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=$(ls \ -1)echo"${MUL...
variable_name=$(command \argument 1 \argument 2 \argument 3) 下面的 bash 指令碼演示了將多行命令的輸出分配給變數。ls命令列出當前資料夾的所有內容,並將輸出通過管道傳送到head命令。head命令僅從ls中選擇輸入的前5行並將輸出通過管道傳輸到grep命令。grep命令匹配帶有單詞flow的行並將其列印到標準輸出。
$ 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...
Single command output to a variable Bash commands can be used without any option and argument for those commands where these parts are optional. The following two examples show the uses of simple command substitution. Example#1: bash `date`command is used to show the current date and time. Th...
While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites. It makes canonical use of exit codes, so you can just add ashellcheckcommand as part of the process. For example, in a Makefile: ...
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 ...
In bash scripts, assigning the output of a command to variables can be convenient by storing the outputs of the commands and using them later. In this short guide, we will take a look at how you can store the output of a command as a variable in Bash. The Basics To Set Up Variables...
You can assign data to a variable using the equals sign (=). The data you store in a variable can either be a string or a number. Let’s create a variable now on the command line: chapter_number=5 The variable name is on the left hand side of the equals sign, and the data whic...
In this script,%oinprintf “%o”specifies the format to treat the input variabledecimalNumberas an octal number, effectively converting it from decimal to octal. It’s time to execute the script: # bashdecimal_to_octal.sh This command runs the script, prompting you to enter a decimal number...