第一种语法,是设置一个变量为只读变量并且可以选择是否赋值,如果此时不赋值,那么设置为只读后就无法再赋值或者改值了。 -a:指明name为索引数组(indexed array)。 -A:指明name为关联数组(associative array)。 -f:指明name为函数(function)。 [root@c7-server ~]# readonly age=28[root@c7-server ~]# age=3...
Bash支持两种数组,一种是所谓索引数组(indexed array),通过下标0,1,2...(跟大多数编程语言一样,下标从零开始,想起了孙燕姿的歌《爱从零开始》~)访问其中的元素,第二种叫做关联数组(associative array),通过Key来访问Value,也就是所谓的键值对(或Map)。我们首先看一下数组的声明和定义(Bash手册中查找关键字Arra...
Bash 使用可以通过命令设置的属性来允许类似类型的行为,因为 bash 类型系统不健壮。 declare是一个内置的 Bash 命令,允许你在 shell 范围内更改变量的特征。 它还可以对变量进行速写声明。最后,它使你可以访问变量。 declare -A创建一个associative array变量,一个键值对数组,其值由关键字索引。 除了影响其行为的变...
exportPATH="$HOME/.cabal/bin:$PATH" Log out and in again, and verify that your PATH is set up correctly: $whichshellcheck ~/.cabal/bin/shellcheck On native Windows, thePATHshould already be set up, but the system may use a legacy codepage. Incmd.exe,powershell.exeand Powershell ISE...
Supported attributes of variables: String, this is the default and not displayed Indexed array, e.g. bydeclare -a Associative array, e.g. bydeclare -A Read–only, e.g. byreadonly Exported, e.g. byexport Integer, e.g. bydeclare -i ...
When indexing Bash associative arrays, always use quotes. The static parser will otherwise have to assume that the index is an arithmetic expression. $echo'${array[spaced string]}'|shfmt 1:16: not a valid arithmetic operator: string $echo'${array[dash-string]}'|shfmt${array[dash - string...
Assignment statements may also appear as arguments to the alias, declare, typeset, export, readonly, and local builtin commands. In the context where an assignment statement is assigning a value to a shell variable or array index, the += operator can be used to append to or add to the ...
/usr/bin/env bash cd "$(dirname "$0")" # Go to the script's directory export TEST="This is a test" echo "Your message: {{TEST}}" | ../mo The result? "Your message: This is a test". Using arrays adds a slight level of complexity.You must sourcemo.Look atdemo/using-arrays...
BASH_CMDS Associative array variable whose members correspond to the internal hash table of commands as maintained by the hash builtin. Elements added to this array appear in the hash table; unsetting array elements cause commands to be removed from the hash table. BASH_COMMAND The command curren...
declare –a name :表明数组array declare –f name :表明函数function declare –i name :定义整型变量 declare –r name :表示只读。不能使用unset declare –x name :同export,在当前的环境中起作用,也在外部的shell环境中起作用,本地变量 test命令检查最后所执行命令的状态。test测试一个表达式,然后返回真或...