blocks|key|241376|text|您可以使用<<<来获得此行为。read+<<<+echo+"text"应该能成功。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|241377|使用readly进行测试(我不喜欢使用保留字)：|241378|function+readly()
{
+echo+$*
+echo+"this+was+a+test"
}

$+readly+<<<+echo+"hello"
hello
this+was+a+test|code-block|syntax|javascript|241379|使用管道，基于this+answer+to+"Bash+script,+read+values+from+stdin+pipe"|241380|$+echo+"hello+bye"+%7C+{+read+a;+echo+$a;++echo+"this+was+a+test";+}
hello+bye
this+was+a+test|241381|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/6779351/1983854^0|5|3|F|K|0|2|6|0|0|7|1L|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|13|8|@$9|14|A|15|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|16|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|17|8|@]|D|@$9|18|A|19|1|1A]]|E|$]]|$1|O|3|P|5|J|7|1B|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|1C|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]]]

You can use <code>&lt;&lt;&lt;</code> to get this behaviour. <code>read &lt;&lt;&lt; echo "text"</code> should make it.

Test with <code>readly</code> (I prefer not using reserved words):

<pre><code>function readly()
{
 echo $*
 echo "this was a test"
}

$ readly &lt;&lt;&lt; echo "hello"
hello
this was a test
</code></pre>

With pipes, based on <a href="https://stackoverflow.com/a/6779351/1983854">this answer to "Bash script, read values from stdin pipe"</a>:

<pre><code>$ echo "hello bye" | { read a; echo $a; echo "this was a test"; }
hello bye
this was a test
</code></pre>

blocks|key|241416|text|下面是使用printf和标准输入的bash中sprintf函数的实现示例：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|241417|sprintf()+{+local+stdin;+read+-d+''+-u+0+stdin;+printf+"$@"+"$stdin";+}|code-block|syntax|javascript|241418|示例用法：|241419|$+echo+bar+%7C+sprintf+"foo+%25s"
foo+bar|241420|这将使您了解函数如何从标准输入中读取。|241421|entityMap^0|5|6|M|7|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|10|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

Here is example implementation of <code>sprintf</code> function in bash which uses <code>printf</code> and standard input:

<pre><code>sprintf() { local stdin; read -d '' -u 0 stdin; printf "$@" "$stdin"; }
</code></pre>

Example usage:

<pre><code>$ echo bar | sprintf "foo %s"
foo bar
</code></pre>

This would give you an idea how function can read from standard input.

blocks|key|24824|text|我发现使用test和awk可以在一行内完成这项工作……|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|24825|++++test+-p+/dev/stdin++&&+awk+'{print}'+/dev/stdin|code-block|syntax|javascript|24826|test+-p测试管道上的输入，管道通过标准输入接受输入。只有当输入存在时，我们才想要运行awk，否则它将无限期地挂起，等待永远不会到来的输入。|24827|我已经将其放入一个函数中，以使其易于使用。|24828|inputStdin+()+{
++test+-p+/dev/stdin++&&+awk+'{print}'+/dev/stdin++&&+return+0
++###+accepts+input+if+any+but+does+not+hang+waiting+for+input
++#
++return+1
}|24829|用法...|24830|_stdin="$(inputStdin)"|24831|另一个函数在没有测试的情况下使用awk等待命令行输入...|24832|inputCli+()+{
++local+_input=""
++local+_prompt="$1"
++#
++[[+"$_prompt"+]]++&&+{+printf+"%25s"+"$_prompt"+>+/dev/tty;+}
++###+no+prompt+at+all+if+none+supplied
++#
++_input="$(awk+'BEGIN+{getline+INPUT+<+"/dev/tty";+print+INPUT}')"
++###+accept+input+(used+in+place+of+'read')
++###+++put+in+a+BEGIN+section+so+will+only+accept+1+line+and+exit+on+ENTER
++###+++WAITS+INDEFINITELY+FOR+INPUT
++#
++[[+"$_input"+]]++&&+{+printf+"%25s"+"$_input";+return+0;+}
++#
++return+1
}|24833|24834|_userinput="$(inputCli+"Prompt+string:+")"|24835|请注意，第一个printf上的>+/dev/tty似乎是在命令替代$(...)中调用函数时打印提示所必需的。|24836|这种awk的使用允许消除用于从键盘或标准输入收集输入的奇怪的read命令。|24837|entityMap^0|5|4|A|3|0|0|0|7|19|3|0|0|0|0|0|0|0|0|0|7|6|F|A|X|6|0|2|3|U|4|0^^$0|@$1|2|3|4|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|1C|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1D|8|@$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|M|3|N|5|6|7|1I|8|@]|D|@]|E|$]]|$1|O|3|P|5|H|7|1J|8|@]|D|@]|E|$I|J]]|$1|Q|3|R|5|6|7|1K|8|@]|D|@]|E|$]]|$1|S|3|T|5|H|7|1L|8|@]|D|@]|E|$I|J]]|$1|U|3|V|5|6|7|1M|8|@]|D|@]|E|$]]|$1|W|3|X|5|H|7|1N|8|@]|D|@]|E|$I|J]]|$1|Y|3|R|5|6|7|1O|8|@]|D|@]|E|$]]|$1|Z|3|10|5|H|7|1P|8|@]|D|@]|E|$I|J]]|$1|11|3|12|5|6|7|1Q|8|@$9|1R|A|1S|B|C]|$9|1T|A|1U|B|C]|$9|1V|A|1W|B|C]]|D|@]|E|$]]|$1|13|3|14|5|6|7|1X|8|@$9|1Y|A|1Z|B|C]|$9|20|A|21|B|C]]|D|@]|E|$]]|$1|15|3|-4|5|6|7|22|8|@]|D|@]|E|$]]]|16|$]]

I've discovered that this can be done in one line using <code>test</code> and <code>awk</code>...

<pre><code> test -p /dev/stdin &amp;&amp; awk '{print}' /dev/stdin
</code></pre>

The <code>test -p</code> tests for input on a pipe, which accepts input via stdin. Only if input is present do we want to run the <code>awk</code> since otherwise it will hang indefinitely waiting for input which will never come.

I've put this into a function to make it easy to use...

<pre><code>inputStdin () {
 test -p /dev/stdin &amp;&amp; awk '{print}' /dev/stdin &amp;&amp; return 0
 ### accepts input if any but does not hang waiting for input
 #
 return 1
}
</code></pre>

Usage...

<pre><code>_stdin="$(inputStdin)"
</code></pre>

Another function uses awk without the test to wait for commandline input...

<pre><code>inputCli () {
 local _input=""
 local _prompt="$1"
 #
 [[ "$_prompt" ]] &amp;&amp; { printf "%s" "$_prompt" &gt; /dev/tty; }
 ### no prompt at all if none supplied
 #
 _input="$(awk 'BEGIN {getline INPUT &lt; "/dev/tty"; print INPUT}')"
 ### accept input (used in place of 'read')
 ### put in a BEGIN section so will only accept 1 line and exit on ENTER
 ### WAITS INDEFINITELY FOR INPUT
 #
 [[ "$_input" ]] &amp;&amp; { printf "%s" "$_input"; return 0; }
 #
 return 1
}
</code></pre>

Usage...

<pre><code>_userinput="$(inputCli "Prompt string: ")"
</code></pre>

Note that the <code>&gt; /dev/tty</code> on the first <code>printf</code> seems to be necessary to get the prompt to print when the function is called in a Command Substituion <code>$(...)</code>.

This use of <code>awk</code> allows the elimination of the quirky <code>read</code> command for collecting input from keyboard or stdin.

I have some scripts that work with parameters, they work just fine but i would like them to be able to read from stdin, from a pipe for example, an example, suppose this is called read:

<pre><code>#!/bin/bash
function read()
{
 echo $*
}

read $*
</code></pre>

Now this works with <code>read "foo" "bar"</code>, but I would like to use it as:

<pre><code>echo "foo" | read
</code></pre>

How do I accomplish this?

How to make a bash function which can read from standard input?

我有一些使用参数的脚本，它们工作得很好，但我希望它们能够从stdin中读取，例如，从管道中读取，例如，假设这称为read：#!/bin/bashfunction read(){ echo $*}read $*现在，这可以与read "foo" "bar"一起使用，但我想将其用作：echo "foo" | read我该如...

问如何创建一个可以从标准输入读取的bash函数？
EN

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问如何创建一个可以从标准输入读取的bash函数？
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