From: scope at planetavent dot de
Operating system: Linux, Windows
PHP version: 5.3.1
PHP Bug Type: Program Execution
Bug description: exec() adds single byte twice to $output array
Description:
------------
If exec is used to start a command that outputs only a single byte, and if
the $output array is used, the byte is added twice to the output array.
Tested with php 5.3.1 in cli mode on Windows 2003 Server and Ubuntu 9.10
Server.
This behaviour was introduced with bugfix to #49847:
>From exec.c:125
while (php_stream_get_line(stream, b, EXEC_INPUT_BUF, &bufl)) {
...
if (b[bufl - 1] != '\n' && !php_stream_eof(stream)) {
...
continue;
If only a single byte is read, php_stream_eof(stream) returns true, thus
no second loop will take place.
After line 149:
while (l-- && isspace(((unsigned char *)buf)[l]));
buflen is 1 and l is 0, therefor
line 160:
if ((type == 2 && bufl && !l) || type != 2) {
yields true and the buffer is added to the output array, again.
Reproduce code:
---------------
<?php
$command = "echo x";
exec( $command, $output );
print_r( $output );
Expected result:
----------------
Array
(
[0] => x
)
Actual result:
--------------
Array
(
[0] => x
[1] => x
)
--
Edit bug report at http://bugs.php.net/?id=50732&edit=1
--
Try a snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=50732&r=trysnapshot52
Try a snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=50732&r=trysnapshot53
Try a snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=50732&r=trysnapshot60
Fixed in SVN:
http://bugs.php.net/fix.php?id=50732&r=fixed
Fixed in SVN and need be documented:
http://bugs.php.net/fix.php?id=50732&r=needdocs
Fixed in release:
http://bugs.php.net/fix.php?id=50732&r=alreadyfixed
Need backtrace:
http://bugs.php.net/fix.php?id=50732&r=needtrace
Need Reproduce Script:
http://bugs.php.net/fix.php?id=50732&r=needscript
Try newer version:
http://bugs.php.net/fix.php?id=50732&r=oldversion
Not developer issue:
http://bugs.php.net/fix.php?id=50732&r=support
Expected behavior:
http://bugs.php.net/fix.php?id=50732&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=50732&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=50732&r=submittedtwice
register_globals:
http://bugs.php.net/fix.php?id=50732&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=50732&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=50732&r=dst
IIS Stability:
http://bugs.php.net/fix.php?id=50732&r=isapi
Install GNU Sed:
http://bugs.php.net/fix.php?id=50732&r=gnused
Floating point limitations:
http://bugs.php.net/fix.php?id=50732&r=float
No Zend Extensions:
http://bugs.php.net/fix.php?id=50732&r=nozend
MySQL Configuration Error:
http://bugs.php.net/fix.php?id=50732&r=mysqlcfg
