命令/别名可以变量？ [英] Can a command/alias be variable?

问题描述

我需要不时查看日志文件的特定行时间：

  $头-10的log.txt |尾-1＃查看log.txt中的第10行
 

然后我写了一个函数 v 我的的.bashrc 来使生活更轻松：

  $ V 10
 

好吧，也许我在这里我有点分裂的头发：我想忽略空间太：

  $ V10
 

我知道的唯一方法是定义许多别名：

 别名V1 ='V 1'
别名V2 ='V 2'
别名V3 ='V 3'
别名V4 ='V 4'
...
 

对此有什么好的办法？

---

感谢@Chirlo和@anishsane为理念。

下面是我的最终版本的基础上，@ anishsane与一些修正：

 的eval`声明-f command_not_found_handle | sed的S / command_not_found_handle / command_not_found_handle_orig /`
command_not_found_handle（）{
    如果expr匹配$ 1V [0-9] [0-9] *＆GT;的/ dev / null的;然后
       V $ {1：1}
       返回$？
    科幻
    command_not_found_handle_orig$ @
}
 

解决方案

这是不是一个答案，而是一个提示：

当你给Ubuntu的一些命令，＆安培;如果未安装该程序，然后外壳调用自己的处理程序，并称

 程序'东西'是当前未安装。您可以通过键入安装：
sudo易于得到安装的东西
 

您可以尝试找到那片程序，它这样做了。然后勾你的code，指令是否匹配的正则表达式这看起来 v [0-9] * ＆安培;然后执行 V $ LINENUMBER 基于命令的一些解析...

---

基于chepner的评论

，这里是更新：

下面添加在你的.bashrc：

 的eval`声明-f command_not_found_handle | sed的S / command_not_found_handle / command_not_found_handle_orig /`command_not_found_handle（）{
    如果expr匹配$ 1V [0-9] *＆GT;的/ dev / null的;然后
       V $ {1：1}
       返回$？
    科幻
    command_not_found_handle_orig$ [@]
}
 

I need to view a specific line of a log file from time to time:

$ head -10 log.txt|tail -1  # to view line 10 of log.txt

Then I wrote a function v in my bashrc to make life easier:

$ v 10

Ok, maybe I'm a little splitting hair here: I'd like to ignore the space too:

$ v10

The only way I know is to define lots of alias:

alias v1='v 1'
alias v2='v 2'
alias v3='v 3'
alias v4='v 4'
...

Is there any good way for this?

---

Thanks @Chirlo and @anishsane for the idea.

Here is my final version, based on @anishsane's with some fixes:

eval "`declare -f command_not_found_handle | sed s/command_not_found_handle/command_not_found_handle_orig/`"
command_not_found_handle(){
    if expr match "$1" "v[0-9][0-9]*" >/dev/null ; then
       v ${1:1}
       return $?
    fi
    command_not_found_handle_orig "$@"
}

解决方案

This is not an answer, but a hint:

When you give some command on ubuntu, & if that program is not installed, then the shell calls its own handler, saying

The program 'something' is currently not installed. You can install it by typing:
sudo apt-get install something

You can try finding that piece of program, which does this. Then hook your code, which would look if command is matching regex v[0-9]* & then execute v $lineNumber based on some parsing of command...

---

Based on chepner's comment, here is the update:

Add below in your .bashrc:

eval "`declare -f command_not_found_handle | sed s/command_not_found_handle/command_not_found_handle_orig/`"

command_not_found_handle(){
    if expr match "$1" "v[0-9]*" >/dev/null ; then
       v ${1:1}
       return $?
    fi
    command_not_found_handle_orig "$[@]"
}

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