So I have a php script which I execute using the following command:
php -f my_script.php myArguments
The script is under version control using svn. I just updated it, pasted the command to run it into a terminal, and executed it. However, there is no output. Not a failure message, not it printing anything, nothing. It looks like it never starts. Kind of like the following:
me:/srv/scripts# php -f my_script.php myArguments
me:/srv/scripts#
Other scripts will run just fine.
It is difficult for me to come up with an SSCCE, as I can't really share the code that is causing this, and I haven't been able to replicate this behavior intentionally. I have, however, seen this twice now. If I save my changes, revert the file, and paste them back in, there is a strong chance it will run just fine.
However, I am concerned by not knowing what is causing this odd behavior. Is there a whitespace character or something that tells PHP not to start, or output anything?
Here is what I've tried after seeing this behavior:
Modifying the script so it is a simple echo 'hello'
Putting nonsense at the beginning of the script, so it is unparseable.
Pasting in code from a working script
Banging my head on a wall in frustration
Trying it in another terminal/putty ssh connection.
Here's where it gets interesting: It actually works in a different terminal. It does everything as expected.
So does anyone have any ideas what might be causing this, or things I should try in order to determine the problem?
EDIT:
The "different terminal" is still the terminal application, just a new one.
I have sufficient permissions to execute the file, but even if I didn't, it should spit out a message saying I don't.
I intentionally introduced syntax errors in hopes that I would get PHP to spit out a parse error. There was still no output.
display_errors might be disabled before runtime. You can turn it on manually with the -d switch:
php -d display_errors=1 -f my_script.php myArguments
I came across the same issue, and no amount of coercing PHP to display_errors or checking for syntax with -l helped
I finally solved our problem, and perhaps you can find some help with this solution
Test your script without using your php.ini:
php -n test_script.php
This will help you hone in on the real cause - PHP configuration, someone else's script, or your script
In my case, it was a problem with someone else's script which was being added via the auto_prepend_file directive in the php.ini. (Or more specifically, several files and functions later as I drilled through all the code adding debug as I went - on a side note, you may find that using fwrite(STDOUT, "debug text\n"); invaluable when trying to debug this type of issue)
Someone had added a function that was getting run through the prepend file, but had used the @ symbol to suppress errors on a particular function call. (You might have a similar problem but not specifically related to the php.ini if you have any includes in your test script bringing in other code)
The function was failing and caused the silent death of PHP, nothing to do with my test script
You will find all sorts of warnings about how using the @ symbol causes the exact problem I had, and perhaps you're having, http://php.net/manual/en/language.operators.errorcontrol.php.
Reproduction of similar symptoms:
Take a fully functional PHP environment, and break your CLI output by adding this the top of your script
@xxx_not_a_real_function_name_xxx();
So you may just have a problem with the php.ini, or you (or someone else) may have used @ not realising the serious (and frustrating and time consuming) consequences that it causes in debugging
I experienced PHP CLI failing silently on a good script because of a memory limit issue. Try with:
php -d memory_limit=512M script.php
