NAME
    tcping - simulate "ping" over tcp by establishing a connection to network hosts.
    Measures the time for your system to [SYN], receive the target's [SYN][ACK] and send [ACK].  Note that the travel time for
    the last ACK is not included - only the time it takes to be put on the wire a tthe sending end.
SYNOPSIS
    tcping [-tdsvf46] [-i interval] [-n times] [-w interval] [-b n] [-r times][-j depth] [--tee filename] [-f] destination [port]
DESCRIPTION
    tcping measures the time it takes to perform a TCP 3-way handshake (SYN, SYN/ACK, ACK) between itself and a remote host.
    The travel time of the outgoing final ACK is not included, only the (minimal) amount of time it has taken to drop it on
    the wire at the near end.  This allows the travel time of the (SYN, SYN/ACK) to approximate the travel time of the
    ICMP (request, response) equivalent.
    
OPTIONS
    -4      Prefer using IPv4
    -6      Prefer using IPv6
    -t      ping continuously until stopped via control-c
    -n count
            send _count_ pings and then stop.  Default 4.
    
    -i interval
            Wait _interval_ seconds between pings.  Default 1.  Decimals permitted.
    
    -w interval
            Wait _interval_ seconds for a response.  Default 2.  Decimals permitted.
    -d      include date and time on every output line
    
    -f      Force sending at least one byte in addition to making the connection.
    -g count
            Give up after _count_ failed pings.
    
    -b type
            Enable audible beeps.
            '-b 1' will beep "on down".  If a host was up, but now its not, beep.
            '-b 2' will beep "on up".  If a host was down, but now its up, beep.
            '-b 3' will beep "on change".  If a host was one way, but now its the other, beep.
            '-b 4' will beep "always".
    -c      only show output on a changed state
    
    -r count
            Every _count_ pings, we will perform a new DNS lookup for the host in case it changed.
    -s      Exit immediately upon a success.        
    -v      Print version and exit.
    -j      Calculate jitter.  Jitter is defined as the difference between the last response time and the historical average.
    -js depth
            Calculate jitter, as with -j but with an optional _depth_ argument specified. If _depth_ is specified tcping will
            use the prior _depth_ values to calculate a rolling average.
    --tee _filename_
            Duplicate output to the _filename_ specified.  Windows can still not be depended upon to have a useful command line 
            environment. Don't tease me, *nix guys.
    --append
            When using --tee, append to rather than overwrite the output file.
            
    --file
            Treat the "destination" option as a filename.  That file becomes a source of destinations, looped through on a
            line by line basis.  Some options don't work in this mode and statistics will not be kept.
    destination
            A DNS name, an IP address, or (in "http" mode) a URL.
            Do not specify the protocol ("http://") in "http" mode.  Also do not specify server port via ":port" syntax.
            For instance:   "tcping http://www.elifulkerson.com:8080/index.html" would fail
            Use the style:  "tcping www.elifulkerson.com/index.html 8080" instead.
                                
    port
            A numeric TCP port, 1-65535.  If not specified, defaults to 80.
    --header
            include a header with the command line arguments and timestamp.  Header is implied if using --tee.
            
HTTP MODE OPTIONS   
    -h      Use "http" mode.  In http mode we will attempt to GET the specified document and return additional values including
            the document's size, http response code, kbit/s.
    -u      In "http" mode, include the target URL on each output line.
    
    --post  Use POST instead of GET in http mode.
    --head  Use HEAD instead of GET in http mode.
    --get   Shorthand to invoke "http" mode for consistency's sake.
    --proxy-server _proxyserver_
            Connect to _proxyserver_ to request the url rather than the server indicated in the url itself.
    --proxy-port _port_
            Specify the numeric TCP port of the proxy server.  Defaults to 3128.
    --proxy-credentials username:password
            Specify a username:password pair which is sent as a 'Proxy-Authorization: Basic' header.
RETURN VALUE
    tcping returns 0 if all pings are successful, 1 if zero pings are successful and 2 for mixed outcome.
BUGS/REQUESTS
    Please report bugs and feature requests to the author via contact information on http://www.elifulkerson.com
    
AVAILABILITY
    tcping is available at http://www.elifulkerson.com/projects/tcping.php

描述
在本地主机和远程主机之间，tcping可以测试出执行TCP三次握手所需的时间（SYN，SYN / ACK，ACK）。最终ACK传送时间不包括在内，只有最少的时间才能将其丢弃在近端的电线。 

概要
# tcping [-tdsvf46] [-i interval] [-n times] [-w interval] [-b n] [-r times][-j depth] [--tee filename] [-f] destination [port]

选项
-4，优先使用IPv4

-6，优先使用IPv6

-h，使用http模式

-t，让命令持续运行，直到使用ctrl + c指令退出

-n 数字，发送命令的次数，默认4次

-i 数字，发送ping命令的时间间隔，默认1s，可以为小数

-w 数字，等待响应的时间间隔，默认2s，可以为小数

-d，使输出的每一行显示时间和日期

-f，强制ping命令至少发送一个比特（byte）

-g 数字，失败指定次就放弃（注意默认是80端口，若其他端口没开也算失败）

-b 数字，开启蜂鸣器，参数4会一直响铃

-c，只显示改变的信息（ping时间很短一般不会改变）

-r 数字，每发送指定个数据包，就重新查找主机一次（通过DNS或路由查找）

-s，ping通就立即退出

-u，与-h命令连用，每一行输出目标的url

-v，显示版本信息

-j，使用默认的方法，求ping的均值减小波动，网络有一定的不稳定性时，用此参数可以减小波动

-js 数字，用指定个实例求平均值减小波动，使用这个参数，系统会tcping 指定次，然后求出平均值作为一次结果显示，减小波动

–tee file_path，将结果输出到指定位置，tcping –tee /data/test.txt192.168.0.100，会把ping的结果保存在/data下的test文件中

–file，从文件中获得ping的来源；在/data下新建一个test.txt文件，并输入要tcping的所有ip或域名，一行一个，然后执行命令tcping –file /data/test.txt，就会依次tcping文件中指定的地址

destination，可以是DNS地址、IP地址、URL（需要使用-h，http模式）。使用http模式时，不要加https//或:port，例如：tcping http://www.elifulkerson.com:8080/index.html就会失败，使用tcping www.elifulkerson.com/index.html 8080就会成功

port 数字，指定tcp端口（1-65535），如果不指定，默认是80

–header，在头部显示时间和日期，与–tee显示的格式差不多

–block，tcping不通的等待时间，默认是20秒（很长）。–block可以把-w参数冲突掉 ，例如tcping --block www.baiu.com网址不正确，显然tcpping不通，默认会等待20s 。 tcping -w 0.5 –block www.baiu.com还是会等20s，而不是0.5s，因为–block选项会把-w选项冲突掉。

HTTP模式选项
–post，在http模式中，使用post方法

–head，在http模式中，使用head方法

–get Shorthand to invoke “http” mode for consistency’s sake.

–proxy-server，指定代理服务

–proxy-port，指定代理服务端口

–proxy-credentials username:password，使用代理的安全验证，需要输入用户名和密码

返回值
如果所有的pings是成功的，返回0；如果所有ping都失败，返回1；混合结果，返回2

测试：tcping 200.209.200.15 21