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来自：https://www.zhihu.com/question/20019419
The -u tells Git to remember the parameters, so that next time we can simply run git push and Git will know what to do.相当于第一次串门的时候你登了个记办了个vip。。以后再来就知道是你来了。不用脱裤子搜身了

链接：https://www.zhihu.com/question/20019419/answer/80590142

http://m.blog.csdn.net/shen_gan/article/details/8167715

由于git的index文件出错。

需要删除.git/index文件，

然后运行git reset，重新生成index文件。
git reset还可以删除已经commit，但未push上去的信息。

From:https://my.oschina.net/dyxp/blog/380642

FreeBSD11.1好像不是这样的，清空/root/.bash_history没有用：在 /root/.history里，不是.bash_history。
  1000  1:10    mysql -S /tmp/mysql.sock
  1002  1:26    vi /root/.bash_history

history命令的記錄如何刪除？

1、修改/etc/profile將HISTSIZE=1000改成0或1

清除用戶home路徑下.bash_history

2、立即清空裏的history當前曆史命令的記錄

history -c

3、bash執行命令時不是馬上把命令名稱寫入history文件的，而是存放在內部的buffer中，等bash退出時會一並寫入。

不過，可以調用'history -w'命令要求bash立即更新history文件。

history -w

Linux/FreeBSD 终端/ssh登录前后的欢迎信息修改，均无问题，实践Ok，操作如下：
cat /etc/motd
Welcome to jackxiang's Compute Service !


From:http://xoyabc.blog.51cto.com/7401264/1679402

解决办法：
vi ~/.vimrc
let &titleold="jackxiang_owncloud_tools_diff_nginx_php_mysql_redis_47_94_8*_23*"                                                                               set title


FreeBSD下实践OK：
let &titleold=expand("%:p:h") set title

最后修改为：
let &titleold = $USER . "@" . hostname() . ":" .expand("%:p:h")                                                                                               set title
SecureCRT显示：
root@jackxiang_owncloud_tools_diff_nginx_php_mysql_redis_47_94_8*_23*:/root

连接字串来自：https://git.codingallnight.com/chris/dotfiles/commit/46921501e65ab5c731b82280d0497680ff31418e
=================================================
'titleold' 選項。替換固定的字符串 "Thanks for flying Vim"，用來在退出時設置標題。
let &titleold=getcwd()
From:http://vim.wikia.com/wiki/Show_a_useful_title_on_exit_in_an_xterm

My current ~/.vimrc contains (in part)
set title
set titleold=""
set titlestring=VIM:\ %F

From:https://github.com/lazywei/vim-doc-tw/blob/master/doc/version5.twx

More:http://vim.wikia.com/wiki/Show_a_useful_title_on_exit_in_an_xterm

cd /usr/ports/devel/strace/ && make install clean
A package is not available for ports marked as: Forbidden / Broken / Ignore / Restricted
PKGNAME: strace
ONLY_FOR_ARCHS: i386 #不支持AMD.
distinfo:
SHA256 (strace-4.5.18.tar.bz2) = 95e7b7470e04f22c3ec8dc6d0b1fdd8944306cb5313c84c4545cd83abada26d0
SIZE (strace-4.5.18.tar.bz2) = 480973

Install strace

First update FreeBSD ports collection and install strace from /usr/ports/devel/strace:
# portsnap fetch update
# cd /usr/ports/devel/strace
# make install clean

From:https://www.cyberciti.biz/faq/howto-installl-strace-under-freebsd/

人脸识别项目的开源测试程序及代码： https://github.com/Insightzen/autocrop ，要Python2.7以上，得选CentOS7，6的版本低，得编译，还需要python2-pip,得找一个源，epll默认没有，得找一个扩展源，如下：
CentOS7的默认Python版本：Python 2.7.5 ，而autocrop需要装：python2-pip ，
得找一个源，CentOS7下面用Fedora的源，放到，/etc/yum.repos.d，如下：

第一个问题，FreeBSD 10 之後的版本改用unbound 代替了bind
所以已經沒有 nslookup , dig 等指令
可以改用host , drill 等指令
但如果還是習慣 nslookup的話
可以安裝bind-tools 套件

#cd /usr/ports/dns/bind-tools
#make install

安裝完後看看是否真的出現
# which nslookup
/usr/local/bin/nslookup

From:http://blog.sina.com.tw/helloworld/article.php?entryid=651089

cd /usr/ports/devel/git/ && make install clean
nc FreeBSD自带，而netcat需要自己安装，如下：
cd /usr/ports/net/netcat/ && make install clean

第二个问题，关于CentOS如何只知道命令不知道哪个包，而通过YUM的provides命令反查nslookup所在的软件包的？

32:bind-utils-9.9.4-51.el7.x86_64 : Utilities for querying DNS name servers
源    ：updates
匹配来源：
文件名    ：/usr/bin/nslookup

yum provides *bin/nslookup

32:bind-utils-9.9.4-38.el7_3.3.x86_64 : Utilities for querying DNS name servers
源    ：@updates
匹配来源：
文件名    ：/usr/bin/nslookup

================================================

nslookup這個指令對於網路除錯來說，應該是很多人都很習慣的工具
如果發現安裝好的Linux系統少了這個指令

[root@example ~]# nslookup myip.pass.tw
-bash: nslookup: command not found

[root@example ~]# which nslookup
/usr/bin/which: no nslookup in (/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)

直接安裝看看咧? 找不到這個套件名稱
[root@example ~]# yum -y install nslookup
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirrors.linode.com
* epel: mirror.sfo12.us.leaseweb.net
* extras: mirrors.linode.com
* updates: mirrors.linode.com
No package nslookup available.
Error: Nothing to do

試試 yum provides 看看nslookup 是包含在哪個套件中
[root@example ~]# yum provides nslookup
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.linode.com
* epel: mirror.sfo12.us.leaseweb.net
* extras: mirrors.linode.com
* updates: mirrors.linode.com
Warning: 3.0.x versions of yum would erroneously match against filenames.
You can use "*/nslookup" and/or "*bin/nslookup" to get that behaviour
No Matches found

依提示再搜尋一下，可以發現包含在bind-utils 套件中
[root@example ~]# yum provides */nslookup
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.linode.com
* epel: mirror.sfo12.us.leaseweb.net
* extras: mirrors.linode.com
* updates: mirrors.linode.com
base/filelists_db                                                                                                                                                                                                     | 6.4 MB     00:00
epel/filelists_db                                                                                                                                                                                                     | 7.7 MB     00:01
extras/filelists_db                                                                                                                                                                                                   |  25 kB     00:00
updates/filelists_db                                                                                                                                                                                                  | 1.5 MB     00:00
zsh-4.3.11-4.el6.centos.2.x86_64 : A powerful interactive shell
Repo        : base
Matched from:
Filename    : /usr/share/zsh/4.3.11/functions/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6.x86_64 : Utilities for querying DNS name servers
Repo        : base
Matched from:
Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6_9.2.x86_64 : Utilities for querying DNS name servers
Repo        : updates
Matched from:
Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64 : Utilities for querying DNS name servers
Repo        : updates
Matched from:
Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6_9.1.x86_64 : Utilities for querying DNS name servers
Repo        : updates
Matched from:
Filename    : /usr/bin/nslookup

[root@example ~]# yum provides *bin/nslookup
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.linode.com
* epel: mirrors.kernel.org
* extras: mirrors.linode.com
* updates: mirrors.linode.com
32:bind-utils-9.8.2-0.62.rc1.el6.x86_64 : Utilities for querying DNS name servers
Repo        : base
Matched from:
Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6_9.2.x86_64 : Utilities for querying DNS name servers
Repo        : updates
Matched from:
Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64 : Utilities for querying DNS name servers
Repo        : updates
Matched from:
Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.62.rc1.el6_9.1.x86_64 : Utilities for querying DNS name servers
Repo        : updates
Matched from:
Filename    : /usr/bin/nslookup

安裝 bind-utils
[root@example ~]# yum -y install bind-utils
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirrors.linode.com
* epel: mirrors.kernel.org
* extras: mirrors.linode.com
* updates: mirrors.linode.com
Resolving Dependencies
--> Running transaction check
---> Package bind-utils.x86_64 32:9.8.2-0.62.rc1.el6_9.4 will be installed
--> Processing Dependency: bind-libs = 32:9.8.2-0.62.rc1.el6_9.4 for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Processing Dependency: liblwres.so.80()(64bit) for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Processing Dependency: libisccfg.so.82()(64bit) for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Processing Dependency: libisccc.so.80()(64bit) for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Processing Dependency: libisc.so.83()(64bit) for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Processing Dependency: libdns.so.81()(64bit) for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Processing Dependency: libbind9.so.80()(64bit) for package: 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64
--> Running transaction check
---> Package bind-libs.x86_64 32:9.8.2-0.62.rc1.el6_9.4 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================================================================================================================================================================================
Package                                                Arch                                               Version                                                                 Repository                                           Size
=============================================================================================================================================================================================================================================
Installing:
bind-utils                                             x86_64                                             32:9.8.2-0.62.rc1.el6_9.4                                               updates                                             189 k
Installing for dependencies:
bind-libs                                              x86_64                                             32:9.8.2-0.62.rc1.el6_9.4                                               updates                                             892 k

Transaction Summary
=============================================================================================================================================================================================================================================
Install       2 Package(s)

Total download size: 1.1 M
Installed size: 2.7 M
Downloading Packages:
(1/2): bind-libs-9.8.2-0.62.rc1.el6_9.4.x86_64.rpm                                                                                                                                                                    | 892 kB     00:00
(2/2): bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64.rpm                                                                                                                                                                   | 189 kB     00:00
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total                                                                                                                                                                                                         44 MB/s | 1.1 MB     00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : 32:bind-libs-9.8.2-0.62.rc1.el6_9.4.x86_64                                                                                                                                                                                1/2
  Installing : 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64                                                                                                                                                                               2/2
  Verifying  : 32:bind-libs-9.8.2-0.62.rc1.el6_9.4.x86_64                                                                                                                                                                                1/2
  Verifying  : 32:bind-utils-9.8.2-0.62.rc1.el6_9.4.x86_64                                                                                                                                                                               2/2

Installed:
  bind-utils.x86_64 32:9.8.2-0.62.rc1.el6_9.4

Dependency Installed:
  bind-libs.x86_64 32:9.8.2-0.62.rc1.el6_9.4

Complete!

来自：http://blog.sina.com.tw/helloworld/article.php?pbgid=170996&entryid=657249

背景：有的SSH连接提示 host key，很麻烦，如何取消。
The host you specified (47.94.88.*), port 22 matched several entries in the host key database, but the server's host key did not match any of the entries.  See the help file for instructions on manually maintaining the host key database. It is recommended you verify your host key before accepting. Server's host key fingerprint SHA-2 hash: a2:6e:d2:05:de:51:74:49:fe:6a:26:b6:59:d5:2d:0e:39:fa:c5:69:88:eb:97:7c:b5:cd:34:72:de:7f:45:cc SHA-1 hash: 6f:32:91:9d:ad:a4:ea:16:9f:f0:72:b1:90:79:ab:57:48:fe:0c:8f MD5 hash: 22:6c:30:34:80:01:cd:fd:1d:7a:9b:5e:96:b9:17:bc
两步：
一）删除先前的指纹文件：
来自文件：D:\Program Files\SecureCRT\ssh_tmp\SSH2.ini
文件里配置：S:"Host Key Database Location"=D:\Program Files\SecureCRT\ssh_tmp\KnownHosts\
上面的SSH2.ini有可能升级有多个，都统一找一下里面的路径并删除掉有newhostkey问题的IP.pub，都统一批量改成二）里面的配置项。
bash-shell下操作如下：
/d/Program Files/SecureCRT7.3/ssh_tmp/KnownHosts
删除掉：rm -rf '47.94.88.237[47.94.88.237]22.pub

二）配置文件修改，如下：
From:
D:"Automatically Accept Host Keys"=00000000
To:
D:"Automatically Accept Host Keys"=00000001

Save the change, restart SecureCRT.
D:\Program Files\SecureCRT\ssh_tmp\SSH2.ini

内容如下：
S:"Host Key Database Location"=D:\Program Files\SecureCRT\ssh_tmp\KnownHosts\
S:"Host Key Database Location V2"=${VDS_CONFIG_PATH}\KnownHosts\
D:"Automatically Accept Host Keys"=00000001

整个配置如下：
D:\Program Files\SecureCRT\ssh_tmp\SSH2.ini
S:"Host Key Database Location"=D:\Program Files\SecureCRT\ssh_tmp\KnownHosts\ S:"Identity Filename"= S:"SSH1 Identity Filename"= D:"Show Port Forwarding Error Box"=00000001 D:"Public Key Type"=00000000 D:"Enable Agent Forwarding"=00000000 D:"Add Private Keys To Agent"=00000001 D:"Try All Agent Keys"=00000001 D:"Enable Deprecated Gssapi"=00000001 D:"Suppress FQDN Warning"=00000000 D:"Check Certificate Revocation Lists"=00000000 D:"Cache Session Password"=00000000 S:"Monitor Hostkey Filename"= S:"Identity Filename V2"= S:"SSH1 Identity Filename V2"= S:"Host Key Database Location V2"=${VDS_CONFIG_PATH}\KnownHosts\ S:"Monitor Hostkey Filename V2"= D:"Public Key Certificate Store"=00000000 S:"PKCS11 Provider Dll"= S:"Public Key Certificate Serial Number"= S:"Public Key Certificate Issuer"= D:"Use Certificate As Raw Key"=00000001 D:"Automatically Accept Host Keys"=00000001

来自：http://blog.csdn.net/warcraftzhaochen/article/details/73867385

在CentOS下面打Rpm包时用 make install DESTDIR=%{buildroot} ，而在FreeBSD下用make PREFIX=/usr/local/redis install 好像也成：

cd /usr/ports/databases/redis
make PREFIX=/usr/local/redis install

/usr/local/redis/bin/redis-server
/usr/local/redis/bin/redis-cli
/usr/local/redis/bin/redis-check-rdb
/usr/local/redis/bin/redis-benchmark
/usr/local/redis/bin/redis-sentinel

From:https://www.iyunv.com/thread-51148-1-1.html


最新版本5.0：
/usr/local/bin/gmake PREFIX=/usr/local/redis/ install clean

The MySQL server is running with the --read-only option so it cannot execute
解决办法：
mysql> set global read_only=0;
（关掉新主库的只读属性）
flush privileges;
set global read_only=1;(读写属相)
flush privileges;
出现：
The MySQL server is running with the --read-only option so it cannot execute

来自：http://www.cnblogs.com/xionghui/archive/2013/03/01/2939342.html

进程启动时指定CPU
命令taskset -c 1 ./redis-server ../redis.conf

taskset
taskset是LINUX提供的一个命令(ubuntu系统可能需要自行安装，schedutils package)。他可以让某个程序运行在某个（或）某些CPU上。


指定进程运行在某个特定的CPU上

命令taskset -pc 3 21184

显示结果：

pid 21184's current affinity list: 0-23
pid 21184's new affinity list: 3

注：3表示CPU将只会运行在第4个CPU上（从0开始计数）。


来自：http://blog.csdn.net/xluren/article/details/43202201
http://www.361way.com/linux-context-switch/5131.html

用途:用于查看当前服务器读写磁盘情况.
iostat -x 1


5  8781  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5   879  0.0 [kauditd]
  5  8950  0.0 CROND
  5  8951  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5  9116  0.0 CROND
  5  9117  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5  9286  0.0 CROND
  5  9287  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5   930  0.0 CROND
  5   931  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5    94  0.0 [md_misc/5]
  5  9489  0.0 CROND
  5  9490  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5  9659  0.0 CROND
  5  9660  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -
  5  9829  0.0 CROND
  5  9830  0.0 /usr/lib64/sa/sadc -F -L -S DISK 1 1 -

首先需要安装一个包
# rpm -qa sysstat
sysstat-7.0.2-3.el5
这个包安装了一些很有用的文件
# rpm -ql sysstat
/usr/lib/sa/sadc
rpm -qa|grep sysstat
rpm -ql sysstat|grep sadc
/usr/lib64/sa/sadc

=====================================================
要启动SAR，必须通过cron工具以周期性的间隔启动。
安装sysstat包后，默认创建一个/etc/cron.d/sysstat文件，其默认内容为：
# run system activity accounting tool every 10 minutes
*/10 * * * * root /usr/lib/sa/sa1 1 1
# generate a daily summary of process accounting at 23:53
53 23 * * * root /usr/lib/sa/sa2 -A
这里用到了两个命令
/usr/lib/sa/sa1
/usr/lib/sa/sa2
sa1：是调用sadc（二进制文件），将数据收集到二进制日志文件的一个Shell脚本。sa1命令还确保每天使用不同的文件。每隔十分钟运行一次该命令，最好不要改这个值，这是对一般系统折中的值。二进制日志文件存放在/var/log/sa/目录下，命名为sa${DATE}。
sa2：是将当日二进制日志文件中所有的数据转储到文本文件（sar）的另一个Shell脚本，然后它将清除七天之前的所有日志文件。参数-A指定了从二进制文件中提取哪些数据转储到文本文件中。转储的文件存放在/var/log/sa/目录下，命名为sar${DATE}。
这两个命令要配合着使用。
（强烈建议看一下这两个命令的脚本）


查看一下/usr/lib/sa/sa1脚本，里面执行这样一句命令：
/usr/lib/sa/sadc -F -L 1 1 -
-F：强制指定一个储存文件，如果文件已存在，就将其转换成sa的二进制文件形式。
-L：给sa文件加互斥锁，不能让两个sadc进程同时写一个sa文件。


跟据sa1脚本中的命令，我们也可以手动的创建sa二进制文件，使用/usr/lib/sa/sadc命令，
# /usr/lib/sa/sadc 1 10 /tmp/jaylin_sa
上述命令的作用是：每隔1s写一条记录，写10条，存放到二进制文件/tmp/jaylin_sa中。


查看一下/usr/lib/sa/sa2脚本，里面执行这样一句命令：
/usr/bin/sar -A -f /var/log/sa/sa${DATE} > /var/log/sa/sar${DATE}
-A：列出所有存储在/var/log/sa/sa${DATE}里的统计信息。
-f：指定将要转储的sa文件，默认的参数值为/var/log/sa/sa${DATE}。

From:
http://linuxguest.blog.51cto.com/195664/541178/

[实践OK]FreeBSD中安装pkg:https://jackxiang.com/post/10436/
pkg install lrzsz   #一直提示[y|N],没有成功，后用port安装成功了
cd /usr/ports/comms/lrzsz
make install clean
备注：这种方式为编译安装，安装时同样需要联网下载。

/usr/local/bin/lrx
/usr/local/bin/lrz
/usr/local/bin/lsb
/usr/local/bin/lrb
/usr/local/bin/lsx
/usr/local/bin/lsz


Cause

This problem may be caused by improper handling of escape sequences embedded in the files being uploaded.

Resolution

Use the -e or --escape option on lrz, which escapes control characters (Z). For example, type, lrz -e. Some Zmodem clients expect escaping, while others do not.
Notes

Note, some installations of lrzsz do not have the "sz" or "rz" commands, only "lsz" and "lrz". You can edit your .login file and add lines like "alias sz lsz" and "alias rz lrz -e". This way, when you type "sz" or "rz", it will automatically execute the right program with the right options.

lrzsz is part of the FreeBSD ports collection. It contains a set of shell commands for sending and receiving files via the X/Y/ZMODEM protocols. Your SSH or Telnet client must support them for transfers to work.

阅读全文

背景：Git分不同角色在提交时，root提交时是administrator（Crontab用来Pull一些Ansible脚本到本地）, 而xiangdong提交时是xiangdong，往往容易出现一个问题是不小心给root了，这块一是xiangdong上去有时权限不够可能切换为root了，另一个是登录时可能就是Root用户，一提交就成Admin了。鉴于此，自己整个C代码实现提交判断，这样接管了git push，从而对粗心的我来讲起到一个助理的作用。

一、搞这玩意儿的原因：
root情况：
git config -l user.name=Administrator user.email=admin@example.com
xiangdong:
git config -l user.name=xiangdong user.email=xiangdong@justwinit.cn core.autocrlf=input
解决一个无论是root还是xiangdong的环境下，只需要执行下面我们搞的这个c语言生成的二进制文件就能一直只以向东的用户进行提交git，看起来扯淡，但还是有点用的，敲啥呢： gitpush ，和git push只是没有那个空格了。经实践证明是可行的，如下：


二、生产这个玩意的过程：
源码及Makefile和生成的二进制文件路径：
#tree -L 2 ../../gitpush/ ../../gitpush/ ├── bin │   └── gitpush └── src     ├── gitpush.c     └── Makefile

Makefile文件内容：
cat Makefile
gitpush:gitpush.c         gcc -g -o  gitpush -Wall gitpush.c         mv gitpush ../bin         chmod a+x ../bin/gitpush         cp -rf /usr/local/gitpush/src/gitpush.sh /etc/profile.d/gitpush.sh clean:         rm -rf gitpush             rm -rf /etc/profile.d/gitpush.sh
源代码：cat gitpush.c
#include <stdio.h>                                                                         #include <string.h> #include <stdlib.h> #include <sys/types.h> #include <unistd.h> #include <stdarg.h> #include <sys/types.h> #include <pwd.h> int main() {         char curpath[80];         char forbidname[]="root";         char whoami[80];         char command[36000];         FILE *pPipe;         char psBuffer[36000];         struct passwd *pwd;         pwd = getpwuid(getuid());         //printf("当前登陆的用户名为：%s\n", pwd->pw_name);         strcpy(whoami,pwd->pw_name);         getcwd(curpath, sizeof(curpath));         //printf("current working directory : %s\n", curpath);         //printf("The UID is %d \n", getuid());         //strcpy(whoami,getlogin()); #要是先xiangdong登录，再sudo su -成root，值还是向东。         //printf("The login name is %s\n", getlogin());         //printf("The forbidlogin name is %s\n", forbidname);         if(0 == strcmp(forbidname,whoami)){//root，得提示一下换角色再Push                 printf("提醒：请小心，现在正在Root环境下面，立即切换到xiangdong用户并作提交。\n");                 snprintf(command,sizeof(command),"/usr/bin/sudo -i -u xiangdong -H cd %s && git push",curpath);         }else{             snprintf(command,sizeof(command),"cd %s && git push",curpath);         }         printf("执行:%s\n",command);         if( (pPipe = popen( command, "r" )) == NULL ){//执行脚本             printf("Excute Command Faild :%s",command);             exit( 1 );         }         while(!feof(pPipe))/* Read pipe until end of file. */         {             if(fgets(psBuffer, sizeof(psBuffer), pPipe) != NULL)             printf("%s",psBuffer);         }         pclose(pPipe);         return 1; }


最后，PATH路径：
cat /etc/profile.d/gitpush.sh
export PATH=$PATH:/usr/local/gitpush/bin

三、验证步骤阶段：
root下执行情况：
#gitpush
#gitpush
当前登陆的用户名为：root
current working directory : /home/xiangdong/shell
The UID is 0
The login name is xiangdong
The forbidlogin name is root
请小心，你现在正在Root环境下面，不过没关系，我给你切换到xiangdong用户并作提交。执行git push命令：/usr/bin/sudo -i -u xiangdong -H cd /home/xiangdong/shell && git push
Counting objects: 4, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 288 bytes, done.
Total 3 (delta 1), reused 1 (delta 0)
To git@gitlab.qr.justwinit.net:levooops/shell.git
   bd83c51..b400811  master -> master

xiangdong下面执行情况：
$gitpush
执行:cd /home/xiangdong/shell && git push
Counting objects: 5, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 277 bytes, done.
Total 3 (delta 1), reused 0 (delta 0)
To git@gitlab.qr.justwinit.net:levooops/shell.git
   b400811..0b19550  master -> master

成功Log:
$git log
commit 0b195507efa6278774d4f500a7086003d6744684
Author: xiangdong <xiangdong@justwinit.cn>
Date:   Sun Oct 1 23:15:32 2017 +0800

    加上README.md

commit b40081190bf020d49375a4117a181f00ea0a2503
Author: xiangdong <xiangdong@justwinit.cn>
Date:   Sun Oct 1 23:09:58 2017 +0800

    加上README.md

================================================================================
附录：
为什么 sudo cd 会报错 command not found:
https://www.starduster.me/2015/09/12/why-command-not-found-when-sudo-cd/

相关函数：get_current_dir_name, getwd, chdir
头文件：#include <unistd.h>
定义函数：char * getcwd(char * buf, size_t size);
函数说明：getcwd()会将当前的工作目录绝对路径复制到参数buf 所指的内存空间，参数size 为buf 的空间大小。
注：
1、在调用此函数时，buf 所指的内存空间要足够大。若工作目录绝对路径的字符串长度超过参数size 大小，则返回NULL，errno 的值则为ERANGE。
2、倘若参数buf 为NULL，getcwd()会依参数size 的大小自动配置内存(使用malloc())，如果参数size 也为0，则getcwd()会依工作目录绝对路径的字符串程度来决定所配置的内存大小，进程可以在使用完次字符串后利用free()来释放此空间。

返回值：执行成功则将结果复制到参数buf 所指的内存空间, 或是返回自动配置的字符串指针. 失败返回NULL,错误代码存于errno.

范例
#include <unistd.h> main() {     char buf[80];     getcwd(buf, sizeof(buf));     printf("current working directory : %s\n", buf); }

执行：
current working directory :/tmp

cat test_processname.cpp
#include <limits.h> #include <stdio.h> #include <string.h> #include <unistd.h> size_t get_executable_path( char* processdir,char* processname, size_t len) {         char* path_end;         if(readlink("/proc/self/exe", processdir,len) <=0)                 return -1;         path_end = strrchr(processdir,  '/');         if(path_end == NULL)                 return -1;         ++path_end;         strcpy(processname, path_end);         *path_end = '\0';         return (size_t)(path_end - processdir); } int main() {         char path[PATH_MAX];         char processname[1024];         get_executable_path(path, processname, sizeof(path));         printf("directory:%s\nprocessname:%s\n",path,processname);         char buf[80];         getcwd(buf, sizeof(buf));         printf("current working directory : %s\n", buf);         printf("The UID is %d \n", getuid());         printf("The login name is %s\n", getlogin()); }


g++ test_processname.cpp -o gitpush
mv /tmp/gp /usr/local/gitpush/gitpush

cat /etc/profile.d/gp.sh
export PATH=$PATH:/usr/local/gitpush

#gp
directory:/usr/local/gitpush/
processname:gp
current working directory : /root


./gitpush
directory:/tmp/
processname:gitpush
current working directory : /tmp
The UID is 0
The login name is xiangdong

我的问题：git pull
error: Untracked working tree file 'playbook/ml.qr.justwinit.cn/process.yml' would be overwritten by merge.  Aborting
git fetch --all && git reset --hard origin/master
一、解决办法：
$git fetch --all && git reset --hard origin/master Fetching origin HEAD is now at d33031a edit dns playbook

二、再git pull就没有问题了，当然，你的改动也被回退了，得先备份再做这个操作：
$git pull
Already up-to-date.

三、重新将文件放进去，再进行commit后push，没毛病：
git commit -m"xxx" ishow.justwinit.cn.conf.j2
git push
Counting objects: 11, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (6/6), done.
Writing objects: 100% (6/6), 815 bytes, done.
Total 6 (delta 3), reused 0 (delta 0)
To git@gitlab.qr.cntv.net:irdcops/ansible.git
   d33031a..eb4ad86  master -> master
来自：https://www.codecaptain.io/reference/git/the-following-untracked-working-tree-files-would-be-overwritten-by-merge