blocks|key|572229|text|printf+'%25s\n%25s\n'+"to+be+prepended"+"$(cat+text.txt)"+>text.txt|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|572230|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>printf '%s\n%s\n' "to be prepended" "$(cat text.txt)" &gt;text.txt
</code></pre>

blocks|key|572067|text|这是一种可能性：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|572068|(echo+"to+be+prepended";+cat+text.txt)+>+newfile.txt|code-block|syntax|javascript|572069|您可能不容易绕过中间文件。|572070|替代方案(使用shell转义可能会很麻烦)：|572071|sed+-i+'0,/%5E/s//to+be+prepended/'+text.txt|572072|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

This is one possibility:

<pre><code>(echo "to be prepended"; cat text.txt) &gt; newfile.txt
</code></pre>

you'll probably not easily get around an intermediate file.

Alternatives (can be cumbersome with shell escaping):

<pre><code>sed -i '0,/^/s//to be prepended/' text.txt
</code></pre>

blocks|key|356412|text|这将用于形成输出。-表示标准输入，通过echo中的管道提供。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356413|echo+-e+"to+be+prepended+\n+another+line"+%7C+cat+-+text.txt|code-block|syntax|javascript|356414|要重写文件，需要一个临时文件，因为它不能通过管道返回到输入文件。|356415|echo+"to+be+prepended"+%7C+cat+-+text.txt+>+text.txt.tmp
mv+text.txt.tmp+text.txt|356416|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

This will work to form the output. The - means standard input, which is provide via the pipe from echo.

<pre><code>echo -e "to be prepended \n another line" | cat - text.txt
</code></pre>

To rewrite the file a temporary file is required as cannot pipe back into the input file.

<pre><code>echo "to be prepended" | cat - text.txt &gt; text.txt.tmp
mv text.txt.tmp text.txt
</code></pre>

blocks|key|572430|text|更喜欢亚当的answer|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|572431|我们可以让sponge更容易使用。现在我们不需要创建一个临时文件并重命名为|572432|echo+-e+"to+be+prepended+\n+another+line"+%7C+cat+-+text.txt+%7C+sponge+text.txt|code-block|syntax|javascript|572433|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/10587718/3675670|1|http://linux.die.net/man/1/sponge^0|6|6|0|0|5|6|1|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|F|3|G|5|H|7|12|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|13|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]|S|$5|N|O|P|C|$Q|T]]]]

Prefer Adam's <a href="https://stackoverflow.com/a/10587718/3675670">answer</a>

We can make it easier to use <a href="http://linux.die.net/man/1/sponge" rel="noreferrer">sponge</a>. Now we don't need to create a temporary file and rename it by 

<pre><code>echo -e "to be prepended \n another line" | cat - text.txt | sponge text.txt
</code></pre>

blocks|key|356283|text|可能没有内置的东西，但您可以很容易地编写自己的代码，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356284|#!/bin/bash
echo+-n+"$1"+>+/tmp/tmpfile.$$
cat+"$2"+>>+/tmp/tmpfile.$$
mv+/tmp/tmpfile.$$+"$2"|code-block|syntax|javascript|356285|至少像这样的东西。|356286|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Probably nothing built-in, but you could write your own pretty easily, like this:

<pre class="lang-bsh prettyprint-override"><code>#!/bin/bash
echo -n "$1" &gt; /tmp/tmpfile.$$
cat "$2" &gt;&gt; /tmp/tmpfile.$$
mv /tmp/tmpfile.$$ "$2"
</code></pre>

Something like that at least...

blocks|key|572209|text|使用sed的另一种方式|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|572210|sed+-i.old+'1+{i+to+be+prepended
}'+inFile|code-block|syntax|javascript|572211|如果要预置的行是多行：|572212|sed+-i.old+'1+{i\+
to+be+prepended\
multiline
}'+inFile|572213|entityMap^0|2|3|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

Another way using <code>sed</code>:

<pre><code>sed -i.old '1 {i to be prepended
}' inFile
</code></pre>

If the line to be prepended is multiline:

<pre><code>sed -i.old '1 {i\ 
to be prepended\
multiline
}' inFile
</code></pre>

blocks|key|356689|text|在某些情况下，预置文本只能从标准输入中获得。那么这个组合就会起作用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356690|echo+"to+be+prepended"+%7C+cat+-+text.txt+%7C+tee+text.txt|code-block|syntax|javascript|356691|如果您想省略tee输出，则追加>+/dev/null。|offset|length|style|CODE|356692|entityMap^0|0|0|6|3|F|B|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

In some circumstances prepended text may available only from stdin.
Then this combination shall work.

<pre><code>echo "to be prepended" | cat - text.txt | tee text.txt
</code></pre>

If you want to omit <code>tee</code> output, then append <code>&gt; /dev/null</code>.

blocks|key|356751|text|解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356752|printf+'%25s\n%25s'+'text+to+prepend'+"$(cat+file.txt)"+>+file.txt|code-block|syntax|javascript|356753|请注意，这在所有类型的输入上都是安全的，因为没有扩展。例如，如果你想在前面加上!@#$%25%5E&*()ugly+text\n\t\n，它就可以工作了：|offset|length|style|CODE|356754|printf+'%25s\n%25s'+'!@#$%25%5E&*()ugly+text\n\t\n'+"$(cat+file.txt)"+>+file.txt|356755|最后要考虑的部分是在命令替换"$(cat+file.txt)"期间删除文件末尾的空格。这方面的所有变通方法都相对复杂。如果您想保留file.txt末尾的换行符，请参阅以下内容：https://stackoverflow.com/a/22607352/1091436|356756|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/22607352/1091436^0|0|0|13|P|0|0|E|H|2G|18|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@$I|11|J|12|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|14|8|@$I|15|J|16|K|L]]|9|@$I|17|J|18|1|19]]|A|$]]|$1|Q|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

Solution:

<pre><code>printf '%s\n%s' 'text to prepend' "$(cat file.txt)" &gt; file.txt
</code></pre>

Note that this is safe on all kind of inputs, because there are no expansions. For example, if you want to prepend <code>!@#$%^&amp;*()ugly text\n\t\n</code>, it will just work:

<pre><code>printf '%s\n%s' '!@#$%^&amp;*()ugly text\n\t\n' "$(cat file.txt)" &gt; file.txt
</code></pre>

The last part left for consideration is whitespace removal at end of file during command substitution <code>"$(cat file.txt)"</code>. All work-arounds for this are relatively complex. If you want to preserve newlines at end of file.txt, see this: <a href="https://stackoverflow.com/a/22607352/1091436">https://stackoverflow.com/a/22607352/1091436</a>

blocks|key|356888|text|在Bash+(在Ubuntu中)中测试，如果从测试文件via开始；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356889|echo+"Original+Line"+>+test_file.txt|offset|length|style|CODE|356890|你可以执行；|356891|echo+"$(echo+"New+Line";+cat+test_file.txt)"+>+test_file.txt|356892|或者，如果bash的版本对于$()来说太旧，您可以使用反引号；|356893|echo+"`echo+"New+Line";+cat+test_file.txt`"+>+test_file.txt|356894|并接收“test_file.txt”的以下内容；|356895|New+Line
Original+Line|code-block|syntax|javascript|356896|没有中间文件，只有bash/echo。|356897|entityMap^0|0|0|10|0|0|0|1O|0|0|0|1N|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@$D|12|E|13|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|14|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|15|8|@$D|16|E|17|F|G]]|9|@]|A|$]]|$1|L|3|M|5|6|7|18|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|19|8|@$D|1A|E|1B|F|G]]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1C|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1D|8|@]|9|@]|A|$U|V]]|$1|W|3|X|5|6|7|1E|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|Z|$]]

As tested in Bash (in Ubuntu), if starting with a test file via;

<code>echo "Original Line" &gt; test_file.txt</code>

you can execute;

<code>echo "$(echo "New Line"; cat test_file.txt)" &gt; test_file.txt</code>

or, if the version of bash is too old for $(), you can use backticks;

<code>echo "`echo "New Line"; cat test_file.txt`" &gt; test_file.txt</code>

and receive the following contents of "test_file.txt";

<pre><code>New Line
Original Line
</code></pre>

No intermediary file, just bash/echo.

blocks|key|356586|text|另一个相当简单的解决方案是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356587|++++$+echo+-e+"string\n"+$(cat+file)|code-block|syntax|javascript|356588|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Another fairly straight forward solution is:

<pre><code> $ echo -e "string\n" $(cat file)
</code></pre>

blocks|key|356527|text|如果您喜欢vi/vim，这可能更适合您的风格。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356528|printf+'0i\n%25s\n.\nwq\n'+prepend-text+%7C+ed+file|code-block|syntax|javascript|356529|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you like vi/vim, this may be more your style.

<pre><code>printf '0i\n%s\n.\nwq\n' prepend-text | ed file
</code></pre>

blocks|key|572787|text|对于想要附加一行或多行文本(带有变量甚至subshell代码)并保持其可读性和格式化的未来读者，您可能会喜欢以下内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|572788|echo+"Lonely+string"+>+my-file.txt|code-block|syntax|javascript|572789|然后运行|572790|cat+<<EOF+>+my-file.txt
Hello,+there!

$(cat+my-file.txt)
EOF|572791|cat+my-file.txt的结果|offset|length|style|CODE|572792|Hello,+there!

Lonely+string|572793|这之所以有效，是因为读取my-file.txt首先发生在一个子subshell中。我一直使用这个技巧将重要的规则附加到Docker容器中的配置文件中，而不是复制整个配置文件。|572794|entityMap^0|0|0|0|0|0|F|0|0|C|B|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@$M|11|N|12|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|14|8|@$M|15|N|16|O|P]]|9|@]|A|$]]|$1|U|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|V|$]]

For future readers who want to append one or more lines of text (with variables or even subshell code) and keep it readable and formatted, you may enjoy this:
<pre><code>echo &quot;Lonely string&quot; &gt; my-file.txt
</code></pre>
Then run
<pre><code>cat &lt;&lt;EOF &gt; my-file.txt
Hello, there!

$(cat my-file.txt)
EOF
</code></pre>
Results of <code>cat my-file.txt</code>:
<pre><code>Hello, there!

Lonely string
</code></pre>
This works because the read of <code>my-file.txt</code> happens first and in a subshell. I use this trick all the time to append important rules to config files in Docker containers rather than copy over entire config files.

blocks|key|357035|text|%25+echo+blaha+>+blaha
%25+echo+fizz+>+fizz
%25+cat+blaha+fizz+>+buzz
%25+cat+buzz+
blaha
fizz|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|357036|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>% echo blaha &gt; blaha
% echo fizz &gt; fizz
% cat blaha fizz &gt; buzz
% cat buzz 
blaha
fizz
</code></pre>

blocks|key|356544|text|#+create+a+file+with+content..
echo+foo+>+/tmp/foo
#+prepend+a+line+containing+"jim"+to+the+file
sed+-i+"1s/%5E/jim\n/"+/tmp/foo
#+verify+the+content+of+the+file+has+the+new+line+prepened+to+it
cat+/tmp/foo|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|356545|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code># create a file with content..
echo foo &gt; /tmp/foo
# prepend a line containing "jim" to the file
sed -i "1s/^/jim\n/" /tmp/foo
# verify the content of the file has the new line prepened to it
cat /tmp/foo
</code></pre>

blocks|key|356818|text|我建议定义一个函数，然后在需要的地方导入和使用它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356819|prepend_to_file()+{+
++++file=$1
++++text=$2

++++if+!+[[+-f+$file+]]+then
++++++++touch+$file
++++fi

++++echo+"$text"+%7C+cat+-+$file+>+$file.new

++++mv+-f+$file.new+$file
}|code-block|syntax|javascript|356820|然后像这样使用它：|356821|prepend_to_file+test.txt+"This+is+first"
prepend_to_file+test.txt+"This+is+second"|356822|您的文件内容将是：|356823|This+is+second
This+is+first|356824|我将使用这种方法来实现一个更改日志更新器。|356825|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

I'd recommend defining a function and then importing and using that where needed.

<pre><code>prepend_to_file() { 
 file=$1
 text=$2

 if ! [[ -f $file ]] then
 touch $file
 fi

 echo "$text" | cat - $file &gt; $file.new

 mv -f $file.new $file
}
</code></pre>

Then use it like so:

<pre><code>prepend_to_file test.txt "This is first"
prepend_to_file test.txt "This is second"
</code></pre>

Your file contents will then be:

<pre><code>This is second
This is first
</code></pre>

I'm about to use this approach for implementing a change log updater.

blocks|key|356938|text|您可以使用awk轻松地做到这一点|type|unstyled|depth|inlineStyleRanges|entityRanges|data|356939|cat+text.txt%7Cawk+'{print+"to+be+prepended"$0}'|code-block|syntax|javascript|356940|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can do that easily with awk
<pre><code>cat text.txt|awk '{print &quot;to be prepended&quot;$0}'
</code></pre>

Is there a Unix command to prepend some string data to a text file?

Something like:

<pre><code>prepend "to be prepended" text.txt
</code></pre>

Unix command to prepend text to a file

容器

Ubuntu

Unix

是否有一个Unix命令可以将一些字符串数据预先添加到文本文件中？类似于：prepend "to be prepended" text.txt

问用于将文本预先添加到文件的Unix命令
EN

回答 16

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问用于将文本预先添加到文件的Unix命令EN

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问用于将文本预先添加到文件的Unix命令
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