创建一个带参数的Bash别名？

我曾经使用CShell（csh），它允许您创建一个接受参数的别名。符号有点像

alias junk="mv \\!* ~/.Trash"

在巴什，这似乎行不通。鉴于Bash有许多有用的特性，我会假设这一特性已经实现，但我想知道如何实现。

当前回答

注意：如果这个想法不明显，除了别名之外，使用别名是一个坏主意，第一个是“别名中的函数”，第二个是“难以读取的重定向/源”。此外，还有一些缺陷（我认为这是显而易见的，但以防万一你会感到困惑：我并不是说它们真的可以在任何地方使用！）

我以前回答过这个问题，过去总是这样：

alias foo='__foo() { unset -f $0; echo "arg1 for foo=$1"; }; __foo()'

这是很好的，除非你避免一起使用函数。在这种情况下，您可以利用bash强大的重定向文本的能力：

alias bar='cat <<< '\''echo arg1 for bar=$1'\'' | source /dev/stdin'

它们的长度大致相同，只需几个字符即可。

真正的关键是时间差，顶部是“函数方法”，底部是“重定向源”方法。为了证明这一理论，时机不言自明：

arg1 for foo=FOOVALUE
 real 0m0.011s user 0m0.004s sys 0m0.008s  # <--time spent in foo
 real 0m0.000s user 0m0.000s sys 0m0.000s  # <--time spent in bar
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.010s user 0m0.004s sys 0m0.004s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.011s user 0m0.000s sys 0m0.012s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.012s user 0m0.004s sys 0m0.004s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.010s user 0m0.008s sys 0m0.004s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE

这是随机间隔进行的约200个结果的底部。函数创建/销毁似乎比重定向花费更多的时间。希望这将有助于未来的访问者解决这个问题（我不想对自己保密）。

2015-05-20 18:39:37

其他回答

要具体回答有关创建别名以将文件移动到垃圾箱文件夹而不是删除文件的问题，请执行以下操作：

alias rm="mv "$1" -t ~/.Trash/"

当然，你必须先创建dir~/.Trash。

然后只需发出以下命令：

$rm <filename>
$rm <dirname>

2020-06-26 06:46:06

另一种解决方案是使用标记，这是我最近创建的一个工具，它允许您将命令模板“书签”，并轻松地将光标放置在命令占位符处：

我发现，大多数时候，我都在使用shell函数，所以我不必在命令行中一次又一次地编写常用命令。在这个用例中使用函数的问题是在我的命令词汇表中添加新的术语，并且必须记住实际命令中的函数参数。标记目标是消除这种心理负担。

2015-05-22 12:39:43

我以前回答过这个问题，过去总是这样：

alias foo='__foo() { unset -f $0; echo "arg1 for foo=$1"; }; __foo()'

这是很好的，除非你避免一起使用函数。在这种情况下，您可以利用bash强大的重定向文本的能力：

alias bar='cat <<< '\''echo arg1 for bar=$1'\'' | source /dev/stdin'

它们的长度大致相同，只需几个字符即可。

真正的关键是时间差，顶部是“函数方法”，底部是“重定向源”方法。为了证明这一理论，时机不言自明：

arg1 for foo=FOOVALUE
 real 0m0.011s user 0m0.004s sys 0m0.008s  # <--time spent in foo
 real 0m0.000s user 0m0.000s sys 0m0.000s  # <--time spent in bar
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.010s user 0m0.004s sys 0m0.004s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.011s user 0m0.000s sys 0m0.012s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.012s user 0m0.004s sys 0m0.004s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE
ubuntu@localhost /usr/bin# time foo FOOVALUE; time bar BARVALUE
arg1 for foo=FOOVALUE
 real 0m0.010s user 0m0.008s sys 0m0.004s
 real 0m0.000s user 0m0.000s sys 0m0.000s
arg1 for bar=BARVALUE

2015-05-20 18:39:37

下面是我的~/.bashrc中的三个函数示例，它们本质上是接受参数的别名：

#Utility required by all below functions.
#https://stackoverflow.com/questions/369758/how-to-trim-whitespace-from-bash-variable#comment21953456_3232433
alias trim="sed -e 's/^[[:space:]]*//g' -e 's/[[:space:]]*\$//g'"

:<<COMMENT
    Alias function for recursive deletion, with are-you-sure prompt.

    Example:
        srf /home/myusername/django_files/rest_tutorial/rest_venv/

    Parameter is required, and must be at least one non-whitespace character.

    Short description: Stored in SRF_DESC

    With the following setting, this is *not* added to the history:
        export HISTIGNORE="*rm -r*:srf *"
    - https://superuser.com/questions/232885/can-you-share-wisdom-on-using-histignore-in-bash

    See:
    - y/n prompt: https://stackoverflow.com/a/3232082/2736496
    - Alias w/param: https://stackoverflow.com/a/7131683/2736496
COMMENT
#SRF_DESC: For "aliaf" command (with an 'f'). Must end with a newline.
SRF_DESC="srf [path]: Recursive deletion, with y/n prompt\n"
srf()  {
    #Exit if no parameter is provided (if it's the empty string)
        param=$(echo "$1" | trim)
        echo "$param"
        if [ -z "$param" ]  #http://tldp.org/LDP/abs/html/comparison-ops.html
        then
          echo "Required parameter missing. Cancelled"; return
        fi

    #Actual line-breaks required in order to expand the variable.
    #- https://stackoverflow.com/a/4296147/2736496
    read -r -p "About to
    sudo rm -rf \"$param\"
Are you sure? [y/N] " response
    response=${response,,}    # tolower
    if [[ $response =~ ^(yes|y)$ ]]
    then
        sudo rm -rf "$param"
    else
        echo "Cancelled."
    fi
}

:<<COMMENT
    Delete item from history based on its line number. No prompt.

    Short description: Stored in HX_DESC

    Examples
        hx 112
        hx 3

    See:
    - https://unix.stackexchange.com/questions/57924/how-to-delete-commands-in-history-matching-a-given-string
COMMENT
#HX_DESC: For "aliaf" command (with an 'f'). Must end with a newline.
HX_DESC="hx [linenum]: Delete history item at line number\n"
hx()  {
    history -d "$1"
}

:<<COMMENT
    Deletes all lines from the history that match a search string, with a
    prompt. The history file is then reloaded into memory.

    Short description: Stored in HXF_DESC

    Examples
        hxf "rm -rf"
        hxf ^source

    Parameter is required, and must be at least one non-whitespace character.

    With the following setting, this is *not* added to the history:
        export HISTIGNORE="*hxf *"
    - https://superuser.com/questions/232885/can-you-share-wisdom-on-using-histignore-in-bash

    See:
    - https://unix.stackexchange.com/questions/57924/how-to-delete-commands-in-history-matching-a-given-string
COMMENT
#HXF_DESC: For "aliaf" command (with an 'f'). Must end with a newline.
HXF_DESC="hxf [searchterm]: Delete all history items matching search term, with y/n prompt\n"
hxf()  {
    #Exit if no parameter is provided (if it's the empty string)
        param=$(echo "$1" | trim)
        echo "$param"
        if [ -z "$param" ]  #http://tldp.org/LDP/abs/html/comparison-ops.html
        then
          echo "Required parameter missing. Cancelled"; return
        fi

    read -r -p "About to delete all items from history that match \"$param\". Are you sure? [y/N] " response
    response=${response,,}    # tolower
    if [[ $response =~ ^(yes|y)$ ]]
    then
        #Delete all matched items from the file, and duplicate it to a temp
        #location.
        grep -v "$param" "$HISTFILE" > /tmp/history

        #Clear all items in the current sessions history (in memory). This
        #empties out $HISTFILE.
        history -c

        #Overwrite the actual history file with the temp one.
        mv /tmp/history "$HISTFILE"

        #Now reload it.
        history -r "$HISTFILE"     #Alternative: exec bash
    else
        echo "Cancelled."
    fi
}

参考文献：

从字符串中删除空白：如何从Bash变量中删除空白？实际换行符：https://stackoverflow.com/a/4296147/2736496别名w/param：https://stackoverflow.com/a/7131683/2736496（这个问题的另一个答案）组氨酸：https://superuser.com/questions/232885/can-you-share-wisdom-on-using-histignore-in-bashY/N提示：https://stackoverflow.com/a/3232082/2736496从历史记录中删除所有匹配项：https://unix.stackexchange.com/questions/57924/how-to-delete-commands-in-history-matching-a-given-string字符串是否为空：http://tldp.org/LDP/abs/html/comparison-ops.html

2015-01-13 03:57:19

这是另一种使用read的方法。我使用这个方法通过名称片段对文件进行暴力搜索，忽略了“拒绝权限”消息。

alias loc0='( IFS= read -r x; find . -iname "*" -print 2>/dev/null | grep $x;) <<<'

一个简单的例子：

$ ( IFS= read -r x; echo "1 $x 2 ";) <<< "a b"
1 a b 2

注意，这将参数作为字符串转换为变量。可以在引号中使用多个参数，以空格分隔：

$ ( read -r x0 x1; echo "1 ${x0} 2 ${x1} 3 ";) <<< "a b"
1 a 2 b 3

2021-01-19 10:02:43

创建一个带参数的Bash别名？

推荐文章

最新文章

标签