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phpechoshell-exec

php shell_exec echo

I'm working on interfacing a microcontroller with a lamp server. I am trying to run the command echo -e -n "data \r" > /dev/ttyUSB0 using shell_exec in php but with no results. It works just fine from the command line. Doing a little experimenting, I discovered that echo -e -n "1 \r" actually echoes -e -n 1. Is there a reason it won't take the -e or -n options? Here's my code:

    <?php
    shell_exec('echo -e -n "1 \r" > /dev/ttyUSB0');
    ?>
Solution

  • Instead of using shell_exec and echo, why not use PHP's filesystem functions?

    file_put_contents('/dev/ttyUSB0', "1 \r");