但是,当我运行$MOREF变量中包含的命令时,我能够获得输出。 我想知道如何获取需要在脚本中运行的命令的结果,将其保存到变量,然后在屏幕上输出该变量? 除了反引号(`command`)之外,你可以使用$(command),我发现它更容易阅读,并允许嵌套。 OUTPUT="$(ls -1)"echo"${OUTPUT}"MULTILINE=$(ls \ -1)echo"${
output=`command`output=`command argument-1`output=`/path/to/command`output=`/path/to/command argument-1` Bash 命令輸出到變數 我們使用以下示例來演示 bash 指令碼中的命令替換。 下面,我們在開頭使用括號和美元符號的第一種語法。whoami命令被執行,輸出替換命令,然後分配給user變數。我們使用echo命令將訊息顯...
$ unset x $ showvar $x is not set $ x=3 $ showvar $x is not set $ export x $ showvar $x = 3 $ x= ## in bash, reassignment doesn't remove a variable from the environment $ showvar $x is set but empty 注意 showvar不是一个 bash 命令,而是一个如清单 5-1 所示的脚本,...
tion,declareandtypeset makeeachname local,aswiththe local command, unless the -goptionissup‐ plied.Ifa variable nameisfollowedby=value, the valueofthe variableissettovalue.Whenus‐ ing -aor-Aandthe compound assignment syntaxtocreate array variables, additional attributesdonottakeeffectuntilsubsequent...
command, not just those that precede thecommandname.-mJob control is enabled.-nRead commands butdonot execute them.-ooption-name Set the variable corresponding to option-name: allexport same as-abraceexpand same as-Bemacs use an emacs-style line editing interface ...
Output: Using command substitution in loop You can store the output of command substitution into any loop variable which is shown in the next example. Example#5: Create a file namedcmdsub2.shwith the following code. Here, `ls -d */` command is used to retrieve all directory list from ...
# alias ls # command # shellcheck disable=SC1001 \ls绕过shell函数# function ls # command command lscommand命令 调用指定的指令并执行,命令执行时不查询shell函数。command命令只能够执行shell内部的命令。在后台运行命令这将运行给定命令并使其保持后台运行,即使终端或SSH连接中断后也是如此。但是会忽略所有输出...
value of the $location variable is not evaluatedaz group create--name$resourceGroup--location$location# Notice that the space in the $location variable is not ignored and the command fails as it treats the value after the space as a new commandaz group create--name$resourceGroup--location"$...
( )将command group置于sub-shell去执行,也称nested sub-shell,它有一点非常重要的特性是:继承父shell的Standard input, output, and error plus any other open file descriptors。 exec命令:常用来替代当前shell并重新启动一个shell,换句话说,并没有启动子shell。使用这一命令时任何现有环境都将会被清除。exec在对...
# NOTE: This variable may be empty. # Optionally set a fallback to the hostname command. "${HOSTNAME:-$(hostname)}" 获取操作系统的体系结构 "$HOSTTYPE" 获取操作系统/内核的名称 这可用于为不同的操作系统添加条件支持, 而无需调用uname。