tcsh别名，条件为if-then-else [英] tcsh alias with if-then-else condition

问题描述

我正在尝试在命令结果中使用if-then-else条件
的别名。

I am trying to have an alias with if-then-else condition on a command result.

1. 别名会得到一个文件模式


2. 如果只有一个文件，它将打开文件


3. 如果有多个或少于1个文件，它将打开

我尝试过的别名是：

alias atest 'if \("ls \!:1" > 0 \)  "nedit ls \!:1" else "echo cant open the file" '

推荐答案

有两种方法，大多数都不是优雅，但以下是我发现的最美观，最容易创建的东西：

There are a couple of ways, most of them are not very elegant, but the following is the best looking and easiest to create that I have discovered:

alias aliasname '`if (condition == check) echo "echo"` >&/dev/null && code_if_true || code_if_false'

您可以嵌套if语句遵循这种格式，也可以将其用作如果将if语句的内部更改为

You have the ability to nest if statements following this format, and can also use it as a checker for arguments if you change the interior of the if statement to be

if ("\!:1" =~ "check")

>& / dev / null用于清除函数的输出，但不是必须的。如果您有兴趣，也可以在别名中使用for语句，但是这种方法不太优雅。我没有使用过它，但是如果您希望创建一个具有不同数量参数的别名，则有必要使用它。再说一次，那很丑，所以到那时我只写一个函数。

The >&/dev/null is to clean up the output of the function, but is not necessary. If you are interested, there is also a way to make for statements within aliases, but that method is a lot less elegant. I haven't used it but it is necessary if you wish to create an alias with a varying number of arguments. Again, that one is ugly, so at that point I'd just write a function.

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