calling Windows program from PHP file (through command-prompt) - php

I have tried calling a windows program several ways and I have gotten the same result each time.
The program opens up on my machine (without a GUI) but never closes each means that the browser is forever loading.
Though when executing the query string manually through the command line prompt the program closes. Not only that, but the program doesn't actually execute
(it is just launched i.e. there aren't any results).
I just want to know the proper way of starting a program with switches through PHP.
Here is the query string that works (closes the program after executing):
"C:\Program Files (x86)\Softinterface, Inc\Convert PowerPoint\ConvertPPT.exe" /S
"C:\Users\Farzad\Desktop\upload\test.ppt" /T "C:\Users\Farzad\Desktop\upload\test.png" /C 18

If the program never closes, then PHP can't return a value from exec(). The program must close. Chances are there is a problem accessing your files on your desktop in this manner. It will be executed with whatever permissions the webserver has defined.
http://php.net/manual/en/function.exec.php
You might consider the advanced functionality of proc_open(). It will give you access to all the necessary pipes, but I don't think that will help you in this situation.

If the target directory on your Windows machine is C:\Program Files (x86)\Softinterface, Inc\Convert PowerPoint\ConvertPPT.exe, you need to double-quote the directories that have space character within them.
To translate it into php terms, it should be like this:
$directory = 'C:\"Program Files (x86)"\"Softinterface, Inc"\"Convert PowerPoint"\ConvertPPT.exe';
$command = $directory . ' enter your arguments here';
exec($command, $output, $return_var);
// if $return_var == 0, you hit the jackpot.

The physical directory where your Windows desktop is stored belongs to your user profile folder. That means that other users (including the one Apache runs as, which is typical "Local System") won't have the appropriate permissions to read and write files on it. While you can adjust your Apache set-up to make it run with your own user, Farzad, it's more common to put web applications in an entirely different directory tree. It may happen that ConvertPPT.exe just stalls because it's trying to write a file at a location where it's not allowed. I suggest you create a top folder directory and make sure it's world-writeable (once finished, you can tighten these permissions if you like).
Once you discard (or confirm) that the issue is caused by lack of appropriate credentials, make sure you are escaping your command and arguments properly. See this link:
http://es2.php.net/manual/en/function.exec.php#101579
One more thing you can try is to close PHP sessions before issuing the call to exec():
http://es2.php.net/manual/en/function.exec.php#99781

You have probably run into this bug: http://bugs.php.net/bug.php?id=44994
which has been bothering me for ages, even today, on PHP 5.3.5.
It seems like there is some kind of deadlock between the error output of the program and the apache error log file handle into which the program is redirected to write its stderr output, making the program be stuck for ever until the apache processes are killed.
Also, when using passthru, or system, or the backtick operator, there's an intermediary "cmd.exe" process that is used to run the program in an invisible console, and I have seen this cmd process getting stuck without even running the program.
I don't really have a solution as of now, and it seems the bug, even though reproduced by many people, hasn't been resolved.

Related

why is my "at job" not executing my php script when created through a php webpage?

$output = shell_exec('echo "php '.$realFile.'" | at '.$targTime.' '.$targDate.' 2>&1');
print $output;
Can someone please help me figure out why the above line isn't doing what it's supposed to be doing? The idea is for it to create an 'at' job that will execute a php script. If I switch to the user apache(which will ideally control the at function when the php file is complete) I can run
echo "php $realFile.php" | at 00:00 05/30/17
and it'll do EXACTLY what I want. The problem is in the above snippet from my php file it will not create the at job correctly. when I do a at -c job# on both of them the job made from my file is about a 3rd the length missing the User info and everything. It basically starts at PATH= and goes down. Doesn't include HOSTNAME=, SHELL=, SSH_CLIENT=, SSH_TTY=, USER=. I assume it needs most of this info to run correctly. The end output (below)is always the same though it just doesn't have any of the top part for some reason. Let me know if you need more info. I didn't want to paste all of my code here as it contains job specific information.
${SHELL:-/bin/sh} << 'marcinDELIMITER0e4bb3e8'
php "$realFile".php
marcinDELIMITER0e4bb3e8
It doesn't seem to be a permission issue because I can su to apache and run the exact command needed. The folder the files are located in are also owned by apache. I've also resulted to giving each file I try to run 777 or 755 permissions through chmod so I don't think that's the issue.
I figured out a coupe ways around it a while back. The way I'm using right now is an ssh2 connect to my own server as root and creating it that way. No compromise as you have to enter the password manually each time. Really bad work around. The main issue is that apache doesn't have the correct permissions to do everything needed for the AT job so someone figuring that out would be awesome. Another option I found on a random webpage would be to use sudo through the php script, but basically the same minus having to reconnect to your own server. Any other options would be appreciated.
Reading the manual and logs would be a good place to start. In particular:
The value of the SHELL environment variable at the time of at invocation will determine which shell is used to execute the at job commands. If SHELL is unset when at is invoked, the user’s login shell will be used; otherwise, if SHELL is set when at is invoked, it must contain the path of a shell interpreter executable that will be used to run the commands at the specified time.
Other things to check are that the user is included in at.allow, SELinux is disabled and the webserver is not running chrrot.

How to catch the result of a background PHP script launched from inside PHP?

I've got some PHP code that I want to run as a background process. That code checks a database to see if it should do anything, and either does it or sleeps for awhile before checking again. When it does something, it prints some stuff to stdout, so, when I run the code from the command line, I typically redirect the output of the PHP process to a file in the obvious way: php code.php > code.log &.
The code itself works fine when it's run from the shell; I'm now trying to get it to run when launched from a web process -- I have a page that determines if the PHP process is running, and lets me start or stop it, depending. I can get the process started through something like:
$the_command = "/bin/php code.php > /tmp/code.out &";
$the_result = exec($the_command, $output, $retval);
but (and here's the problem!) the output file-- /tmp/code.out -- isn't getting created. I've tried all the variants of exec, shell_exec, and system, and none of them will create the file. (For now, I'm putting the file into /tmp to avoid ownership/permission problems, btw.) Am I missing something? Will redirection just not work in this case?
Seems like permission issues. One way to resolve this would be to:
rename your echo($data) statements to a function like fecho($data)
create a function fecho() like so
.
function fecho($data)
{
$fp = fopen('/tmp/code.out', 'a+');
fwrite($fp, $data);
fclose($fp);
}
Blurgh. After a day's hacking, this issue is finally resolved:
The scheme I originally proposed (exec of a statement with
redirection) works fine...
...EXCEPT it refuses to work in /tmp. I
created another directory outside of the server's webspace and opened
it up to apache, and everything works.
Why this is, I have no idea. But a few notes for future visitors:
I'm running a quite vanilla Fedora 17, Apache 2.2.23, and PHP 5.4.13.
There's nothing unusual about my /tmp configuration, as far as I know (translation: I've never modified whatever got set up with the basic OS installation).
My /tmp has a large number of directories of the form /tmp/systemd-private-Pf0qG9/, where the latter part is a different set of random characters. I found a few obsolete versions of my log files in a couple of those directories. I presume that this is some sort of Fedora-ism file system juju that I will confess to not understanding, and that these are orphaned files left over from some of my process hacking/killing.
exec(), shell_exec(), system(), and passthru() all seemed to work, once I got over the hump.
Bottom line: What should have worked does in fact work, as long as you do it in the right place. I will now excuse myself to take care of a large bottle of wine that has my name on it, and think about how my day might otherwise have been spent...

Calling Ruby script with PHP

Fair warning; I don't even really know Ruby. I'm just hacking together some scripts that I was given and hoping they'll work together.
Background
I'm using Ruby to automate several tasks as an svn administrator, and one of the tasks that I'm trying to effect is making a web-form that will automate the creation of a repository.
The script I'm running is about 100-200 lines total, including the includes and things like that. I'm sure there will be other problems with the code, but presently, it's running into one problem.
The Ruby script itself works. My problem is that it doesn't work when I try to call it from a PHP script in a different directory.
The directory structure is like this:
Home
.www-docs
makeRepo.php
svn
createNewRepo.php
migrateOne.php // This has yet to cause a problem
RepoUtils.rb // Not currently causing a problem
Problem
The exact problem that I'm running into is that the Ruby script stops executing (and doesn't print an error message that I can echo in the PHP at a particular point in the code.
I'm calling the script as follows:
chdir("../svn");
echo exec("ruby createNewRepo.rb $name1 $name2 $num")
So, it's definitely calling the script. I put print points throughout the script, so I know it stops around here:
print "Point 1"
acl = File.new(##aclfile, "a")
print "Point 2"
##aclfile is an absolute path, not relative, so I don't think that alone is the problem.
The above code will end up printing Point 1 (and nothing that comes after that, either).
What am I doing wrong?
Thanks!
If it works when you run it by hand, but not through the PHP script, I'm thinking you've got a permissions problem. If the user that the web process is running as doesn't have access to the absolute path (or the path doesn't exist), you'll hit an error:
$ irb
1.8.7 :001 > File.new("/this/doesn't/exist", "a")
Errno::ENOENT: No such file or directory - /this/doesn't/exist
from (irb):1:in `initialize'
from (irb):1:in `new'
from (irb):1
1.8.7 :002 > File.new("/etc/passwd", "a")
Errno::EACCES: Permission denied - /etc/passwd
from (irb):2:in `initialize'
from (irb):2:in `new'
from (irb):2
1.8.7 :003 >
Check your permissions on the target directory and determine whether the web user has access to it. For security reasons, I won't tell you to change the web user's permissions or to change permissions on the target directory. You'll have to make that call yourself.

How can I troubleshoot why my PHP script won't work in cron when it does from the command line?

I've got a script that calls two functions, A and B, from the same class. A creates an Amazon virtual server and B destroys one, both via shell_exec()'s of Amazon's command line tools. The script, doActions.php, pulls actions from a queue. If the action is "create" it creates an instance; when the action is "destroy" it kills one.
The script works fine to execute both A and B when I execute it from the command line: php script.php.
When I put it on a cron, it runs but only successfully runs the B function. It deletes destroys instances but won't create them.
The point of failure is clearly function B. It chokes at the first and most important shell_exec, returning and echoing nothing.
echo $string = shell_exec('/home/user/public_html/domain.com/private/ec2-api-tools/bin/ec2-run-instances ami-23b6534a -k gsg-keypair -z us-east-1a');
Unless you know something specific about the way Amazon's command line tools work, please suggest to me reasons why a shell_exec might work in one case and not the other.
Another shell_exec in the same place behaves as expected:
echo $string = shell_exec ('echo overflow');
My guess is that it has to do something with permissions. But when I have it run shell_exec('whoami') it return "root," and when I su and run the command it works fine. I'm having a hard time thinking of creative ways to troubleshoot why my PHP script won't work in cron when it does from the command line. Can you suggest some?
When something runs from the command line but refuses to do so within cron, it's often an environment issue (path or some other environment variable that's needed by the code you're running).
For a start you should modify the script to output the current environment (shell_exec('env')?) at the very top and examine the output from the command line and cron.
Hopefully, there will be something obvious such as AMAZON_EC2_VITAL_VAR but, if not, you should move the cron environment towards your command line one, one variable at a time, until it starts working.
A quick test to ascertain this. From your command line, do:
env >/tmp/pax_env.sh
Then run your PHP script from a shell script which first executes:
. /tmp/pax_env.sh
so that the environments are identical.
And keep in mind that su on its own doesn't give you the same environment as you'd get from logging in directly as a specific user (su - does, I think). You may want to check the behaviour for when you log in as root directly.
Re your comment:
Yes, I do believe you've got it. I'm likely going to mark your answer as correct but need you to suffer through a few addendums about your clever solution. First of all, what's the best way to execute the pax_env.sh script? Does shell_exec() work?
Never let it be said I didn't work for my money :-) No. The shell_exec will almost certainly be running a sub-shell so the variables would be set in that sub-shell but would not affect the PHP parent process.
My advice, if you wanted all those variables set, would be to create a shell-script consisting of all the commands in /tmp/pax_env.sh (probably prefixing each with export) followed by the command you currently have running in cron, something along the lines of:
export PATH=.:/usr/bin
export PS1=Urk:
export PS2=MoreUrk:
/home/user/pax/scriptB.php
Then run that script from cron rather than /home/user/pax/scriptB.php directly. That will ensure the environment is set up before your PHP code is called.
Astute readers will have noticed the phrase "if you wanted all those variables set" above. I don't personally think it's a good idea to dump all your command line variables into the shell script for the cron job. I'd prefer to actually find out which ones are needed and only include those. That lessens the pollution your cron job has to run under. For example, it's unlikely that the PS1/PS2 prompt variables will be required for your PHP script.
If it works, you can set all the environment variables - I just prefer the absolute minimum so I don't have to worry too much when things change.
A way of finding out what's needed is to comment out one export at a time until your script breaks again. Then you know that variable is needed. Once it works with the maximum amount of export statements commented out, you can just delete those commented export statements altogether and what remains, however improbable, must be okay (with apologies to Sir Arthur Conan Doyle).

Why has my PHP system() command stopped returning output to my scripts ... i used to work!

I have a PHP script that calls a .bat file using system(). The output is written to the screen and I derive some values from parsing this output. This is running on windows 2003 IIS server. PHP v5.2.0
Specifically I am using this script to launch an Amazon EC2 instance and assign an IP address to it. It has worked great for me so far but recently the problem started.
Here is the code
$resultBatTemp = system("cmd /C C:\Inetpub\ec2\my_batch_file_to_launch_instance.bat");
$resultBat = (string)$resultBatTemp;
$instanceId = substr($resultBat, 9, 10);
...
Once I have this instace Id I can run another batch file that calls associates an ip address with this instance. It would appear that the instance does get launched but I never get the output on the screen.
For some reason this has all stopped working, the page freezes and never refreshes. I also need to completely exit safari or mozilla otherwise all pages from the website fail to load. Only when I relaunch the browser can i view the website again. I've connected to the webserver that hosts these scripts and checked PHP error log but nothing shows there. I've opened a DOS prompt and entered the code from the bat file that way and it connects to amazon and launches the instance fine. Ive isolated this bit of code and removed the system command and the rest of the script runs fine, so it appears that the hold up is with outputting the results of the bat file.
Recently I have purchased a new domain name for the site so this script is running from this domain. Might this cause the problem?
thanks
------------------------------------------------UPDATE-----------------------------------------------
Well hope this helps someone, I didnt find out what was wrong but created a new PHP file with a simple system command that called a .bat file, and a non-existent .bat file expecting to get an error back but nothing - just the usual hang for ages. So I restarted IIS and this fixed the problem. Dont know what was wrong but that did the trick.
Maybe first check what the system() call returns. According to documentation it will return FALSE in case of failure. Also, including your my_batch_file_to_launch_instance.bat in the question might help in solving it.
Try using the passthru function
Also make sure that all your commands are safe use escapeshellarg() or escapeshellcmd() to ensure that users cannot trick the system into executing arbitrary commands.

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