Can someone explain me what this code do?

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Hello

Im completly noob with this kind of code, someone can explain to me this code? i think this code compare the serial number. but i dont undestand it line by line.

if [ -f /opt/k/newApp/kCfg.jar ]; 
then 
   sudo mv /opt/k/newApp/kCfg.jar /opt/k/kCfg.jar 
fi 
sn=$(grep -Po '^Serial\s*:\s*\K[[:xdigit:]]{16}' /proc/cpuinfo) 
sudo java -jar /opt/ka/kCfg.jar -S$sn & 
chromium -kiosk -incognito http://testserver/Default.aspx?serial=$sn

thanks

What I have tried:

i think this code compare the serial number. but i dont undestand it line by line.

Posted 7-Jan-19 4:02am

drvfn

Updated 7-Jan-19 4:37am

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k5054 · Accepted Answer · 2019-01-07T04:37:00

That's pretty straight forward shell script:

the [ -f ... ] expression is a test, in this case -f tests for file existence (see man test)
if the test succeeds, then we get root privileges via sudo and move the new executable into position

This line

C++

sn=$(grep -Po '^Serial\s*:\s*\K[[:xdigit:]]{16}' /proc/cpuinfo)

runs grep's the /proc/cpuinfo file in a sub shell (that's what $() does, also written with back-ticks ``) for the serial number and assigns the value to variable sn
we then run a java program, again as root
and finally, we run chromium in kiosk mode, starting an incognito page at starting from the web site given.