php shell exec acting different to running command directly - php

Question

I have a php script that attempts to remove all files from a directory structure, but preserve everything in svn. I found this command online which does the job perfectly if you plug it directly in a shell
find /my/folder/path/ -path \'*/.svn\' -prune -o -type f -exec rm {} +
Unfortunately if I perform a shell_exec in php on that command like so:
$cmd = 'find $folderPath -path \'*/.svn\' -prune -o -type f -exec rm {} +';
shell_exec($cmd);
Then all the files in my current directory that I call the php script from are deleted as well.
Can someone explain why, and how to fix the issue so that I can fix the php script so it acts like expected, removing only those files in the specified folder
The full source code is below, just in case there is perhaps a silly mistake in there that I have missed:
<?php
# This script simply removes all files from a specified folder, that aren't directories or .svn
# files. It will see if a folder path was given as a cli parameter, and if not, ask the user if they
# want to remove the files in their current directory.
$execute = false;
if (isset($argv[1]))
{
$folderPath = $argv[1];
$execute = true;
}
else
{
$folderPath = getcwd();
$answer = readline("Remove all files but not folders or svn files in $folderPath (y/n)?" . PHP_EOL);
if ($answer == 'Y' || $answer == 'y')
{
$execute = true;
}
}
if ($execute)
{
# Strip out the last / if it was given by accident as this can cause deletion of wrong files
if (substr($folderPath, -1) != '/')
{
$folderPath .= "/";
}
print "Removing files from $folderPath" . PHP_EOL;
$cmd = 'find $folderPath -path \'*/.svn\' -prune -o -type f -exec rm {} +';
shell_exec($cmd);
}
else
{
print "Ok not bothering." . PHP_EOL;
}
print "Done" . PHP_EOL;
?>

Answer 1

Your command looks okay. At least in shell. If you would actually troubleshoot your issue in PHP with a simple
var_dump($cmd);
You would see where your error lies:
$cmd = 'find $folderPath -path \'*/.svn\' -prune -o -type f -exec rm {} +';
Look closely. Hint: A single can't make a double for a dollar.

Answer 2

It all comes down to:
$cmd = 'find $folderPath -path \'*/.svn\' -prune -o -type f -exec rm {} +';
shell_exec($cmd);
Since you are using single quotes the variable $folderPath is not changed. So you are executing
find $folderPath -path '*/.svn' -prune -o -type f -exec rm {} +
instead of
find /my/folder/path/ -path \'*/.svn\' -prune -o -type f -exec rm {} +
use double quotes or $cmd = 'find '.$folderPath.' -path \'*/.svn\' -prune -o -type f -exec rm {} +';