问题缘起-报错

$ ./megacc

(megacc:12728): Gtk-WARNING **: cannot open display:

1. google后发现是因为需要在MacOS本地装XQuartz才能在远程显示（display）图形界面程序
2. 有一些误导的帖子说需要在Linux下的.bashrc添加环境变量export DISPLAY=IPv4:0.0

• MacOS本地IPv4地址

  
  
  image.png

3. 尝试后总是Can't open display: 172.16.165.95:0

正确的解决方案

1. 安装最新版的XQuartz
   地址：https://www.xquartz.org
2. 重启电脑 非常重要
3. 在任何一个终端界面输入xterm，如果弹出新窗口就证明成功安装并且调用
4. 直接登录Linux ssh -Y username@host
   注意是-Y
5. 输入xterm测试，可以单出新窗口就证明成功了
   切记，并不需要export DISPLAY=，多此一举就会导致调用不了

参考：
1.https://princetonuniversity.github.io/PUbootcamp/ssh-instructions/

2. https://stackoverflow.com/questions/34919821/gtk-warning-cannot-open-display
3. https://www.cnblogs.com/andrewwang/p/8535081.html

按提示在MacOS本地安装XQuartz

image.png

新分割线 2020-10-13

**参考 **
Instead of using -Y you should use -X
You will need to add the following to .ssh/config on the Mac side:

Host *
    XAuthLocation /opt/X11/bin/xauth

this is because xauth lives in a different location on macos than it normally would on linux

我MacOS的原生配置vi /etc/ssh/ssh_config

#       $OpenBSD: ssh_config,v 1.34 2019/02/04 02:39:42 dtucker Exp $

# This is the ssh client system-wide configuration file.  See
# ssh_config(5) for more information.  This file provides defaults for
# users, and the values can be changed in per-user configuration files
# or on the command line.

# Configuration data is parsed as follows:
#  1. command line options
#  2. user-specific file
#  3. system-wide file
# Any configuration value is only changed the first time it is set.
# Thus, host-specific definitions should be at the beginning of the
# configuration file, and defaults at the end.

# Site-wide defaults for some commonly used options.  For a comprehensive
# list of available options, their meanings and defaults, please see the
# ssh_config(5) man page.

# Host *
#   ForwardAgent no
#   ForwardX11 no
#   PasswordAuthentication yes
#   HostbasedAuthentication no
#   GSSAPIAuthentication no
#   GSSAPIDelegateCredentials no
#   BatchMode no
#   CheckHostIP yes
#   AddressFamily any
#   ConnectTimeout 0
#   StrictHostKeyChecking ask
#   IdentityFile ~/.ssh/id_rsa
#   IdentityFile ~/.ssh/id_dsa
#   IdentityFile ~/.ssh/id_ecdsa
#   IdentityFile ~/.ssh/id_ed25519
#   Port 22
#   Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc
#   MACs hmac-md5,hmac-sha1,umac-64@openssh.com
#   EscapeChar ~
#   Tunnel no
#   TunnelDevice any:any
#   PermitLocalCommand no
#   VisualHostKey no
#   ProxyCommand ssh -q -W %h:%p gateway.example.com
#   RekeyLimit 1G 1h

Host *
        SendEnv LANG LC_*

MacOS用root权限sudo vi /etc/ssh/ssh_config才能编辑，更改后如下

##Host *
##      SendEnv LANG LC_*
Host *
        XAuthLocation /opt/X11/bin/xauth