|
|
 |
XCV. プログラム実行関数
以下の関数は、システム自体の上でコマンドを実行したり、こうしたコマ
ンドの安全に実行する手段を提供します。
これらの関数は、標準モジュールの一部として利用可能であり、常に使用できます。 これらの関数はPHPコアに含まれるため、使用す
る際にインストールは不要です。 この拡張モジュールは設定ディレクティブを全く定義しません。 この拡張モジュールはリソース型を全く定義しません。
sven at nospam grovestreet dot net
09-Mar-2005 06:42
Hey,
I had this problem: I wanted to kick off a PHP script that would possibly run for a while. This is on a web GUI, so there is the problem of a) the user stopping the browser, and b) reloading or revisiting the page.
Since this will live on a hosted box over which I have little control, am unsure of whether CLI or the CGI is installed, and didn't want to add Perl to the mix, I came up with this hack.
<?
$logfile = dirname(__FILE__)."/mail.log";
if (file_exists ( $logfile )) {
if ( (time() - filectime( $logfile ))<10 ){
header("Refresh: 2; url=''");
print "process running....<br><br>\n\n";
$logcontents = file($logfile);
foreach (array_reverse($logcontents) as $line) {
print $line."<br>\n";
}
} else {
print "process finished!<br><br>\n\n";
$logcontents = file($logfile);
foreach ($logcontents as $line) {
print $line."<br>\n";
}
unlink ($logfile);
}
} else {
echo "\n\n";
echo "startig process...<br><br>\n\n";
ob_flush();
flush();
$log = fopen($logfile, "a") or die("error opening log\n");
set_time_limit(0);
ignore_user_abort(true);
for ($i=0; $i<20; $i++) {
$thisline = "iteration $i";
fputs($log, $thisline."\n");
print $thisline."<br>\n";
ob_flush();
flush();
sleep(1);
}
fclose ($log);
}
?>
This yields:
1st hit:
startig process...
iteration 0
iteration 1
iteration 2
.... adding lines as long as the request is not stopped
on subsequent hits
process running....
iteration 2
iteration 1
iteration 0
and refreshing every 2 secs
and finally:
process finished!
iteration 0
iteration 1
iteration 2
iteration 3
iteration 4
.... rest of log file
Seems to be pretty stable... - any comments in email please.
sven
mr_potty_noodle at hotmail dot com
16-Feb-2005 03:11
You may have issues with RUNAS or CPAU using the exec function on win2k server (Fully patched as of 2005 in my case), Windows 2k3, Windows XP SP2 may require special consideration if your services use the local system account.
It seems Microsoft changed the CreateProcessWithLogonW API call in the backend that makes it incompatible with localsystem account.
This means that some applications WILL NOT RUN, the process will not be created, it will be denied. At first i thought this was a permissions issue, however after looking into it, its clear that it is not.
A solution to the issue is to modify the system service that your web server uses to run from the local system account. In my case this was not an option as the WWW (iss) services on win2k server are integrated with other services which will cause problems.
Microsoft have come up with a solution in a vbs script. The following is a quote from a Microsoft support e-mail, it was aimed at winXP sp2. I have no idea if it will resolve the issue on win2k / win2k3 machines at the moment.
"Thank You for contacting Microsoft Support in regards to your question with CreateProcessWithLogonW() not working on XP SP2 from the localsystem account.
In our internal support database I�ve found the following answer from an American colleague to exactly the same question:
�The code for CreateProcessWithLogonW() was changed in SP2 to have the same behavior as Windows Server 2003. One of the things CreateProcessWithLogonW() will do ensure that the child process has access to the windowstation/desktop if lpDesktop member is specified to NULL or empty string. On Windows XP SP1, the operating system
would grant explicit access to the child process for the windowstation/desktop of the parent process. On Windows XP SP2, the API determines the logon SID of the parent process and adds this to the token of the child process so the API doesn't need to modify the DACLs for the windowstation/desktop. This will not work with the localsystem account since it doesn't have a Logon SID.
If you would like to launch the process interactively (ie winsta0\default) with XP SP2, you'll need to do the following:
1. set lpDesktop to "winsta0\\default".
2. grant the user in the CreateProcessWithLogonW() call access to
"winsta0\\default". The following KB article has sample code on modifying the security using VB:
316440 How To Use Low-Level Access Control APIs from Visual Basic
The function you need to look at is: UpdatePermissionsOfUserObject()
To determine what type of permissions should be granted. Please take a look at the following article:
165194 INFO: CreateProcessAsUser() Windowstations and Desktops
#define WINSTA_ALL (WINSTA_ACCESSCLIPBOARD | WINSTA_ACCESSGLOBALATOMS |
WINSTA_CREATEDESKTOP | WINSTA_ENUMDESKTOPS |
WINSTA_ENUMERATE | WINSTA_EXITWINDOWS |
WINSTA_READATTRIBUTES | WINSTA_READSCREEN |
WINSTA_WRITEATTRIBUTES | DELETE |
READ_CONTROL | WRITE_DAC |
WRITE_OWNER)
#define DESKTOP_ALL (DESKTOP_CREATEMENU | DESKTOP_CREATEWINDOW |
DESKTOP_ENUMERATE | DESKTOP_HOOKCONTROL |
DESKTOP_JOURNALPLAYBACK | DESKTOP_JOURNALRECORD |
DESKTOP_READOBJECTS | DESKTOP_SWITCHDESKTOP |
DESKTOP_WRITEOBJECTS | DELETE |
READ_CONTROL | WRITE_DAC |
WRITE_OWNER)
The values for the above defines are in winuser.h.
I have tested this from localsystem account with XPSP2 and it works using the code from the above article, 165194.�
Shaun
26-Jan-2005 09:53
Trying to use 'exec' to run a helper executable on Win2K3 (and I'm told this also happens on Win2K) from a PHP script running on IIS, failed to invoke the executable.
Running the same PHP script on Win2K using Apache to serve the page calling the same helper executable worked.
Solution: On Win2K3 (and probably Win2K), give the IIS IUSR_xxxxx guest user Read & Execute permissions to Cmd.exe found in the System32 folder under Windows root directory.
This one had me confused longer than it should have! Hope this saves others from the same fate!
louis dot j dot scoras at gmail dot com
23-Jan-2005 06:43
To start a process to run in the background, you can use the same technique you would in writing a daemon. Fork a new child while exiting in the parent, then set that as the process leader. Finally, fork once more, and run whatever the command is:
<?php
if(pcntl_fork()) {
exit;
}
posix_setsid();
if(pcntl_fork()) {
exit;
}
pcntl_exec('/usr/bin/ogg123', array('-q', $this->findPath()));
?>
Of course, this would be the last thing that your script does, because the parent exits when you spawn the new process. You could do more fancy things, but this works as a good starting point.
margus at kohv dot com
18-Jan-2005 11:10
Well, I had this issue when I wanted to start an indefinitely running PERL script from PHP. Somehow I could not make the PHP script to return after executing the PERL script. So finally I came to following solution:
PHP file
-------------------
<?php
exec("perl /home/chatserver.pl > /dev/null");
?>
-------------------
This script will be run over HTTP.
PERL file
-------------------
#!/usr/bin/perl
fork and exit 1;
# normal code here...
-------------------
Hopefully it helps someone :)
Margus
sean @T keenio - dot - com
09-Jan-2005 07:35
Just to clarify, background shell exec()ing is not the same as a fork() under Unix. It would be useful if PHP supported fork() like Perl and other scripting languages do. Simply exec()'ing a process and sending it to the background is not the same.
A true fork() copies the current environment and duplicates the running script so that there are two instances, one child, one parent. The child and parent can determine which copy they are and then take separate courses of execution paths based on that. Often one copy will perform some "busy work" while the other returns to normal execution. But no matter what, both functions live within the same code rather than a separate, external program. exec()ing can not do this for you.
sam at freepeers dot com
02-Oct-2004 12:51
To clarify even more about what has been said in the last few posts:
"exec", "backticks", "system" and so on will fail on Windows 2003 by default.
You must modify the security on cmd.exe to give the user account IUSR-computername the necessary permissions which are at least read & execute.
leaetherstrip at inbox dot ru
08-Jul-2004 09:23
Note on XP users: XP-Home edition does not allow to set rights directly on files and folders. You should use cacls command-line utility to do this.
For example:
cacls c:\windows\system32\cmd.exe /E /G IUSR_ADMIN2003:F
gives IIS user full access to cmd.exe (potential security hole!), so PHP can fork and execute external programs.
dotpointer
15-May-2004 01:02
Win32 / PHP 4.3.6...
If you plan to start programs on the server that show message boxes (things that require OK from the server-side), or remain (like notepad.exe), and the exec-command seems to go into an deadly loop, then MAYBE your program has started, but you can't see it. Because the web server runs as an system process, and it isn't allowed to interact with the desktop.
To solve a part of the problem (to see the programs you execute), in the control panel in Windows, goto Administration->Services, right-click the server-service, goto Properties and on the second tab (login?) and check the box about allowing the service to interact with the desktop. Click OK. Restart the webserver, and MAKE SURE it is restarted for real (i.e. look in the task manager so the service goes _down_), otherwise the desktop-option won't take.
Next phase would be to stop PHP from waiting for the processes to complete (this is what makes PHP "loop"). I solved this by creating a small Delphi-application that took the path to the file I wanted to execute and executed it by the WinExec API, which just starts the childprogram but doesn't wait for it to complete = the program completes and the PHP.exe completes the script. Problem solved!
Delphi-snippet:
WinExec(PChar(<CMD>),SW_SHOW); // replace <CMD> with the program path.
vosechu at roman-fleuve dot com
26-Mar-2004 02:35
Quick chart that helped me immensely (Best (+) / worst (o) of each command) and when to use each (w).
| exec(string cmd, [array cmd_output, [int cmd_exit_status]])
+- Second (optional) argument holds an array containing the output line by line.
+- Third (optional) argument holds the exit status of the executed program.
w- When the output of a command is only important to the program.
| system(string cmd, [int cmd_exit_status])
+- Echos ascii output straight to browser (only stdout; stderr must be redirected by putting 2>&1 after the command to see errors).
+- Second (optional) argument holds the exit status of the executed program.
w- When the output of a command is important to the user.
The more I go over my notes the less I care for the last two functions.
Shell_exec() = exec() + implode() - exit codes.
And while neccessary to be able to pipe binary through php, most people will never use passthru
| passthru(string cmd, [int cmd_exit_status])
+- Echos binary output directly to browser window.
+- Second (optional) argument holds the exit status of the executed program.
w- When the output of a command is binary.
| shell_exec(string cmd) <-- minimal features to maintain sync with normal use of backticks.
+- Returns full output as a string instead of directly to the browser (only stdout; stderr must be redirected).
o- No way to check exit status (Should use system() with both stderr and stdout redirected to /dev/null to get the exit code).
ferchland at computer-kontor dot de
22-Jan-2004 04:24
I tried to fork a GUI-process on WinNT, Apache 2, PHP4.
I saw the new process (notepad.exe) in the Task-Managers process-list, but no Notepad-Window anywhere!
After activating the checkbox "Interactive with Desktop allowed" in Services->Apache everthing works with a simple command
exec("start c:\\winnt\\notepad.exe");
jeremy at ntb dot co dot nz
28-Sep-2003 04:18
If an error occurs in the code you're trying to exec(), it can be challenging to figure out what's going wrong, since php echoes back the stdout stream rather than the stderr stream where all the useful error reporting's done. The solution is to add the code "2>&1" to the end of your shell command, which redirects stderr to stdout, which you can then easily print using something like print `shellcommand 2>&1`.
dens at dodgeball dot com
18-Sep-2003 10:41
I was stuck for about an hour and a half last night trying to get Perl to pass back values to my PHP script after running an exec() command.
Since my Perl script was using STDOUT (after being passed command lines variables), I expected the variables used in my .pl script to be accessible in PHP, no questions asked.
Of course, this wasn't working and I finally figured it out with the help of a friend (Shawn = superstar): you need to echo the exec() command in order to get the values back into PHP.
Since I was returning multiple values, I added pipe delimiters in my .pl script and then used PHP to parse the string to retreive my data into different variables.
Check it out:
#hit the .pl script with the data
$mydata = exec("script.pl 'command line args' ");
exec("exit(0)");
#parse the value that comes back from the .pl script
list($strA, $strB) = split ('[|]', $mydata);
echo "valueA: " . $strA."<br>";
echo "valueB: " . $strB."<br>";
Woo-hoo!
/d
software at yvanrodrigues dot com
29-Jul-2003 09:55
MORE ON THE UNABLE TO FORK MESSAGES IN WINDOWS:
I would like to confirm that this issue relates to permissions on %SYSTEMROOT%\SYSTEM32. The user (usually the anonymous login) must have execute permissions on cmd.exe
This is unlike most other programming languages. For example, in C the spawn and exec functions do not try to open a shell, they create the new process directly. PHP creates the new process via cmd.exe (or command.com) much like the C system() function. This is good for those of you who are trying to run batch files but this is very ineffecient for running other .exe files.
I feel uneasy about lifting permissions in my system32 directory but you can get around this by copying cmd.exe to your PHP directory. Windows will look there first and if it is not there it will check the path. Note: I mean the directory where php.exe is, not your script directory.
I have confirmed this by running filemon.exe while trying to execute a script, and you can see it trying to start the cmd.exe process.
kristof_jebens at hotmail dot com
23-Jun-2003 09:23
For WIN2K Server users running Apache 1.3.22 who are unable to run an executable...
exec('c:\\WINNT\\system32\\cmd.exe /c START c:\\file.exe');
this is the only way it worked for me.
Hope that helps
david at mego dot com dot tw
02-Jun-2003 06:48
Okay here is my two cents for Windows users having "Unable to fork..." errors when executing "shell_exec" or "system" functions.
After numerous hours of testing, I realized that this error is a result of insufficient file permissions. You will need to locate c:\Windows\system32\cmd.exe and set the permission to at least Read & Executable for Internet Guest user accounts.
Then you should be able to run your script without a problem. If you still have a problem feel free to contact me by email.
leenoble at spammenot dot ntlworld dot com
09-May-2003 04:37
Even I typed in the full path to a command none of the shell functions worked at all.
exec("/usr/bin/mygoodcommand");
...just didn't produce results.
The command was world executable and ran fine from the shell. But after playing with the 2>&1 thing I established that "mygoodcommand" needed all of its commands to be path specific too. In my case I was attempting to dump a processed uploaded spreadsheet to a database with the command:
mysql --local-infile -u supportadmin --password='*******' personnel < /Users/leenoble/Sites/Websites/Support/data/updateexec.sql
In order for this to work I had to add:
/usr/local/mysql/bin/ to the mysql command to make it work. I hope this helps stop someone else from tearing their hair out in frustration.
mk at neon1 dot net
20-Apr-2003 04:17
If you want to execute background processes from PHP that should run indefinitely, be aware of the following nasty behavior (confirmed with PHP 4.3.1 under FreeBSD, but probably under other flavors of UNIX, too):
PHP internally calls setitimer(2) to set the profiling interval timer (ITIMER_PROF) to enforce execution time limits (max_execution_time and max_input_time). These timer values are passed down to all processes executed by PHP. This means that after such a process has consumed [max_execution_time] seconds of CPU time (not wallclock time!), the system will send it a SIGPROF (signal 27). Since most processes don't use this signal and as such don't call signal(3) to catch or ignore it, the default action is executed, which is to terminate the process.
So if you see background processes that were executed from PHP dying at seemingly random times, you may be experiencing this issue. The solution is simply to call set_time_limit(0) just before executing the process.
jpgiot at ifrance.com
26-Jan-2003 02:30
FOR WINDOWS USERS
i had a look to start command. it's really usefull in fact.
this is how i launch a specific Apache SSL server
<?php
$cmd = "start /D C:\OpenSA\Apache /B Apache.exe -D SSL";
exec($cmd,$output,$rv);
?>
/D specify the path where application will be launched (equivalent to cd to path)
/B launch application without a console window
so to know the exact parameters of start, you could use
<?php
exec("start /? > start.txt");
?>
and you will get the help of start in a file named 'start.txt' in the same place you run the script
for WIN 98 you may need to modify a little your command
exec("COMMAND.COM /C START program args >NUL");
(taken from another post)
jfl at eksperten dot dk
10-Jan-2003 06:01
I made my script work in the background like this:
function start_shell ($cmd) {
exec('nohup "'.$cmd.'" > /dev/null &');
}
qscripts at lycos dot nl
07-Jan-2003 01:45
Why not using the "start" utility, provided with every version of Windows to start processes in the background on Windows machines? For example :
exec("start song.mp3");
Which will cause the default handeling application for .MP3 file types to start playing the selected song..
NOtvdgeerSPAM at NOxs4allSPAM dot nl
03-Dec-2002 12:36
For users of PHP4 & Apache on Windows2000/XP:
If you're trying to execute a command-line application from PHP that has to show a (console) window on your desktop, make sure you enable the option to 'allow service to interact with desktop' in de service properties of Apache. (See your Windows services)
CAUTION: This can lead to security problems if your setting up a publicly available webserver!
k dot mitz dot NO_SPAM at att dot NO_SPAM dot net
15-Sep-2002 09:07
Newbie note:
The only syntax I found to work for the command portion of an an exec() call on a Win2K devel platform is:
$cmd = "\"path-to-exe\" args file-name";
where 'path-to-exe' has escaped double quotes, args are in the standard format, and 'file-name' has any backslashes escaped.
Example:
$cmd = "\"C:\program files\winzip\wzunzip.exe\" -c C:\\temp\\uploaded_file.zip";
exec($cmd,$output,$rv);
Note that the backslashes are escaped in the uploaded_file name, but not in the path to call the Winzip executable. Go figure!
kop at meme dot com
12-Aug-2002 09:52
AFICT, the standard Unix Apache configuration causes an rare problem when running a job in the background. The MaxRequestsPerChild directive causes the child to terminate after 1000 requests, any background processes associated with the child will die with the child unless they are started with the "nohup" command. Thus, the proper way to start a job in the background is to use:
exec('nohup my-command > /dev/null 2>&1 &')
ramirosuarez at fibertel dot com dot ar
13-Jul-2002 03:58
For Windows Users:
Keep in mind that a lot of UNABLE TO FORK Errors are the result of insufficient permissions.
CMD.EXE, TEMP Directory (or whatever you specified in php.ini), and all the directories that you use to upload o manipulate your files need to have Write privileges� usually user USER.
This will be useful for all the people who use GD Libraries or other programs that manipulate graphic images.
GCMXZPJPDJER at spammotel dot com
30-Jun-2002 07:41
to execute a script in background from php you don't need to use mikehup or other tools. just do:
`/usr/bin/php -q foobar.php >/dev/null 2>&1 &`;
mat
deschampsbest at noos dot fr
26-Jun-2002 08:05
I needed to know when a group of background tasks, which had been launched with a call to system, had terminated.
I could not find a function to call, so I created a little function.
It basically loops on the existance of a string in the results returned by the command ps.
All my commands, which run in background have the pid returned by posix_getpid in them.
I am able to launch many background task and effectively wait for them all to finish.
Before this, I would basically would sleep for N seconds.
I apologise if a well known or better method exist.
Thanks,
The New Bee
===============
===============
function wait_until_termination ($id, $duration){
$i = 0;
do {
$i += 1;
$cnt = `ps -auxww |
grep $id |
grep -v grep |
awk '{print $2}' |
grep -v $id|
wc -l` ;
if ($cnt > 0) {
sleep ($duration);
}
} while ($cnt != 0);
echo ("wait_until_termination (PID: $id, SEC: $duration) : LOOPS
:$i<BR>");
}
ronnyab at online dot no
22-Jun-2002 01:37
Instead of getting the whole package of load average and date, get only the days of uptime!
Use this code:
$uptime = exec("expr $(awk '{print $1}' < /proc/uptime | awk -F. '{print $1}' ) / 86400");
print("Uptime: $uptime days");
This will print "Uptime x days"!
info at businex dot de
17-Jun-2002 12:51
In handing over a parameter to such a background program, I succeeded with the following syntax:
exec("QUERY_STRING='campaign=$campaign'; export QUERY_STRING; php campaign_exec.php &");
rolland dot dudemaine at msg-software dot com
11-Apr-2002 12:45
In case you ever had to chain from php to another program (e.g. with a cgi php that only gives part of the output, or with php-gtk), here is a little C program that kills his parent (php, for instance), then launches a program given in argument.
chain.c :
#include <unistd.h>
int main(int argc, char**argv) {
/* kill the parent */
kill(getppid(), 15);
argv++;
/* then launch the new program */
return execvp(argv[0], argv);
}
(compile with gcc -O3 -o chain chain.c)
then in php, use
<?
exec('chain sh -c echo test');
?>
vi_pa at hotmail dot com
05-Apr-2002 12:17
For those who want to execute a .php script to run in the background, from a
.php web page...
exec("php script.php parameters 2>dev/null >&- <&- >/dev/null &");
Where...
- php is the path to your php script executer (php has to be specifically complied to be to do this)
- script.php is the script
- parameters are none or more parameters
- 2>dev/null redirects the stderr to a file
- <&- switches off the stdin
- >&- switches off the stdout
- >dev/null redirects all other output to the file dev/null
- & direct script to run in background
This is the only way I managed to get it working (Linux & Apache, php 4x enviroment) . What is also great is that the process is forked so even though a user may close the browser that initiated the exec(), the process will still run to completion. And the dev/null file can be turned into a log.
What I found odd is that the script I was execing would run fine in the bg when executed from the command line, but not from the browser until I closed the stdin and stdout.
alan_quill at hotmail dot com
22-Mar-2002 02:36
Simple way to encrypt a password using htpasswd.exe.
$anyname="/path/htpasswd -nb $username $password";
$somename=exec($anyname);
eg.For windows
$command="c:\apache\bin\htpasswd.exe -nb $username $password";
$encrypt=exec($command);
daniel dot hopp at godot dot de
01-Feb-2002 07:25
Re: session_write_close()
To launch a background process within a session, I recommend
to use a start-stop-daemon and ship parameters via ENV.
Example:
----------------------------------------
<?php
exec("/some/where/launch.sh 300");
?>
----------------------------------------
#!/bin/bash
# /some/where/launch.sh
T=$1
export T
DAEMON=/some/where/runme.pl
start-stop-daemon --start --quiet --background --exec $DAEMON
----------------------------------------
#!/usr/bin/perl
# /some/where/runme.pl
my $t = $ENV{'T'};
sleep($t);
----------------------------------------
edwin at bit dot nl
23-Jan-2002 11:47
If you are using sessions and want to start a background process, you might have the following problem:
The first time you call your script everything goes fine, but when you call it again and the process is STILL running, your script seems to "freeze" until you kill the process you started the first time.
You'll have to call session_write_close(); to solve this problem. It has something to do with the fact that only one script/process can operate at once on a session. (others will be lockedout until the script finishes)
I don't know why it somehow seems to be influenced by background processes, but I tried everything and this is the only solution. (i had a perl script that "daemonized" it's self like the example in the perl manuals)
Took me a long time to figure out, thanks [email protected]! :-)
lk1 at reglos dot de
25-Oct-2001 10:05
To keep a program running in the background on win98 the command
exec("COMMAND.COM /C START program args >NUL");
works fine for me.
naken at naken dot cc
15-Aug-2001 09:17
Anyone who still wants a copy of mikehup.c,
I rewrote it:
This program will help you run programs in the
background that are called with the php system()
function.
| |
pcntl_wtermsig
