blocks|key|2529023|text|定义别名时，变量dl正确为空。它将扩大到：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2529024|alias+dm="git+diff+master+>++&&+subl+"|code-block|syntax|javascript|2529025|当使用别名时，使用单引号而不是双引号将允许变量展开：|2529026|alias+dm='git+diff+master+>+"$dl"+&&+subl+"$dl"'|2529027|现在，当在命令行上键入dl时，扩展了dm变量：|2529028|%25+dl=hello
%25+dm+->+git+diff+master+>+hello+&&+subl+hello
%25+dl=world
%25+dm+->+git+diff+master+>+world+&&+subl+world|2529029|还请注意，我在$dl周围添加了引号，以避免分词和全球化。|2529030|您可以考虑使用函数而不是别名，IMO别名用于为ls、grep等添加颜色。|2529031|alias+ls='ls+--color=auto'|2529032|函数用于运行更复杂的命令：|2529033|dm()+{
++git+diff+master+>+"$dl"
++subl+"$dl"
+}|2529034|顺便说一下。许多命令支持-标志，它告诉输入是从stdin开始的，所以下面的命令可能会工作：|2529035|+dm()+{
+++git+diff+master+%7C+subl+-
+}|2529036|entityMap^0|8|2|0|0|0|0|B|2|I|2|0|0|7|3|0|0|0|0|0|C|1|0|0^^$0|@$1|2|3|4|5|6|7|18|8|@$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1C|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1D|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1E|8|@$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|H|7|1J|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|1K|8|@$9|1L|A|1M|B|C]]|D|@]|E|$]]|$1|U|3|V|5|6|7|1N|8|@]|D|@]|E|$]]|$1|W|3|X|5|H|7|1O|8|@]|D|@]|E|$I|J]]|$1|Y|3|Z|5|6|7|1P|8|@]|D|@]|E|$]]|$1|10|3|11|5|H|7|1Q|8|@]|D|@]|E|$I|J]]|$1|12|3|13|5|6|7|1R|8|@$9|1S|A|1T|B|C]]|D|@]|E|$]]|$1|14|3|15|5|H|7|1U|8|@]|D|@]|E|$I|J]]|$1|16|3|-4|5|6|7|1V|8|@]|D|@]|E|$]]]|17|$]]

Your variable <code>dl</code> is properly empty when your alias is defined. And it will expand to:

<pre><code>alias dm="git diff master &gt; &amp;&amp; subl "
</code></pre>

Using single quotes instead of double quotes will let the variable expansion happen when the alias is used:

<pre><code>alias dm='git diff master &gt; "$dl" &amp;&amp; subl "$dl"'
</code></pre>

Now the <code>dl</code> variable is expanded when <code>dm</code> is typed on the command line:

<pre><code>% dl=hello
% dm -&gt; git diff master &gt; hello &amp;&amp; subl hello
% dl=world
% dm -&gt; git diff master &gt; world &amp;&amp; subl world
</code></pre>

Also note that I added quotes around <code>$dl</code> to avoid word splitting and globbing.

You might consider using a function instead of an alias, IMO aliases are for stuff like adding color to ls, grep etc...

<pre><code>alias ls='ls --color=auto'
</code></pre>

While functions are for running more complex command:

<pre><code>dm() {
 git diff master &gt; "$dl"
 subl "$dl"
 }
</code></pre>

BTW. Many commands support the <code>-</code> flag which tells that the input is comming from stdin, so the following might work:

<pre><code> dm() {
 git diff master | subl -
 }
</code></pre>

blocks|key|1666543|text|您已经在dl脚本的末尾定义了.bash_profile。这是否意味着dl是在dm别名之后导出的？|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1666544|尝试交换这两个命令，以便首先导出dl，然后在设置dm别名时，它将继承dl变量。|1666545|它在资源获取后工作的原因是，初始终端登录将来源于dl变量，然后手动source将使用不久前定义的dl变量重置别名。|1666546|entityMap^0|4|2|E|D|Y|2|12|2|0|G|2|O|2|Y|2|0|O|2|X|6|1C|2|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|11|8|@$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]]|D|@]|E|$]]|$1|J|3|-4|5|6|7|18|8|@]|D|@]|E|$]]]|K|$]]

You said that you have defined <code>dl</code> towards the end of the <code>.bash_profile</code> script. Does this mean that <code>dl</code> is exported after your <code>dm</code> alias?

Try swapping the two commands around so <code>dl</code> is exported first, then when your <code>dm</code> alias is set, it will inherit the <code>dl</code> variable.

The reason why it works after sourcing is because the initial terminal log in will source the <code>dl</code> variable, and then your manual <code>source</code> will then reset the alias with the <code>dl</code> variable that was defined shortly before.

This alias is giving me trouble:

<pre><code>alias dm="git diff master &gt; $dl &amp;&amp; subl $dl"
</code></pre>

If I run <code>source ~/.bash_profile</code>, then it works. But if I just open the terminal and run <code>dm</code> without sourcing first, I get:

<pre><code>-bash: syntax error near unexpected token `&amp;&amp;'
</code></pre>

If I restart the terminal after sourcing, it doesn't work again. What's the issue here? <code>$dl</code> is this, defined near the end of bash_profile:

<pre><code>export dl=~/"Desktop/Diffs/today.diff"
</code></pre>

(I'm on Ubuntu 12.04. Unlikely relevant, but even so.)

Why am I getting a syntax error from my alias if I don't re-source my bash_profile?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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这个化名给我带来了麻烦：alias dm="git diff master > $dl && subl $dl"如果我运行source ~/.bash_profile，那么它就能工作。但是，如果我只是打开终端，运行dm，而没有先采购，我得到：-bash: syntax error near unexpected tok...

问如果我不重新来源我的bash_profile，为什么我会从别名中得到语法错误？
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问如果我不重新来源我的bash_profile，为什么我会从别名中得到语法错误？EN