Can't run Linux "awk" command in script from PHP - php

Question

I have the shell script "test.sh":
#!/system/bin/sh
PID=$(ps | grep logcat | grep root |grep -v grep | awk '{print $2}')
echo "Using awk: $PID"
PID=$(ps | grep logcat | grep root |grep -v grep | cut -d " " -f 7 )
echo "Using cut: $PID"
When I run the script from PHP:
exec("su -c sh /path/to/my/script/test.sh");
I got this output:
Using awk:
Using cut: 6512
So "cut" command is work but "awk" command doesn't when I run the script from PHP, but when I run it from terminal:
# sh test.sh
I can get both awk and cut work fine! This how look like the output of "ps":
USER PID PPID VSIZE RSS WCHAN PC NAME
root 6512 5115 3044 1108 poll_sched b6e4bb0c S logcat
Do I missed something?

Answer 1

You should learn how to debug first
You said
So "cut" command is work but "awk" command doesn't when I run the
script from PHP, but when I run it from terminal:
I wonder how ?
actually throws error like below, in CLI
$ php -r 'exec("su -c sh /path/to/my/script/test.sh");'
su: user /path/to/my/script/test.sh does not exist
You first need below syntax while debugging code
// basic : stdin (0) stdout (1) stderr (2)
exec('your_command 2>&1', $output, $return_status);
// to see the response from your command
// su: user /path/to/my/script/test.sh does not exist
print_r($output);
Remember :
su gives you root permissions but it does not change the PATH variable and current working directory.
The operating system assumes that, in the absence of a username, the
user wants to change to a root session, and thus the user is prompted
for the root password
[akshay#localhost Desktop]$ su
Password:
[root#localhost Desktop]# pwd
/home/akshay/Desktop
[root#localhost Desktop]# exit
exit
[akshay#localhost Desktop]$ su -
Password:
[root#localhost ~]# pwd
/root
Solution:
You should allow executing your script without password prompt ( don't use su use sudo )
To allow apache user to execute your script and some commands you may make entry like below in /etc/sudoers
# which awk => give you awk path
# same use in your script also, or else set path variable
www-data ALL=NOPASSWD: /path/to/my/script/test.sh, /bin/cut, /usr/bin/awk
So it becomes :
// assuming your script is executable
exec("sudo /path/to/my/script/test.sh 2>&1", $output);
print_r($output);