SCRIPTING AND SHELL 脚本和Shell

Shell basics Shell 基础知识

Command editing 命令编辑

• vi
• emacs

Pipes and redirection 管道和重定向

$ echo "This is a test message." > /tmp/mymessage

Variables and quoting 变量和引用

$ ectdir='/etc'
$ echo $etcdir
/etc

Common filter commands 常见的过滤命令

cut

separate lines into fields

sort

sort lines 排序行 Opt | Meaning | Chinese
—|—|—
-b | Ignore leading whitespace | 忽略前导空白
-f | Case insensitive sorting | 不分大小写排序
-k | Specify the columns that form the sort key | 指定组成排序键的列
-n | Compare fields as integer numbers | 将字段作为整数进行比较
-r | Reverse sort order | 反向排序顺序
-t | Set field separator(the default is whitespace) | 设置字段分隔符(默认为空格)
-u | Output unique records only | 只输出独特的记录

uniq

print unique lines

wc

count lines, words, and characters

tee

copy input to two places

grep

search text