I want to execute a shell command after clicking on a button inside of a html code, so:
我想在单击html代码中的按钮后执行shell命令，所以：
In my html code:
在我的HTML代码中：
<form action=execute.php method="post">
<input name="submit" type="submit" value="Reset">
</form>
execute.php:
execute.php：
<?php
$output = shell_exec("sed -i '2,3d' filename.txt");
//$output = shell_exec("cat filename.txt");
echo "<pre>$output</pre>";
$url = htmlspecialchars($_SERVER['HTTP_REFERER']);
echo "<a href='$url'>Back</a>";
?>
The purpose is to remove all lines of a text file but the very first one.
目的是删除文本文件的所有行，但第一个。
I think that the php code is being properly executed since if I modify the shell command by a simple cat, it works as expected, but I can't figure out why it does nothing when the command to execute is that sed expression.
我认为php代码正在被正确执行，因为如果我通过一个简单的cat修改shell命令，它按预期工作，但是当我执行的命令是sed表达式时，我无法弄清楚为什么它什么都不做。
I've verified that such sed command works when executed directly in CLI and I have also discarded any permissions issue since I chmoded "filename.txt" to 777. In fact if change the php code to append some text to the file it also works. For example:
我已经验证了这样的sed命令在CLI中直接执行时有效，我也放弃了任何权限问题，因为我将“filename.txt”编码为777.实际上如果更改php代码将一些文本附加到文件中它也可以工作。例如：
$output = shell_exec("echo hi >> filename.txt");
After looking for info I realized that what I want can be done directly with php with:
在寻找信息后，我意识到我想要的东西可以直接使用php完成：
file_put_contents("filename.txt", "");
file_put_contents("filename.txt", "First_line_content");
But now I'm just curious about why my sed command didn't work.
但现在我只是好奇为什么我的sed命令不起作用。
I'm running LAMP in an Ubuntu desktop with following sed version:
我正在使用以下sed版本在Ubuntu桌面上运行LAMP：
$ sed --version
sed (GNU sed) 4.2.2
1 个解决方案
#1
1
As sed creates a temp file in the same directory as the file, the script must have write permissions to this directory.
当sed在与文件相同的目录中创建临时文件时，该脚本必须具有对此目录的写入权限。
#1
1
As sed creates a temp file in the same directory as the file, the script must have write permissions to this directory.
当sed在与文件相同的目录中创建临时文件时，该脚本必须具有对此目录的写入权限。