使用-r选项的不同PHP结果

Question

PHP appears to be giving different hash values when I use php -r <code> on the command line and when I execute the file with php <file>, php -f <file>, or run the code inside Apache.

For instance, a SHA1 usage on command line using -r:

$ php -r "print sha1('$1S*90');"
77cd8b48ceca53e018f80536b0a44c5b6710425f

When I try the same with file testSHA.php below:

<?php
print sha1('$1S*90');
?>

and run it on command line or inside Apache using mod_php5:

$ php testSHA.php
201cb5aaa7d4db1a49d9be1f2c06d45e4c2a69f2

Strangely, though, the hashes do match using the two methods when I try a different input string such as "123456789".

I don't think I am using a different encoding or character set in the two methods. I also tried using MD5 and still get different hashes on command line with -r and '-f'.

Could someone point out why the hashes would be different using the two methods above? Is there a way to run PHP on command line where I can type the code without entering it in a file, and see output as if it were run inside a file/Apache? I use the command line for quick snippet testing when step-through code debugging is not set up.

Thanks.

PS: I am using PHP 5.2.11 with Suhosin-Patch 0.9.7 (cli) on OpenSUSE 11.1.

Answer 1

When you run $ php -r "print sha1('$1S*90');" on your bash shell, bash is interpreting $1 as a shell variable, which is probably empty unless you have set it.

So PHP sees just this: print sha1('S*90');

The result of which is: 77cd8b48ceca53e018f80536b0a44c5b6710425f, the value you were getting first time. :)

You can escape it like this:

$ php -r "print sha1('\$1S*90');"