Method getOsNetProbeCmd

src/remote/src/tcpportscanner.ts:255–290

()

    protected static OSNetProbeCmd = '';
    protected static OSNetProbeCmdRegexpStr = '';
    protected static getOsNetProbeCmd(): string {
        /**
         * Notes:
         * `netstat` does not exist on Linux by default. Replacement is `ss`
         * `netstat` and `ss` are faster than lsof. netstat on mac is super fast.
         * what program to use is baed of platform and availability
         */
        if (TcpPortScanner.OSNetProbeCmd === '') {
            const commandExistsSync = command_exists.sync;
            const platform = os.platform();
            const isWin = platform === 'win32';
            const isMac = platform === 'darwin';
            /**
             * for `netstat` and `ss` We are looking for things that are in the 'local address' field for
             * ports that are listening. Technically, you can have multiple matches because the local machine
             * can have multiple addresses
             */
            if (!isWin && !isMac && commandExistsSync('ss')) {
                TcpPortScanner.OSNetProbeCmd = 'ss -nlt';
                TcpPortScanner.OSNetProbeCmdRegexpStr = 'LISTEN\\s+[^\\n]*:XYZZY\\s+[^\\s]+[^\\n]*\\n';
            } else if (commandExistsSync('netstat')) {
                // On windows, if you ask for tcp it will only give you ipv4. On Mac, it gives both, so we have to
                // use the -f on Mac
                TcpPortScanner.OSNetProbeCmd = isWin ? 'netstat -nap tcp' : 'netstat -nap tcp -f inet';
                // netstat output varies wildly, so be careful
                TcpPortScanner.OSNetProbeCmdRegexpStr = '[tT][cC][pP][^\\n]*[:\\.]XYZZY\\s+[^\\s]+\\s+LISTEN[^\\n]*\\n';
            } else if (isMac && commandExistsSync('lsof')) {
                // This is the slowest of all but probably the most consistent
                TcpPortScanner.OSNetProbeCmd = 'lsof -n -iTCP:XYZZY -sTCP:LISTEN';
                TcpPortScanner.OSNetProbeCmdRegexpStr = 'IPv4[^\\n]+:XYZZY\\s[^\\n]*\\(LISTEN\\)[^\\n]*\\n';
            } else {
                TcpPortScanner.OSNetProbeCmd = '?';
            }
        }
        return TcpPortScanner.OSNetProbeCmd;
    }

    /**
     * This is the most unobtrusive way of figuring out if a port is open. It does not try