syncom/bash-cpu-hogger.md

## bash-cpu-hogger.md

      
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              bash-cpu-hogger.md
            
          
    The following bash script hogs CPU resources (and thus drains laptop battery quickly):
#!/bin/bash
# CPU hogger, using 8 threads
hog='dd if=/dev/urandom | bzip2 -9 >> /dev/null'
cmd=$(echo -n ${hog}; printf " | ${hog}%.0s" {1..7};  echo -n '& read; killall dd')
eval ${cmd}

Explaination:

'dd if=/dev/urandom | bzip2 -9' reads random data from /dev/urandom, and compresses
it using the best (most CPU consuming) bzip2 algorithm option. This is the CPU hog.
'cmd' is a string constructed as a bash command that repeats the CPU hog above 8
times.
By adding the &, we send the hoggers to background. We then read from stdin and kill
all the hoggers.
The last line evaluates the 'cmd' string as a command.

The script took a (strong) hint from and thank the StackOverflow thread:
https://stackoverflow.com/questions/2925606/how-to-create-a-cpu-spike-with-a-bash-command.