From various Internet posts and recent experience, I have observed that you cannot rely on proc_close returning the accurate return code of the child process. The return code also depends on wether or not you read from the stdout/stderr pipes, as my example shows. I work around this by writing the exit code to an additional file descriptor.
<?
$descriptorspec = array(
0 => array('pipe', 'r'), // stdin is a pipe that the child will read from
1 => array('pipe', 'w'), // stdout is a pipe that the child will write to
2 => array('pipe', 'w'), // stderr is a pipe that the child will write to
);
$proc = @proc_open("/bin/ls -l /etc/passwd", $descriptorspec, $pipes);
fclose($pipes[0]);
$output = array();
while (!feof($pipes[1])) array_push($output, rtrim(fgets($pipes[1],1024),"\n"));
fclose($pipes[1]);
while (!feof($pipes[2])) array_push($output, rtrim(fgets($pipes[2],1024),"\n"));
fclose($pipes[2]);
$exit=proc_close($proc);
print_r($output);
echo "exitcode $exit\n\n";
$descriptorspec = array(
0 => array('pipe', 'r'), // stdin is a pipe that the child will read from
1 => array('pipe', 'w'), // stdout is a pipe that the child will write to
2 => array('pipe', 'w'), // stderr is a pipe that the child will write to
);
$proc = @proc_open("/bin/ls -l /etc/passwd", $descriptorspec, $pipes);
fclose($pipes[0]);
fclose($pipes[1]);
fclose($pipes[2]);
$exit=proc_close($proc);
echo "exitcode $exit\n\n";
$descriptorspec = array(
0 => array('pipe', 'r'), // stdin is a pipe that the child will read from
1 => array('pipe', 'w'), // stdout is a pipe that the child will write to
2 => array('pipe', 'w'), // stderr is a pipe that the child will write to
3 => array('pipe', 'w'), // stderr is a pipe that the child will write to
);
$proc = @proc_open("/bin/ls -l /etc/passwd;echo $? >&3", $descriptorspec, $pipes);
fclose($pipes[0]);
$output = array();
//comment next line to get correct exicode
while (!feof($pipes[1])) array_push($output, rtrim(fgets($pipes[1],1024),"\n"));
fclose($pipes[1]);
while (!feof($pipes[2])) array_push($output, rtrim(fgets($pipes[2],1024),"\n"));
fclose($pipes[2]);
if (!feof($pipes[3])) $output['exitcode']=rtrim(fgets($pipes[3],5),"\n");
fclose($pipes[3]);
proc_close($proc);
print_r($output);
?>
Outputs on my system:
Array
(
[0] => -rw-r--r-- 1 root root 1460 2005-09-02 09:52 /etc/passwd
[1] =>
[2] =>
)
exitcode -1
exitcode 1
Array
(
[0] => -rw-r--r-- 1 root root 1460 2005-09-02 09:52 /etc/passwd
[1] =>
[2] =>
[exitcode] => 0
)
proc_close
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
proc_close — Close a process opened by proc_open() and return the exit code of that process
Descrizione
proc_close() is similar to pclose() except that it only works on processes opened by proc_open(). proc_close() waits for the process to terminate, and returns its exit code. Open pipes to that process are closed when this function is called, in order to avoid a deadlock - the child process may not be able to exit while the pipes are open.
Valori restituiti
Returns the termination status of the process that was run. In case of
an error then -1 is returned.
Nota:
If PHP has been compiled with --enable-sigchild, the return value of this function is undefined.
add a note
User Contributed Notes 5 notes
oohay251 at yahoo dot com ¶
19 years ago
Uwe Ohse ¶
9 years ago
Regarding: "Returns the termination status of the process that was run. In case of an error then -1 is returned."
This is, at best, misleading. It returns:
* -1 on error,
* WEXITSTATUS(status) if WIFEXITED(status) is true, or
* status if WIFEXITED(status) is false,
where status is the status parameter of waitpid().
This makes it impossible to differentiate between a relatively normal exit or a termination by signal, and reduces the value of the proc_close return code to a binary one (ok / something broke).
This can be seen in proc_open_rsrc_dtor() in ext/standard/proc_open.c (PHP 5.4.44, 5.6.12).
ashnazg at php dot net ¶
17 years ago
It seems that if you configured --enable-sigchild when you compiled PHP (which from my reading is required for you to use Oracle stuff), then return codes from proc_close() cannot be trusted.
Using proc_open's Example 1998's code on versions I have of PHP4 (4.4.7) and PHP5 (5.2.4), the return code is always "-1". This is also the only return code I can cause by running other shell commands whether they succeed or fail.
I don't see this caveat mentioned anywhere except on this old bug report -- http://bugs.php.net/bug.php?id=29123
sergey1369 at narod dot ru ¶
21 years ago
Under PHP/4.3.3RC2, in case of two processes
these function may hangs. Work around is not use
proc_close, or put it after all fcloses done.
For example, this code hangs.
$ph1 = proc_open("cat",
array(0=>array("pipe","r"),1=>array("pipe","w")),
$pipes1);
$ph2 = proc_open("cat",
array(0=>array("pipe","r"),1=>array("pipe","w")),
$pipes2);
fclose($pipes1[0]); fclose($pipes1[1]); proc_close($ph1);
fclose($pipes2[0]); fclose($pipes2[1]); proc_close($ph2);
This code worked for me:
$ph1 = proc_open("cat",
array(0=>array("pipe","r"),1=>array("pipe","w")),
$pipes1);
$ph2 = proc_open("cat",
array(0=>array("pipe","r"),1=>array("pipe","w")),
$pipes2);
fclose($pipes1[0]); fclose($pipes1[1]);
fclose($pipes2[0]); fclose($pipes2[1]);
proc_close($ph1); proc_close($ph2);
morrisdavidd at gmail dot com ¶
16 years ago
Consider the following pseudo code:
$SOME_PROCESS = proc_open(/* something here */);
...
$status = proc_get_status($SOME_PROCESS);
...
$exitCode = proc_close($SOME_PROCESS);
If the external program has exited on its own before the call to proc_get_status, then $exitCode == -1
So consider using:
$actualExitCode = ($status["running"] ? $exitCode : $status["exitcode"] );
