tered, an attemptismadetodefine afunctionusing``-f foo=bar'', an attempt is made to assign avaluetoareadonlyvariable, an attemptismadetoassign a valuetoan array variable withoutusingthe compound assignment syntax (see Arrays above), oneofthe namesisnota valid shell variable name, an attempti...
# 从用户输入中读取变量值 echo "请输入您的名字:" read user_name echo "您好,$user_name!" 如果需要为变量赋值一个空值,可以使用unset命令: 代码语言:txt 复制 # 取消变量的值 unset my_variable 还可以使用环境变量为变量赋值。例如,可以使用$PATH环境变量: 代码语言:txt 复制 # 使用环境变量为变量赋值 ...
(2)特殊用法(遍历文件的每一行):while read line; do控制变量初始化 循环体done < /PATH/FROM/SOMEFILE或cat /PATH/FROM/SOMEFILE | while read line; do 循环体done依次读取/PATH/FROM/SOMEFILE文件中的每一行,且将行赋值给变量line (3)案例: ① 100以内所有正奇数之和 sum=0 i=1 while [ $i -le...
Create a bash file and then add the below-mentioned code in this file to read the file content. You can store the previous text file into a new variable$filenameand variable$nis used to keep the value of each line. Now, using the while loop we will read each line from a file with...
可以使用read命令来实现。read命令用于从标准输入读取用户输入的值,并将其赋给一个变量。 具体用法如下: ``` read variable_name ``` 其中,variable_name是...
#! /bin/bash read word if (( $word = "y" || $word = "Y" )) then echo "YES" elif (( $word = "n" || $word = "N" )) then echo "NO" fi 我得到这个错误: Solution.sh: line 5: ((: y = y || y = Y : attempted assignment to non-variable (error token is "= Y...
首先,Shell 是一个程序,提供一个与用户对话的环境。这个环境只有一个命令提示符,让用户从键盘输入命令,所以又称为命令行环境(commandline,简写为 CLI)。Shell 接收到用户输入的命令,将命令送入操作系统执行,并将结果返回给用户。本书中,除非特别指明,Shell 指的就是命令行环境。
From the below execution, you can notice the error message when you assign invalid data to a variable. $ ./declar.sh 123 t.sh: line 6: 12.3: syntax error: invalid arithmetic operator (error token is ".3") 123 t.sh: line 11: rovar: readonly variable ...
From your terminal Runshellcheck yourscriptin your terminal for instant output, as seen above. In your editor You can see ShellCheck suggestions directly in a variety of editors. Vim, throughALE,Neomake, orSyntastic: . Emacs, throughFlycheckorFlymake: ...
echo 'This is the first line'; echo 'This is the second line' # 声明一个变量: Variable="Some string" # 下面是错误的做法: Variable = "Some string" # Bash 会把 Variable 当做一个指令,由于找不到该指令,因此这里会报错。 # 也不可以这样: ...