unset name||echo $?bash:unset:name:cannot unset:readonly variable1 本文参与腾讯云自媒体同步曝光计划,分享自作者个人站点/博客。 原始发表:2023-01-26,如有侵权请联系cloudcommunity@tencent.com删除 编程算法 shell 【linux命令讲解大全】055.readonly命令:标记Shell变量或函数为只读 ...
Unset Linux is a command used in the Linux operating system to unset or remove an environment variable. Environment variables are settings or values that are used by programs running in the Linux environment to determine their behavior. By unsetting a variable, users can remove its value or exis...
Using+rather than-causes these flags to be turned off. These flags can also be used upon invocation of the shell itself. The current set of flags may be found in the variable$-. The remaining arguments are positional parameters and are assigned, in order, to$1,$2, ... If no arguments...
它实现为一个壳层内建指令，因为它直接操纵shell的内部。只读shell变量不能被unset。如果试图unset只读变量，unset命令将打印一个错误消息，并返回一个非零的退出代码。This command removes one or more variables. Each name is a variable name, specified in any of the ways acceptable to the set ...
unsetlinux UnsetLinuxis a command used in theLinuxoperating system tounsetor remove an environment variable. Environment variables are settings or values that are used by programs running in theLinuxenvi sed ide lua 原创 it入门小白白 2024-03-05 13:55:32 ...
unsetenv variableksh88set [±abCefhkmnopstuvx] [±o option]... [±A name] [arg]...unset [-f] name... **export [name [= value]]...**export [-p]ksh+set [±abCefGhkmnoprstuvx] [±o option]... [±A vname] [arg]......
unsetenv 将删除环境中的 variable。与使用 unset 时一样,不会执行模式匹配。ksh88内置set 的标志具有以下含义:–A数组赋值。取消设置变量 name,并按顺序从 arg 列表中分配值。如果使用了 +A,则不会首先取消设置变量 name。–a自动导出已定义的所有后续变量。–b...
linux命令行精选网 18-05-20 06:23 来自commandlinefu.cn : ${VAR:?unset variable} 检查变量是否存在 O网页链接 û收藏 转发 评论 ñ赞 评论 o p 同时转发到我的微博 按热度 按时间 正在加载,请稍候...linux命令行精选...
This command removes one or more variables. Each name is a variable name, specified in any of the ways acceptable to the set command. If a name refers to an element of an array then that element is removed without affecting the rest of the array. If a ...
unset -f now 再次调用时,now 已找不定定义。...declare -r name="foo" $echo $name foo 使用 unset 删除只读变量将报错并返回失败(1)。 unset name || echo $?...bash: unset: name: cannot unset: readonly variable 1 --- 74330 PHP