Shell Cookies
1 前言
一些常用的命令，包括使用Emacs的小技巧。
2 ffmpeg
# -r 指定频率 $ ffmpeg -i xxx.mp4 -r 25 xxx.%05d.gif
3 ab
Apache HTTP server benchmarking tool
常用的参数
-n 总请求 -c 并发数 -t 测试所进行的最大秒数 -k 打开KeepAlive功能
结果解释
Server Software: nginx/1.4.6
Server Hostname: 10.69.109.51
Server Port: 80
Document Path: /login.html
Document Length: 1935 bytes
Concurrency Level: 100 # 并发数
Time taken for tests: 0.552 seconds # 测试时间
Complete requests: 1000 # 完成的请求数
Failed requests: 0 # 失败的请求数
Total transferred: 2249000 bytes # 总共传输的数据量
HTML transferred: 1935000 bytes # 请求页面大小
Requests per second: 1810.97 [#/sec] (mean) # 每秒处理的请求数（事务数） 平均值
Time per request: 55.219 [ms] (mean) # 每次并发耗时 平均值
Time per request: 0.552 [ms] (mean, across all concurrent requests) # 每次请求耗时 平均值 注：每次请求耗时 * 并发数 = 每次并发耗时
Transfer rate: 3977.41 [Kbytes/sec] received # 网络中传输速率
Connection Times (ms)
min mean[+/-sd] median max
Connect: 5 25 10.5 23 56
Processing: 10 28 8.9 26 58
Waiting: 10 27 8.8 26 58
Total: 28 53 10.9 51 82
Percentage of the requests served within a certain time (ms)
50% 51
66% 55
75% 58
80% 64
90% 70
95% 73
98% 75
99% 80
100% 82 (longest request)
Reference:
4 grep
grep -rnw '/path/to/somewhere/' -e "pattern"
Reference: http://stackoverflow.com/a/16957078/1925954
5 Emacs
5.1 插入当前时间
C-u M-! date
5.2 Org-mode
5.2.1 Table Sort
C-c ^
6 etags & ctags
cd /path/to/my/project ctags -e -R *.cpp *.hpp *.h cd /path/to/my/project find . | grep ".*\.\(hh\|hxx\|cc\)" | xargs etags -f TAGS cd /path/to/my/project find . -type f -iname "*.[ch]" | etags -
常用热键
`M-.’ (‘find-tag’) – find a tag, that is, use the Tags file to look up a definition. If there are multiple tags in the project with the same name `C-u M-.’ to go to the next match. ‘M-x find-tag-other-window’ – selects the buffer containing the tag’s definition in another window, and move point there. ‘M-*’ (‘pop-tag-mark’) – jump back ‘M-x tags-search’ – regexp-search through the source files indexed by a tags file (a bit like ‘grep’) ‘M-x tags-query-replace’ – query-replace through the source files indexed by a tags file `M-,’ (‘tags-loop-continue’) – resume ‘tags-search’ or ‘tags-query-replace’ starting at point in a source file ‘M-x tags-apropos’ – list all tags in a tags file that match a regexp ‘M-x list-tags’ – list all tags defined in a source file
7 用户篇
7.1 增加用户：
# -s指定shell # -g指定组名 # -G指定加入组（附加组） useradd -s /bin/sh -g group –G adm,root gem
Reference:
7.2 批量增加用户:
#!/bin/bash/ # 创建用户 for i in `cat user.list` do useradd -d /home/$i -m $i useradd -g wsng $i echo "password" | passwd --stdin $i done
someone1 someone2 someone3
Reference:
7.3 增加用户到组:
增加一个新用户到主要用户组：
# 增加用户icecream到wsng # -g将新增加的用户初始化为指定登录组，此名必须存在 useradd -g wsng icecream
增加一个已有用户到一个已有用户组中
# 用户icecream不必离开原组 usermod -a -G wsng icecream # 将用户组改为wsng usermod -g wsng icecream