linux - 在 unix/linux 命令行中定义函数(例如 BASH)

Question

有时，我会为一项特定任务重复多次单行，但可能永远不会以完全相同的形式再次使用。它包括我从目录列表中粘贴的文件名。介于两者之间并创建一个 bash 脚本，我想也许我可以在命令行中创建一个单行函数，例如:

numresults(){ ls "$1"/RealignerTargetCreator | wc -l }

我已经尝试了一些方法，例如使用 eval、使用 numresults=function...，但还没有找到正确的语法，到目前为止还没有在网上找到任何东西. (接下来的一切都只是关于 bash 函数的教程)。

Answer 1

引用 my answer对于 Ask Ubuntu 上的类似问题:

Functions in bash are essentially named compound commands (or code blocks). From man bash:

Compound Commands
   A compound command is one of the following:
   ...
   { list; }
          list  is simply executed in the current shell environment.  list
          must be terminated with a newline or semicolon.  This  is  known
          as  a  group  command. 

...
Shell Function Definitions
   A shell function is an object that is called like a simple command  and
   executes  a  compound  command with a new set of positional parameters.
   ... [C]ommand is usually a list of commands between { and },  but
   may  be  any command listed under Compound Commands above.

There's no reason given, it's just the syntax.

尝试在 wc -l 后加一个分号:

numresults(){ ls "$1"/RealignerTargetCreator | wc -l; }