mysqldump not working at all :( - php

I have this code :
function export()
{
$exp = system("mysqldump -uguku -pjustbe repadmin > back-up.sql");
if($exp) {echo 'ok';}
else { echo 'err';}
}
But it doesn't work, all it does, is to create the "back-up.sql" file, but it's blank.
And I get the "err" message.

Try using the full path to mysqldump...
$exp = system("/full/path/mysqldump -uroot -p repadmin > back-up.sql");
which mysqldump will tell you what the path should be.

Here you have a command that's not running properly. Best thing to do is to capture stderr (where error messages go) and see what the output is. Another thing to note is that environment variables will be different - such as the PATH (refered to by #Joshua_Martell above).
Use this command to capture stderr and see what error messages are being produced:
/usr/bin/mysqldump -uguku -pjustbe repadmin > back-up.sql 2> mysqldump.err
This also uses a full path to mysqldump (use the right path). You also probably should add a path to back-up.sql and, in this case, to mysqldump.err - don't assume that PHP will run in the directory you want as it could change.

Related

shell_exec() always returning an empty string

I am trying to create a server within my Android phone. I am unable to execute any shell script from my PHP code.
Here's the code:
//index.php
<?php
$output=shell_exec("sdcard/htdocs/myscript.sh 2>&1");
if(!$output){
echo "Failed";
}else{
echo $output;
}
?>
//myscript.sh
cd sdcard/htdocs/images
ls -t1 | head -n 1
The script works fine within terminal emulator. I also tried changing permissions of the script file but that didn't work. I don't know if it requires superuser permissions to execute shell scripts within PHP code.
The whole code is used to return the filename of the last file created in the images directory.
Need suggestions to make this code work.Is there any other way to perform the required job?
Make sure what you have run
chmod a+x sdcard/htdocs/myscript.sh
on your file.
Also $output is not a boolean.
Your code looks fine. Superuser permission is not necessary for script execution. You should turn on PHP error output or check the PHP error log file. I bet you find the reason there. If not, recheck the directory, and file permissions:
./index.php
./sdcard/htdocs/myscript.sh
./sdcard/htdocs/images
sdcard and sdcard/htdocs require executable persmissions. sdcard/htdocs/images requires executable and read permission (ls in myscript.sh), and so does sdcard/htdocs/myscript.sh. But I guess it's something else because permission errors should be displayed (2>&1).
Edit
You can find the last modified file with PHP, no need to run another process. Take one of these two:
$images = glob('sdcard/htdocs/images/*');
$images = array_combine(array_map('filemtime', $images), $images);
asort($images);
echo $lastModifiedImage = end($images);
Or with some fewer array operations:
$images = glob('sdcard/htdocs/images/*');
array_reduce($images, function($previous, $element) use (&$found) {
$mtime = filemtime($element);
$found = $previous < $mtime ? $found : $element;
return $previous < $mtime ? $mtime : $previous;
}, 0);
echo $found;
sdcard and sdcard/htdocs require executable persmissions. sdcard/htdocs/images requires executable and read permission (ls in myscript.sh), and so does sdcard/htdocs/myscript.sh. But I guess it's something else because permission errors should be displayed (2>&1).
Probably FAT !

Finding correct of PHP binary - exec()

I'm trying to execute a separate PHP script from within a PHP page. After some research, I found that it is possible using the exec() function.
I also referenced this SO solution to find the path of the php binary. So my full command looks like this:
$file_path = '192.168.1.13:8080/doSomething.php';
$cmd = PHP_BINDIR.'/php '.$file_path; // PHP_BINDIR prints /usr/local/bin
exec($cmd, $op, $er);
echo $er; // prints 127 which turns out to be invalid path/typo
doSomething.php
echo "Hi there!";
I know $file_path is a correct path because if I open its value; i.e. 192.168.1.13:8080/doSomething.php, I do get "Hi there!" printed out. This makes me assume that PHP_BINDIR.'/php' is wrong.
Should I be trying to get the path of the php binary in some other way?
The file you are requesting is accessible via a web server, not as a local PHP script. Thus you can get the result of the script simply by
$output = file_get_contents($file_path);
If you however for some reason really have to exec the file, then you must provide a full path to that file in your server directory structure instead of server URL:
$file_path = '/full/path/to/doSomething.php';
$cmd = PHP_BINDIR.'/php '.$file_path;
exec($cmd, $op, $er);

mysqldump common install locations for mac/linux

I am trying to know all the common locations for mysqldump. The list I have come up with is as follows:
'/usr/bin/mysqldump', //Linux
'/usr/local/mysql/bin/mysqldump', //Mac OS X
'/usr/local/bin/mysqldump', //Linux
'/usr/mysql/bin/mysqldump'; //Linux
Often mysqldump isn't in the path, so I am trying to have all the locations to look in. (I am running this from a php script)
Are there any that I am missing?
I was unable to find any other paths apart from the ones you have given in your question. However, one thing that does come in my mind is that mysqldump should, in most cases, be in the same directory as the mysql binary. Now, the mysql command will be in the path, in most cases, as well.
And, therefore, you can combine the two logics to have the location of the mysqldump binary, in most cases, like this:
function detect_mysqldump_location() {
// 1st: use mysqldump location from `which` command.
$mysqldump = `which mysqldump`;
if (is_executable($mysqldump)) return $mysqldump;
// 2nd: try to detect the path using `which` for `mysql` command.
$mysqldump = dirname(`which mysql`) . "/mysqldump";
if (is_executable($mysqldump)) return $mysqldump;
// 3rd: detect the path from the available paths.
// you can add additional paths you come across, in future, here.
$available = array(
'/usr/bin/mysqldump', // Linux
'/usr/local/mysql/bin/mysqldump', //Mac OS X
'/usr/local/bin/mysqldump', //Linux
'/usr/mysql/bin/mysqldump' //Linux
);
foreach($available as $apath) {
if (is_executable($apath)) return $apath;
}
// 4th: auto detection has failed!
// lets, throw an exception, and ask the user to provide the path instead, manually.
$message = "Path to \"mysqldump\" binary could not be detected!\n"
$message .= "Please, specify it inside the configuration file provided!"
throw new RuntimeException($message);
}
Now, you can use the above function for your purposes. And, provide a way for the user to provide the explicit path to mysqldump binary manually, if the above function throws an error. Should work for your use cases :)

passing php variable to bash script that uses shflags

I am trying to make a PHP program triggered by a web submit tell a bash script to run with a single command line parameter. I am using the shflags command line parser for bash.
The pertinent part of the PHP script is as follows:
// generate unique filename
$destinationFolder = Mage::getBaseDir('media') . DS . 'webforms' . DS . 'xml';
$filename = $destinationFolder . DS . $result->getId().'.xml';
// create folder
if (!(#is_dir($destinationFolder) || #mkdir($destinationFolder, 0777, true))) {
throw new Exception("Unable to create directory '{$destinationFolder}'.");
}
// export to file
$xmlObject->getNode()->asNiceXml($filename);
// define parameters to pass
exec ( '/opt/bitnami/apache2/htdocs/sfb/scripts/xform.sh --xmlfile'.' '.$filename);
}
}
?>
The bash script (xform.sh) (just a test script) is as follows.
#!/bin/bash
. ./shflags
echo "foo" >> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/$$".txt"
echo "foo" >> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/foo.txt
DEFINE_string 'xmlfilename' 'test' 'filename of current x.xml file from webforms' 'Z'
FLAGS "$#" || exit 1
eval set -- "${FLAGS_argv}"
echo "xml file was" ${FLAGS_xmlfilename} >> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/foo.txt
The bash script works correctly from the command line, i.e.
$xform.sh --xmlfilename 1.xml
writes "xml file was 1.xml" to the foo.txt file.
When the PHP script is triggered from the web, the first part works correctly, i.e. it writes "foo" to the two target files, foo.txt and $$.txt. However, the xmlfilename variable is not coming along, and I really need that file name to be passed to the command line! (Note I should not need to use escapeshellarg because the file name is generated by my PHP program, not by user input.)
I have checked all the file permissions I can think of. xform.sh and shflags are both members of the www-data (Apache) group, owned by Apache, and a+x.
My suspicions are that the problem is related either to a) my PHP exec syntax or b) file permissions. Everything works as intended except the bit after xform.sh in this line!
exec ( '/opt/bitnami/apache2/htdocs/sfb/scripts/xform.sh --xmlfile'.' '.$filename);
UPDATE:
I've narrowed the problem some more by isolating the problem with some test code. With:
$script="echo";
$xmlfilename="$filename";
$target=">> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/foo.txt";
exec ("$script $xmlfilename $target");
...
PHP correctly writes the $filename to foo.txt, so $script works when value is "echo" and $filename works too.
When I set $script to a different simple form of the xform script that (only) writes the data to the file, that also works correctly.
So the problem is specifically with something that happen when PHP tries to write the $filename as a command line variable. Does a script run by Apache need more permissions than usual if it includes a command line variable?
Sigh.
In your exec() call you have the flag as --xmlfile but you are calling it from the command line as --xmlfilename

PHP, problem with exec...how do I make sure the execution is working?

I am uploading a video, which is supposed to generate three screenshot thumbnails. I have the same upload code running in both admin and front-end, but for some odd reason the thumb is only being generated when I upload from front end, and not from backend...
My directory structure
root/convert.php (this is the file running through exec call)
(the following two files are the upload files running in user-end and admin-end respectively)
root/upload.php
root/siteadmin/modules/videos/edit.php
I believe convert.php is not being run from admin-side for some reason. The command is something like:
$cmd = $cgi . $config['phppath']. ' ' .$config['BASE_DIR']. '/convert.php ' .$vdoname. ' ' .$vid. ' ' .$ff;echo $cmd;die;
exec($cmd. '>/dev/null &');
And echoing out the exec $cmd, I get this:
/usr/bin/php /home/testsite/public_html/dev/convert.php 1272.mp4 1272 /home/testsite/public_html/dev/video/1272.mp4
How do I make sure convert.php is being run?
EDIT: OK, now I am sure it is not being executed from admin-side, any ideas why?
http://php.net/manual/en/function.exec.php
"return_var" - If the return_var argument is present along with the output argument, then the return status of the executed command will be written to this variable.
Another way to determine if exec actually runs the convert.php file, add some debugging info in convert.php (e.g. write something to a file when the covert.php script starts).
Just an Idea
you could print "TRUE" in the convert script when it runs successfully.
don't add >/dev/null &
check the return value of exec
$value = exec($cmd);
if($value == 'TRUE')
// did run sucessfully
}
chmod 755 convet.php
you also make sure the first line of convert.php is:
#!/usr/bin/php
check the full path of php cli executable.
Also make sure convert.php las unix line ending ("\n")

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