindex,opt_index = 2;

    const char *progname;

    const char *pghost = NULL;
    const char *pgport = NULL;
    const char *pguser = NULL;
    const char *pgdbname = NULL;
    const char *connect_timeout = DEFAULT_CONNECT_TIMEOUT;

    const char *keywords[7] = { NULL };
    const char *values[7] = { NULL };

    bool quiet = false;

    PGPing rv;
    PQconninfoOption *connect_options, *conn_opt_ptr;

    /*
     * We accept user and database as options to avoid
     * useless errors from connecting with invalid params
     */

    static struct option long_options[] = {
            {"dbname", required_argument, NULL, 'd'},
            {"host", required_argument, NULL, 'h'},
            {"port", required_argument, NULL, 'p'},
            {"quiet", no_argument, NULL, 'q'},
            {"timeout", required_argument, NULL, 't'},
            {"username", required_argument, NULL, 'U'},
            {NULL, 0, NULL, 0}
        };

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

    while ((c = getopt_long(argc, argv, "d:h:p:qt:U:V", long_options, &optindex)) != -1)
    {
        switch (c)
        {
            case 'd':
                pgdbname = pg_strdup(optarg);
                break;
            case 'h':
                pghost = pg_strdup(optarg);
                break;
            case 'p':
                pgport = pg_strdup(optarg);
                break;
            case 'q':
                quiet = true;
                break;
            case 't':
                connect_timeout = pg_strdup(optarg);
                break;
            case 'U':
                pguser = pg_strdup(optarg);
                break;
            default:
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
                /*
                 * We need to make sure we don't return 1 here because someone
                 * checking the return code might infer unintended meaning
                 */
                exit(PQPING_NO_ATTEMPT);
        }
    }

    if (optind < argc)
    {
        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);
        /*
         * We need to make sure we don't return 1 here because someone
         * checking the return code might infer unintended meaning
         */
        exit(PQPING_NO_ATTEMPT);
    }

    /*
     * Set connection options
     */

    keywords[0] = "connect_timeout";
    values[0] = connect_timeout;
    keywords[1] = "fallback_application_name";
    values[1] = progname;
    if (pguser)
    {
        keywords[opt_index] = "user";
        values[opt_index] = pguser;
        opt_index++;
    }
    if (pgdbname)
    {
        keywords[opt_index] = "dbname";
        values[opt_index] = pgdbname;
        opt_index++;
    }

    /*
     * Get the default host and port so we can display them in our output
     */
    connect_options = PQconndefaults();
    conn_opt_ptr = connect_options;
    while (conn_opt_ptr->keyword)
    {
        if (strncmp(conn_opt_ptr->keyword, "host", 5) == 0)
        {
            if (pghost)
            {
                keywords[opt_index] = conn_opt_ptr->keyword;
                values[opt_index] = pghost;
                opt_index++;
            }
            else if (conn_opt_ptr->val)
                pghost = conn_opt_ptr->val;
            else
                pghost = DEFAULT_PGSOCKET_DIR;
        }
        else if (strncmp(conn_opt_ptr->keyword, "port", 5) == 0)
        {
            if (pgport)
            {
                keywords[opt_index] = conn_opt_ptr->keyword;
                values[opt_index] = pgport;
                opt_index++;
            }
            else if (conn_opt_ptr->val)
                pgport = conn_opt_ptr->val;
        }
        conn_opt_ptr++;
    }

    rv = PQpingParams(keywords, values, 1);

    if (!quiet)
    {
        printf("%s:%s - ", pghost, pgport);

        switch (rv)
        {
            case PQPING_OK:
                printf("accepting connections\n");
                break;
            case PQPING_REJECT:
                printf("rejecting connections\n");
                break;
            case PQPING_NO_RESPONSE:
                printf("no response\n");
                break;
            case PQPING_NO_ATTEMPT:
                printf("no attempt\n");
                break;
            default:
                printf("unknown\n");
        }
    }

    PQconninfoFree(connect_options);

    exit(rv);
}

static void
help(const char *progname)
{
    printf(_("%s issues a connection check to a PostgreSQL database.\n\n"), progname);
    printf(_("Usage:\n"));
    printf(_("  %s [OPTION]...\n"), progname);

    printf(_("\nOptions:\n"));
    printf(_("  -d, --dbname=DBNAME      database name\n"));
    printf(_("  -q, --quiet              run quietly\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(_("  -t, --timeout=SECS       seconds to wait when attempting connection, 0 disables (default: %s)\n"), DEFAULT_CONNECT_TIMEOUT);
    printf(_("  -U, --username=USERNAME  database username\n"));
    printf(_("\nReport bugs to <[email protected]>.\n"));
}