注:linux中有一个经典名言【一切皆文件】,/dev/null可以认为是一个特殊的空文件,更形象点,可以理解为科幻片中的黑洞,任何信息重向定输出到它后,便有去无回,当然黑洞里也没有信息能出来。 综合来讲,上面的意思就是利用<将黑洞做为demo.txt的标准输入,黑洞里没任何内容,任何文件里的内容被它吞噬了,自然也没就...
7. Bash Trap Command #!/bin/bash# bash trap commandtrap bashtrap INT# bash clear screen commandclear;# bash trap function is executed when CTRL-C is pressed:# bash prints message => Executing bash trap subrutine !bashtrap(){ echo "CTRL+C Detected !...executing bash trap !"}# for l...
Passing several arguments to a function that are stored as a string may not work properly when you have space... Bash - (Argument|Positional Parameter) An argument is a parameter given: to a command to a function or to the bash shell They are referenced by position. A positional ...
Inside a shell script, where the function definition must be before any calls on the function. Alongside other bash alias commands and directly in the terminal as a command. To use bash functions, follow the outlines below. Bash Function Syntax There are two different ways to declare a bash ...
这一行表明,不管用户选择的是那种交互式shell,该脚本需要使用bash shell来运行。由于每种shell的语法大不相同,所以这句非常重要。 简单实例 下面是一个非常简单的shell脚本。它只是运行了几条简单的命令 1 2 3 4 #!/bin/bash echo"hello, $USER. I wish to list some files of yours" ...
my_function 当调用函数时,read命令会等待用户输入,并将输入的值赋给变量name。然后,脚本会继续执行后续的命令。 使用read命令运行函数的优势是可以与用户进行交互,获取用户的输入,并根据输入的值执行相应的逻辑。这在编写交互式脚本或需要用户输入的脚本时非常有用。 read命令的应用场景包括但不限于: 编写交互式脚本...
Reuse functions: Reuse functions wherever possible to avoid rewriting the same code over again. Avoid function name clashes: Avoid using functions with the same name as the built-in commands and other command-line tools.
Inside the function: Declare local variables 'base' and 'exponent' to store the arguments passed to the function. Calculate the result of raising 'base' to the power of 'exponent' using the ** operator. Finally, "echo" command is used to print a message showing the result. ...
Alongside other bash alias commands and directly in the terminal as a command. To use bash functions, follow the outlines below. Bash Function Syntax There are two different ways to declare a bash function: 1. The most widely used format is: ...
The unset bash builtin command is used to unset (delete or remove) any values and attributes from a shell variable or function. This means that you can simply use it to delete a Bash array in full or only remove part of it by specifying the key. unset take the variable name as an ...