Running sqlcmd from php - php

I have a pretty complicated bunch of sql calls that I have stored to a .sql file, that I can't call using sqlsrv_query because there are a bunch of GOs.
From the (windows) command line I can run the sql file using
"path\to\sqlcmd" -U name -P pass -S loc -i "path\to\stuff.sql"
I can also write system( [all that] ) in a php file that I run from the command line using php -f.
However, if I call the same system( [allthat] ) from a php file that I call using ajax on a website, I get no feedback, the sql just doesn't run. I've checked sqlcmd, and it has permissions to allow all users to execute.
Any ideas?

Permissions issue. If you're running it from the command line, it's running under YOUR permissions. When you invoke it via a webserver, it's running with the webserver's permisisons. The webserver will need execute rights (and permission to REACH the sqlcmd) as well as read rights on the .sql file (and permission to reach it).

For that, you may use the shell_exec.

Related

Why cannot PHP execute a command from web browser?

This is really simple but I cannot get it to work at all. Spent many hours and I've always give up. I created php script called copy.php and it should call a python script called copy.py.
I want to execute a command line like this
<?php exec('/var/www/html/copy.py'); ?>
Really simple.
Why cannot I get the python script executed from php exec()? The function inside python script is to get a copy of error_log from a different directory (outside of Apache) into html directory.
If I run that from a terminal
> php copy.php
It did execute the function and made a copy. Why is that the web browser isn't doing it?
Let me simplify this:
why cannot exec("cp /var/log/httpd/error_log /var/www/html/path/to/php/script") work?
it works fine if I type it in terminal but not when run in a browser.
As others have alluded to, the difference is probably permissions. When you run a command from the command line, you're generally not the same users as your apache script is running as.
Put another way, if from the command line you type whoami, you'll probably get whatever name your user account is.
The echo exec('whoami'); from within php shows who the script is running as, which is Apache.
So, whatever command you're trying to run from your web server isn't available to run as the Apache user. You mentioned you've been able to have exec("python /usr/diskpurge/script.py") work, but not to have exec('/var/www/html/copy.py') doesn't. This is due to in one instance you're running python, in the other you're trying to execute your copy.py script. If copy.py doesn't have execute permissions for the Apache user, you're not going to be able to run it from the browser.
Perhaps different settings apply for the Apache environment versus the command line.
Use error_reporting(E_ALL); and ini_set('display_errors', true) to see what errosr may come up.
It is possible that the Apache environment is prohibited from using exec or the fact that Apache runs under a different user that does not have execute rights on the python script.
sounds like a permission error. Check if your server is running with sufficient rights.
echo exec('whoami');
Set your error reporting to report all:
ini_set('display_errors', true);
error_reporting(E_ALL);
and check for errors..
If your whoami returns a user which is not a member of the SU family (linux) or administration (windows) then resite your permissions..
Linux:
Assign the user returned by whoami correct permissions to run python scripts.. Do not allow the resulted username to run as root with total administration powers.. This is a big no no
The only reason its not working is because you didn't set the write permissions!
Do:
sudo nano /etc/sudoers
And then put the following:
www-data ALL=(root) NOPASSWD:ALL

Integrating php in shell scripts for a cronjob?

I would like to execute a cronjob for a routine task every X hours. The cronjob basically executes a shell script which in turn uses a WGET command to download files from a remote server. However, before I run this shell script I want the cronjob to execute a php script which will check whether the update's available (there's no point in wasting BW and downloading the same file over and over again) and if it is, it should pass on the update URL to the shell script which in turn uses the WGET command.
The cronjobs are set from the hosts Admin Panel. There is no other way around it. Being a shared hosting service, I am not allowed access to other functions on PHP which might do the task for me either.
Is this possible? I am Linux illiterate. I have installed a few RPM's on Fedora but that's about it. Please bear with me. Thanks!
Just pass --timestamping to your wget command.
Alternatively if you are more familiar with PHP's ways you can check this question for a usable method.
Use a curl HEAD request to get the file's headers and parse out the Last-Modified: header.
To use a php script as a regular command line executable use this as a starting point:
#!/bin/env php
<?php
echo "Hello World\n";
Save the file without the .php and tuck it somewhere that your server won't serve it.
Next, set the executable bit so that you can execute the script like a regular program
(u+x in the following command means grant the [u]ser e[x]ecute privileges for helloworld, and chmod is the command that unix variants use to set file permissions)
Omit the $ in the following sequence, as it represents the command prompt
$ chmod u+x helloworld
now you can execute your commandline script by calling it in the bash prompt:
$ ls
helloworld
$ ./helloworld
Hello World
$
From here you can get the full path of the executable script:
$ readlink -f helloworld
/home/SPI/helloworld
And now you can install the cronjob using the path to your executable script.

php to call a shell script

purpose: use php to input commands directly into the minecraft server console
Im trying to use a php script (run from browser) to exec() a shell script. when i run the php from a terminal it works! But in the browser, nothing happens.
exec('sudo -u root sh /home/minecraft/whitelist-reload.sh', $out, $ret_val);
When running from terminal, i get a "array 0" but the browser gives me a "array 1"
what is the issue?
and once i run the shell, shouldn't everything after that work as if you were on a terminal?(does it matter what is inside of shell script?)
the shell has all rx permissions and is in the sudoers file as
www-data ALL = NOPASSWD: /home/minecraft/whitelist-reload.sh
The problem is, that you run the script on a terminal as a user that probably has the sudo rights, whereas the apache/webserver user doesn't, so the $ret_val (which is actually just a status code) is set to 1 (means error).
try var_dump($out); in both cases to see the results of your exec call. To do this kind of thing from the browser, you might want to look into proc_open and family, or have a script that is chmod'ed to 777, so the apache user can run it, too. Let that script then call the actual shell script and return it's output back. This is, however very dangerous, and should only be used for testing environments on your own machine. Never do this in production environments!
I have posted a couple of questions here, too that might prove informative:
interaction over ssh
opening a second shell, and load profile variables AND call another script
Turns out... after inputting www-data into the sudoers file, all i needed to do was take of the "-u root" after it

PHP exec() not working properly

I am having difficulty with the PHP exec() function. It seems to not be calling certain functions. For instance, the code echo exec('ls'); produces no output whatsoever (it should, there are files in the directory). That main reason this is a problem for me is that I'm trying execute a .jar from a PHP exec() call.
As far as I know I'm calling the java program properly, but I'm not getting any of the output. The .jar can be executed from the command line on the server. (For the record, it's an apache server).
My php for the .jar execute looks like this:
$output = array();
exec('java -jar testJava.jar', $output);
print_r($output);
All I get for output from this exec() call is Array().
I have had success with exec() executing 'whoami' and 'pwd'. I can't figure out why some functions are working and some aren't. I'm not the most experienced person with PHP either, so I'm not too sure how to diagnose the issue. Any and all help would be appreciated.
The reason why you are not able to execute ls is because of permissions.
If you are running the web server as user A , then you can only ls only those directories which have permissions for user A.
You can either change the permission of the directory or you can change the user under which the server is running by changing the httpd.conf file(i am assuming that you are using apache).
If you are changing the permissions of the directory, then make sure that you change permissions of parent directories also.
To change the web server user, follow following steps:
Open the following file:
vi /etc/httpd/conf/httpd.conf
Search for
User apache
Group apache
Change the user and group name. After changing the user and group, restart the server using following command.
/sbin/service httpd restart
Then you will be able to execute all commands which can be run by that user.
EDIT:
The 'User' should be a non-root user in httpd.conf. Apache by default doesnot serve pages when run as root. You have to set user as a non-root user or else you will get error.
If you want to force apache to run as root, then you have to set a environment variable as below:
env CFLAGS=-DBIG_SECURITY_HOLE
Then you have to rebuild apache before you can run it as root.
I have found the issue - SELinux was blocking PHP from accessing certain functions. Putting SELinux into permissive mode has fixed the issues (although, I'd rather not have to leave SELinux in permissive mode; I'd rather find a way of allowing certain functions if I can).
I have a solution:
command runs from console, but not from php via exec/system/passthru.
The issue is the path to command. It works with the absolute path to command
So that:
wkhtmltopdf "htm1Eufn7.htm" "pdfIZrNcb.pdf"
becomes:
/usr/local/bin/wkhtmltopdf "htm1Eufn7.htm" "pdfIZrNcb.pdf"
And now, it's works from php via exec
Where command binary you can see via whereis wkhtmltopdf
Tore my hair out trying to work out why PHP exec works from command line but not from Apache. At the end, I found the following permissions:
***getsebool -a | grep httpd*** ---->
**httpd_setrlimit --> off
httpd_ssi_exec --> off
httpd_sys_script_anon_write --> off**
USE: setsebool -P httpd_ssi_exec 1
SEE: https://linux.die.net/man/8/httpd_selinux
Your problem is not an execution issue but the syntax of the exec command. The second argument is always returned as an array and contains a single line of the output in each index. The return value of the exec function will contain the final line of the commands output. To show the output you can use:
foreach($output as $line) echo "$line\n";
See http://php.net/manual/en/function.exec.php for details. You can also get the command's exit value with a third argument.

backup mysql database by calling a batch file through php

I failed with the mysqldump method earlier. Now I'm trying to just call the batch file which will call the mysqldump.
The php file which calls the batch file, looks something like this:
<?php
shell_exec('c:\\abc.bat');
?>
And the batch file, which when I execute directly yields the 7kb sql file that I'm expecting:
mysqldump --opt -u root -ppassword onstor > c:\onstordb.sql
But when I use php to execute it, I get a 0 Kb file, I wonder why. I tried both shell_exec and exec. Is there something wrong with the parameters?
http://www.php.net/manual/en/function.exec.php#85930
It reads:
I was having trouble using the PHP
exec command to execute any batch
file. Executing other commands
(i.e., "dir") works fine). But if I
executed a batch file, I receieved no
output from the exec command.
The server setup I have consists of
Windows Server 2003 server running
IIS6 and PHP 5.2.3. On this server, I
have:
Granted execute permissions to the Internet User on
c:\windows\system32\cmd.exe.
Granted Everyone->Full Control to the directory in which the batch file
is written.
Granted Everyone->Full Control on the entire c:\cygwin\bin directory
and its contents.
Granted the Internet User "log on as batch" permissions.
Specified the full path to each file being executed.
Tested these scripts running from the command line on the server and
they work just fine.
Ensured that %systemroot%\system32 is in the
system path.
It turns out that even with all of the
above in place on the server, I had to
specify the full path to cmd.exe in
the exec call.
When I used the call:
$output = exec("c:\\windows\\system32\\cmd.exe /c $batchFileToRun");
then everything worked fine. In my
situation, $batchFileToRun was the
actual system path to the batch file
(i.e., the result of a call to
realpath()).

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