#35161 [Opn]: Inaccurate documentation about popen() escaping in safe_mode

ID: 35161 Updated by: vrana@php.net Reported By: brion at pobox dot com Status: Open Bug Type: Documentation problem Operating System: Mac OS X PHP Version: Irrelevant New Comment: Snippet changed to: "With safe mode enabled, the command string is escaped with escapeshellcmd(). Thus, echo y | echo x becomes echo y \| echo x." There's really no way to echo '-=< Test >=-' in safe_mode so I have reopened the bug #32701. I'm leaving this one open until 32701 will be resolved to document the final state. Previous Comments: ------------------------------------------------------------------------ [2005-11-09 03:28:34] brion at pobox dot com Description: ------------ This bug was reported some months ago about odd escaping in popen() when safe_mode is on: http://bugs.php.net/bug.php?id=32701 Arguments correctly escaped, as with escapeshellarg(), end up being unexpectedly corrupted under safe_mode with the addition of unexpected backslashes. The bug was marked as BOGUS. If it this is the intended behavior, the documentation needs to be modified to reflect this. Currently the docs for popen() and several other functions include only this caveat: "With safe mode enabled, all words following the initial command string are treated as a single argument. Thus, echo y | echo x becomes echo "y | echo x"." However that is *false*: 1) Multiple arguments are sent where separated by spaces. 2) Quotes seem to be understood, so multi-word arguments are themselves passed intact. 3) In addition to this sensible behavior, many characters have backslashes inserted before them, even if they are inside already-quoted arguments. Accurate documentation, and an explanation of how to get parameters to the other program without corruption, would be a huge help in making our programs work correctly under safe_mode. cf http://bugzilla.wikimedia.org/show_bug.cgi?id=3891#c13 Reproduce code: --------------- <?php $r = popen("echo '-=< Test >=-'", "r"); print(stream_get_contents($r)); pclose($r); ?> Expected result: ---------------- -=< Test >=- Actual result: -------------- -=\< Test \>=- ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=35161&edit=1