I am trying to run a simple command say ls -l on OpenBSD shell (uname -r: 6.4) using php 5.6.
<?php
$output = shell_exec('ls -l');
echo "<pre>$output</pre>";
?>
There is no output of above code. Just pre tag upon inspecting elements
So what is causing this issue? I tried using the same command using
System
Shell_exec
exec
No luck. What would be the cause of this ? Probably System/shell_exec not supported in OpenBSD's version of Php or something else.
Thanks in advance!
You haven't given enough information for a definitive answer, but my
guess is that you run php through php-fpm, which is by default chrooted
to /var/www. Since shell_exec and system first call /bin/sh and you
most likely didn't copy it to var/www/bin/sh it can't find your shell.
After that you'd also need to copy the binaries (in this case ls) to
your chroot and possible library dependencies (not needed for files
under /bin).
Hope this helps for illustrative purposes, but please don't use it in
production.
Related
I try to have separate ssp modes during connection using Bluetooth btmgmt utility. Basic idea is scan current device OUI and select ssp on/off modes. But I can't get any answer from neither btmgmt con or btmgmt info commands when I put them into .service files. My system is Arch Linux arm 32-bit and bluez stack version is 5.55-1. I tried
[Unit]
Description=check Bluetooth address
[Service]
Type=oneshot
ExecStart=/usr/bin/bash -c '/usr/bin/btmgmt info >> /usr/local/lib/mac 2>&1'
without any success: it just puts nothing in output file. Some tricks like add
User=root
Group=root
or substitute ExecStart with
ExecStart=/bin/bash -c 'echo -e "$(btmgmt con)" >> /usr/local/lib/mac 2>&1
did nothing. I tried changed thing by putting btmgmt stuff in different bash script instead of start them right from service file, i.e.
ExecStart=/usr/local/lib/test1
to no avail. I'm confused completely, because of:
It doesn't seem to be general btmgmt thing problem, because I can set ssp mode from service files
in very simple manner, just using
ExecStart=btmgmt off
or
ExecStart=btmgmt off
even without full path.
It doesn't seem to be redirecting command error as well, because if I add
ExecStartPre=/usr/bin/bash -c '/usr/bin/fdisk -l > /usr/local/lib/mac 2>&1'
it does work without any problem and I see fdisk info in file (I use fdisk because it requires elevated rights same as btmgmt one).
Moreover, btmgmt info works in the same way, i.e. shows nothing in out file. It makes me think something is wrong in output of btmgmt. I talk about output because input parameters work fine in btmgmt ssp on/of commands and journalctl and systemct don't show any errors in btmgmt con/info cases, so it seems to like output generating successfully but then sending somewhere to outer space, but I'm not sure completely.
Thanks for any help in advance
Well, I make a statement: btmgmt is quite intended to be used for output at any manner, but they tried make a zillion variants of output which directed to exact result it should be: bug is buried somewhere deep inside of bt_shell_printf and struct data. I'm not ready run through all that disgusting documented code (I mean total absence of comments or more-or-less satisfactory mans), so I ended up with a liitte bit hacked version of utility downgraded to simple fprintf in output, leaving only commands I need: con, ssp, power and simplified until only current setting printing info. Everything works fine, and I can use that kind of btmgmt not with systemd only, but even with udev rules (indirectly, of course)
I know this is an old question, but I had the same problem, and managed to fix it after hours and hours of trying.
I don't know why in the world this happens to be so hard with btmgmt but here's the fix:
[Unit]
After=bluetooth.service
Description=Bluetooth service
[Service]
ExecStart=<your-process>
Group=root
StandardInput=tty
TTYPath=/dev/tty2
TTYReset=yes
TTYVHangup=yes
Type=simple
User=root
Basically, by occupying a TTY, btmgmt will think it's running in an interactive terminal, and will output as usual.
Hope this saves anyone the hell I've been through!
I am using Ubuntu via WSL 2.0 on Windows 10 and would like to run Texlive from the Windows command line. To do so I prepended the Texlive folder to the path in /etc/environment (I also tried a number of other locations eg. $HOME/.bashrc):
C:\Users\scott\Documents>wsl echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Windows/system32:...
C:\Users\scott\Documents>wsl
scott#SCOTT-PC:/mnt/c/Users/scott/Documents$ echo $PATH
/usr/local/texlive/2020/bin/x86_64-linux:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Windows/system32:...
Why is there a difference between these two paths? Is it possible to change the first PATH variable?
To be honest, when I first looked at this question, I thought it would be an easy answer. Oh how wrong I was. There are a lot of nuances to how this works.
Let's start with the fairly "easy" part, though. The main difference between the first method and the second:
wsl by itself launches into a login (and interactive) shell
the shell launched with wsl echo $PATH is neither a login shell nor an interactive shell
So the first will source both login scripts (e.g. ~/.profile) and interactive startup scripts (e.g. ~/.bashrc). The second form does not get to source either of these.
You can see this a different way (and get to the solution) with the following commands:
wsl -e bash -c 'echo $PATH'
wsl -e bash -li -c 'echo $PATH'
The -li forces bash to run as a login and interactive shell, thus sourcing all of the applicable startup scripts. And, as #bovquier points out in the comments, a single quote is needed here to prevent PowerShell from interpolating the $ before it gets to Bash. That, or escape it.
You should be able to run TeX Live the same way, just replacing the "echo $PATH" with the startup command you need for TeX Live.
A second option would be to create a script that both adds the path and runs the command, and just launch that script through wsl /path/to/script.sh
That said, I honestly don't think that your current login/interactive PATH is coming from /etc/environment. In my testing, at least, /etc/environment has no use in WSL, and that's to be expected. /etc/environment is only sourced by PAM modules, and with no login check performed by WSL, there's no reason to invoke PAM in either the wsl nor the wsl echo $PATH commands.
I'd expect that you still have the PATH setting in ~/.bashrc or somewhere similar), and that's where the shell is picking it up from at the moment.
While this isn't necessarily critical to understanding the answer, you might also wonder, if /etc/environment isn't used for setting the default (non-login, non-interactive) path in WSL, what is? The answer seems to be that it is hard-coded into the init that starts up WSL. That init is also what appends the Windows path (assuming you don't have that feature disabled in /etc/wsl.conf).
I've posted this issue on the google groups area for mapnik already, so I'm just going to c/p from there:
I've been troubleshooting this issue for a couple days, now. Bear with me for context:
Starting from a freshly-untarred source of mapnik 2.2.0 on RHEL 6.5:
First off, running "./configure" (which just calls scons/scons.py) works great. Finishes correctly, then I run make + make install and I get exactly what I want built and installed.
My goal has been to create a mapnik 2.2.0 RPM for internal use. Please do not suggest using an "official" mapnik RPM instead (or any other already-built mapnik RPM), as my entire purpose here is to build mapnik from source and create my own RPM.
That being said, when my RPM gets to its %build phase and runs ./configure, it freezes while scons checks for freetype-config. I've let it sit for hours, and nothing happens.
After I looked at the generated config.log file, it would appear that configure is failing on an "awk" command that goes something like this:
awk '{print $\(NF-1\)}'
The command is performed on the string that results from the command:
/usr/bin/freetype-config --libs --cflags
I'm wondering, first of all, how to fix this, but second of all why this would work manually, but fail when the rpmbuild process gets to the ./configure command. I've made sure that the same user (myself) is running both ./configure commands on the exact same files.
My third question would be: why does the configure step freeze on this issue, instead of throwing some sort of error and stopping?
Note that the problem with the "awk" command is the backslashes--the error is:
awk: {print $\(NF-1\)}
^ backslash not last character on line
When I remove the backslashes, the command succeeds. Whether or not removing the backslashes is the correct thing to do in the long run, I do not know.
It would seem this is some sort of python string-parsing / encoding issue, but I'm unsure. What really confuses me is why this works manually and fails when the rpmbuild tries to do it.
My only thought is that there's some difference between the rpmbuild environment and my shell that I configured on. What it is, I do not know.
Thank you for any assistance you can provide. If I can provide any more context, please let me know.
UPDATE: an svn command runs after the awk failure, but is missing whatever number gets passed after the -r option. I'm wondering if this could be causing the hang...thoughts?
I've written a cgi script that processes data that is generated by another program. The problem is that this file is located outside the cgi-bin. How can I make sure that my perl scripts can read this file? I've already tried changing the permissions of this file and I also tried to make a link in the cgi-bin folder but Apache is too smart for that. I guess possible solutions are:
Edit the Apache config file in a way that Apache can read files outside the cgi-bin.
Run the cgi script with a 'portable' webserver. Like you can do with python (python -m http.server [port]). Unfortunately this does not execute the perl cgi scripts.
I'm kind of stuck how to do either one of the solutions.
Your CGI-script could access anything on your OS unless you run the apache under a sort of jail, in this case the your can read anything in the jail. (Of course, if the apache process has permissions to read the file).
e.g the next simple script will print out your password file
use strict;
use warnings;
use CGI;
my $q=CGI->new();
print $q->header();
print qx(cat /etc/passwd);
About the modern perl web-app development, read the following:
PSGI: What is it and what's the fuss about?
plack advent calendar: http://advent.plackperl.org/2009/12/day-1-getting-plack.html (buy the ebook if you can here: http://handbook.plackperl.org )
https://github.com/plack/Plack
Get some modern web-framerowk from CPAN - here are many (maybe too many) - the most known are:
Dancer (Dancer2)
Mojolicious
Poet/Mason
and of course, the big-gun: Catalyst
I personally mostly using
Poet/Mason
Mojolicious
EDIT
In your cgi-bin should exists a script called printenv.pl. Try:
chmod 755 printenv.pl
and point your browser to http://address/cgi-bin/printenv.pl You will get, the apache environment. See, you must know the basics of operating system commands and how the web works to succesfully run an web-application. It is impossible to write down everything in one answer, you need to use google, read answers to other questions here and such.
Also, in the above script, you can change the cat /etc/passwd to any other shell command for testing only what your cgi-script can or can not.
I've solved this problem by using plackup in combination of PSGI.
use CGI::Emulate::PSGI;
use CGI::Compile;
my $sub = CGI::Compile->compile("location/to/script.cgi");
my $app = CGI::Emulate::PSGI->handler($sub);
If you run plackup file.psgi, it sets up a local webserver that runs as the current user. Problem solved.
I'm attempting to pipe an email to PHP with my Postfix mail server, using the technique mentioned here and have encountered the following error...
Mar 16 22:52:52 s15438530 postfix/pipe[9259]: AD1632E84C63: to=<php#[myserver].com>, relay=plesk_virtual, delay=0.61, delays=0.59/0/0/0.02, dsn=4.3.0, status=deferred (temporary failure. Command output: /bin/sh: /var/www/vhosts/[myserver].com/httpdocs/clients/emailpipe/email2php.php: Permission denied 4.2.1 Message can not be delivered at this time )
I'd really appreciate if anyone could shed some light on this issue for me. I've tried 777'ing the emailpipe directory, to no avail. Where am I going wrong?
Many thanks.
From the postfix docs...
For security reasons, deliveries to command and file destinations are performed with the rights of the alias database owner. A default userid, default_privs, is used for deliveries to commands/files in root-owned aliases.
So you have two options, either set the default_privs in main.cf to match the ownership of the email2php file.
Alternatively, there should be a way to create an alias database that is owned by the user instead of postfix/nobody. I haven't tried this before though so can't advise.
I have fixed this issue by disabling the SELINUX.
Make sure that you have
#!/usr/bin/php
<?php
(or whatever your path to php is - do "which php" on the server)
at the top of each of your php scripts and that each of the php script files is executable
chmod +x /var/.../email2php.php
Also, make sure that you can test the script from the command line:
cat some_rfc822_email.txt | /var/.../email2php.php
and get the result that you want
To fix this issue, you'll want to chown or chmod /var/www/vhosts/[myserver].com/httpdocs/clients/emailpipe/email2php.php to executable by your postfix user. Alternately, you'll want to redefine this user to execute the file successfully.
Simply changing the permissions of your directory (unless you used -R) won't be sufficient.
To illustrate why this works, consider the following toy example:
<me>#harley:~$ touch test
<me>#harley:~$ ls -al test
-rw-r--r-- 1 <me> <me> 0 2012-03-26 23:44 test
<me>#harley:~$ sh test
<me>#harley:~$
<me>#harley:~$ ./test
bash: ./test: Permission denied
<me>#harley:~$ chmod 755 test
<me>#harley:~$ ./test
<me>#harley:~$
In order to execute a file directly through the running shell, it needs to be set as executable. Other invocations (for example, sh email2php.php or php email2php.php) only require read access, because they're chaining execution off a different file entirely.
For what's likely to be causing the issue in the first place, see here.