File permissions on files created by PHP [duplicate] - php

I have a folder above the webroot that is used to temporarily store user files generated by a php web application. The files may, for example, be PDF's that are going to be attached to emails.
The folder permissions are set to rwxr-xr-x (0755). When executing a procedure from the web application, the files get written to this folder without any issues.
I have now also set up a cron job that calls the php script to execute that exact same procedure as above. However, the PDF cannot be saved into the above folder due to failed permissions - the cron job reports back a permission denied error.
I have tried setting the folder permissions to 0775 and still get a permission denied. However, when the permissions are 0777, then the cron job then works fine.
This seems very strange to me - why does the cron get a permission denied at 0755 but it works fine through the web app?

The probable answer is that the cron job executes under your user - and the directory is owned by apache (or www-data or nobody or whatever user your web server runs as).
To get it to work, you could set up the cron job to run as the web server user.
Something like this:
su -l www-data -c 'crontab -e'
Alternatively, you could change the permissions to 775 (read-write-execute for the owner and group, and read-execute for others) and set the group ownership of the folder to the user running the cron job.
However, you have to make sure that if you're deleting something or descending into folder which is created by apache, you could still run into problems (apache would create a file which it itself owns, and your user cannot delete it then, regardless of the directory permissions.
You could also look at some stuff like suphp or whatever is up to date - where the web server processes are ran under your username, depending on your system architecture.

It depends on which user you have defined the cronjob.
If you're root (not recommended) it should work. If you're the web-user (e.g. www-data on ubuntu) it should work as well.
sudo su - www-data
crontab -e

Permission are given to user-group-everybody. That's what the 3 characters denote.
Your php script runs as a different user&group than the cron job, so they observe different permissions.
Check chown and chgrp, or try to run the cron job with the same user.

if you are using cpanel to run a php, you can try something like this:
"php /home/algo/public_html/testcron.php" ...
just write: php (the rute of the script)/yourscritpt.php"

Related

Running PHP script via Cron

I'm codding a php script, using Instagram Private PHP Api.
It's work fine via SSH under "root" user, but when I try to run it via browser or cron, I getting error: Warning: chmod(): Operation not permitted in .....
I guess that something wrong with permissions, but I am not really good in server administration and can't understand what I can do =(
Please help, how I can fix this problem?
Because Apache (or the web server you're using) executes PHP using different Linux user (usually www-data), which obviously have different permission than the user account you used in access via SSH.
To tackle the problem, you first have to know the folder / file you're going to chmod() belongs to who. If it belongs to root, then it's not suggested to chmod via any scripts that is accessible by public due to security concerns.
If it belongs to your user name, say foo, you can change the ownership of the folder / file you're going to chmod() to be accessible by www-data group using chown() in SSH console, then you chmod() command can be executed without problem.
The user that PHP runs as must have permissions to chmod the given file or directory. If you're running this script via CRON, you get to set the user that PHP runs as right in the CRON job. If you're visiting the script in a browser, PHP is likely running as php or php-fpm or the web server user.
Simply ensure that the given file or folder is owned by the user that PHP runs as.
Note: It is not recommended that you run this script as root in CRON.
If you are editing /etc/crontab, make sure the user parameter (the one after week) is root.
If you are editing crontab via crontab -e, add user parameter crontab -eu root.

Why does file_put_contents have permission issues when run from the browser?

This question has been asked a couple of times up here, but I haven't found a solution yet. I have a Fedora 19 LAMP server and I just want to run the simple command: file_put_contents('test.txt', 'Hello there'); in order to confirm that my web server can use PHP to write data to files. I'm having trouble figuring out a proper permissions scheme. To start, just for development, Apache's document root is /var/www/html. This directory was originally owned by a user and group called www-data, but I changed the directory's group to the primary group of the owner of the httpd process, named apache. It is this owner that is active when PHP runs. I've confirmed this with the following:
As you see, the process owner is apache, the current direcory is /var/www/html/php-console. The directory is owned by www-data and members of the group apache have full access to it.
I have tried the following to get PHP to actually create a file in this location, but to no avail:
chmod 777 /var/www/html/php-console
chown apache /var/www/html/php-console
chgrp apache /var/www/html/php-console
cd /var/www/html; > test.txt; chmod 777 test.txt;
Nothing will work while this script is run from the browser. However, when I use file_put_contents with the PHP CLI, it works just like I would expect, provided that the user I'm entering commands as or its group has write permissions to this directory or test file.
So, from the command line, you see how www-data has read, write, and execute permissions to the folder I'm in. posix_getpwuid and posix_geteuid help you to find the owner of the Apache/PHP process, which in this case is the same as the user logged into the console. file_put_contents succesfully writes 8 bytes to the specified file. If I change the group or owner and group to something else, I get Permission denied, which absolutely makes sense.
If this works on the command line, then why not when I really want it to, i.e., while actually serving web pages???
Because you forgot to read the httpd_selinux(8) man page and give the directory the appropriate file context to allow the web server to write files there.

Apache runs php scripts as user nobody, cron runs php scripts as user

My default cpanel set up runs apache as user "nobody". So when I run a php script via a browser that outputs a file, that file has ownership nobody:nobody. When I run the script from a cron job logged in as user "fred", the output files are owned by fred:fred
I need both browser and cron to overwrite the same file. The issue I have is that if one "user" creates the file, the other one can't overwrite it.
Please can you let me know where the fundamental problem is and a possible solution. Permissions on the files are 0775.
Do I need to set up groups - adding the user to the same group as nobody? If so how?
How do I get the cron job to run as user nobody?
Many thanks,
Lloyd
Try you code after changing permission of the file as 0777.
But that creates a security issue as anyone can edit your file then.
I have a logic you need to implement to:
Create a shell script that copy the contents of temp file to your actual file.
From PHP you need to update only temp file and Shell can read it as temp file will have read permission for everyone.
Use ssh2_exec command to execute the shell script with your Linux UserName and Password.
For ssh2_exec manual follow this link : http://php.net/manual/en/function.ssh2-exec.php
Hope This will solve your problem.
Ok, my solution to this was to create a crontab for user "nobody".
I've got a standard cpanel installation and so went to /var/spool/cron created an entry for nobody. Ran crontab -e to edit it and install.
Now the php runs as nobody in the cron job exactly the same as if through a browser. All files written belong to nobody with only rw permissions for nobody.

File access difference for php file running with cron vs browser

A php file (say example.php) should write something into another file (say alma.txt). If example.php is run via a cron job, everything is ok, but when I call it through the browser, it does not write to alma.txt. Why?
A cron job runs under the user that owns the crontab file that have the cron job configured.
When you run your php from the cron daemon, is your user the one that is executing the command.
When you run your php script through the browser. in the web server this script is executed by the user that launched the apache process. In ubuntu is the user www-data for example.
This looks like a file permission issue. Just to be sure grant all permission to the file alma.txt.
chmod 777 alma.txt
and try again, if everything is ok, then was a permission issue, and i will suggest you to set the right permissions to the file. Maybe add the group www-data to the file and grant 775 to it.

Cron job and folders permissions - permission denied

I have a folder above the webroot that is used to temporarily store user files generated by a php web application. The files may, for example, be PDF's that are going to be attached to emails.
The folder permissions are set to rwxr-xr-x (0755). When executing a procedure from the web application, the files get written to this folder without any issues.
I have now also set up a cron job that calls the php script to execute that exact same procedure as above. However, the PDF cannot be saved into the above folder due to failed permissions - the cron job reports back a permission denied error.
I have tried setting the folder permissions to 0775 and still get a permission denied. However, when the permissions are 0777, then the cron job then works fine.
This seems very strange to me - why does the cron get a permission denied at 0755 but it works fine through the web app?
The probable answer is that the cron job executes under your user - and the directory is owned by apache (or www-data or nobody or whatever user your web server runs as).
To get it to work, you could set up the cron job to run as the web server user.
Something like this:
su -l www-data -c 'crontab -e'
Alternatively, you could change the permissions to 775 (read-write-execute for the owner and group, and read-execute for others) and set the group ownership of the folder to the user running the cron job.
However, you have to make sure that if you're deleting something or descending into folder which is created by apache, you could still run into problems (apache would create a file which it itself owns, and your user cannot delete it then, regardless of the directory permissions.
You could also look at some stuff like suphp or whatever is up to date - where the web server processes are ran under your username, depending on your system architecture.
It depends on which user you have defined the cronjob.
If you're root (not recommended) it should work. If you're the web-user (e.g. www-data on ubuntu) it should work as well.
sudo su - www-data
crontab -e
Permission are given to user-group-everybody. That's what the 3 characters denote.
Your php script runs as a different user&group than the cron job, so they observe different permissions.
Check chown and chgrp, or try to run the cron job with the same user.
if you are using cpanel to run a php, you can try something like this:
"php /home/algo/public_html/testcron.php" ...
just write: php (the rute of the script)/yourscritpt.php"

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