标签：取消 script c++ 转义字符 mod 执行 解释 shell 创建
1. 创建可执行文件 t2.sh 并打印 "hello world!"
xiluhua@localhost ~ $ mkdir tscripts xiluhua@localhost ~ $ cd tscripts/ xiluhua@localhost ~/tscripts $ echo ‘#!/bin/bash‘ >> t2.sh xiluhua@localhost ~/tscripts $ echo ‘echo "hello world!"‘ >>t2.sh xiluhua@localhost ~/tscripts $ chmod +x * xiluhua@localhost ~/tscripts $ ./t2.sh hello world!
2. 运行可执行文件的 3中方法
xiluhua@localhost ~/tscripts $ ./t2.sh hello world! xiluhua@localhost ~/tscripts $ sh t2.sh hello world! xiluhua@localhost ~/tscripts $ /bin/sh t2.sh hello world!
3. 使用变量
xiluhua@localhost ~/tscripts $ name=zhangsan xiluhua@localhost ~/tscripts $ echo $name zhangsan xiluhua@localhost ~/tscripts $ echo ${name} zhangsan xiluhua@localhost ~/tscripts $
变量名外面的花括号是可选的，可加可不加，加花括号是为了帮助解释器识别变量的边界
4. for 循环打印 java c c++ php scala，体会 ${} 的作用
#!/bin/bash for skill in java c c++ php scala;do echo "I am good at $skill" done echo "=======================================" for skill in java c c++ php scala;do echo "I am good at $skillScript" done echo "=======================================" for skill in java c c++ php scala;do echo "I am good at ${skill}Script" done
5. 只读变量，unset 不能取消
xiluhua@localhost ~/tscripts $ name=jack xiluhua@localhost ~/tscripts $ readonly name xiluhua@localhost ~/tscripts $ echo $name jack xiluhua@localhost ~/tscripts $ name=Tom -bash: name: readonly variable xiluhua@localhost ~/tscripts $ unset name -bash: unset: name: cannot unset: readonly variable xiluhua@localhost ~/tscripts $
6. 非只读变量可以取消，取消后打印为空
xiluhua@localhost ~/tscripts $ unname=Jerry xiluhua@localhost ~/tscripts $ unset unname xiluhua@localhost ~/tscripts $ echo $unname
7. 单引号
①. 单引号里的任何字符都原样输出，单引号变量中的变量是无效的； ②. 单引号字符串中不能出现单引号，对单引号使用转义符后也不行 xiluhua@localhost ~ $ name=‘Leo‘ xiluhua@localhost ~ $ echo ‘$name‘ $name xiluhua@localhost ~ $ echo ‘$‘name‘ >
8. 双引号
①. 双引号里可以有变量 ②. 双引号里可以出现转义字符 xiluhua@localhost ~ $ echo "I am $name" I am Leo xiluhua@localhost ~ $ echo "\\I am $name \\" \I am Leo \
9. 拼接字符串
xiluhua@localhost ~ $ echo "He is $name" He is Leo xiluhua@localhost ~ $ echo "$name is handsome"! Leo is handsome! xiluhua@localhost ~ $ echo "$name is handsome!" -bash: !": event not found
10. 获取字符串长度
xiluhua@localhost ~ $ echo ${#name} 3
11. 提取字符串
xiluhua@localhost ~ $ echo ${name:0:2}
Le
12.
标签：取消 script c++ 转义字符 mod 执行 解释 shell 创建
原文地址：http://www.cnblogs.com/xiluhua/p/6285061.html
