用Cron运行C ++程序

Question

I'm trying to run a c++ program on my server, which, for now, is updating a MySQL database. I'm running it with Cron. The program is compiling and running on my own computer (Ubuntu 10.10), but I can seem to get something working on my server.

I checked if cron is working for me with a PHP script, but I don't know what to do to run a c++ program. In directAdmin I'm using the command:

/home/rogier/domains/ditiseenwinkel.nl/public_html/test/program &>/home/rogier/domains/ditiseenwinkel.nl/public_html/test/testsql2.log  

Where program is my compiled program. Strange thing: the logfile is empty.

What am I doing wrong? And how should I run a c++ program via Cron?

Thanks in advance!

Answer 1

Was the program compiled on the same server? If not - you should compile the sourcecode on the same server.

Answer 2

A C++ program should be compiled into an executable. Once you get that far the language it was written in doesn't matter any more!

Does the command line given run on the server and produce output (ie via command line, not cron)? If so the app may be depending on some environment that cron doesn't have.

What about running it without redirection?

Do you have write permission to the logfile?

Answer 3

To Cron, it does not matter which type of program C++/PHP/Python/..etc you are running as far as you can execute that command from the shell. If a command you write on the shell works, it should work for cron too.

However be aware that the environment vars for cron might be completely different. That is the number 1 cause of problems with cron. Even if you install a cron script for your own user, you might be surprised that the cron environment does not have any PATH. Hence you have to specify the full path for simple system commands lie /bin or /usr/bin

Like other users said, there might be a case of access rights if the command is executed by other user than yours. I usually test my dump files with the safest path "/tmp" (except if the user is chrooted)