Make builds nice

Nice is an often forgotten but very useful part of coreutils. It adjusts the priority of the given command which in GNU/Linux (and UNIX) is called niceness. This name is quite convenient as it avoids the unnecessary confusion as to increase the priority the value has to be decreased. So a process with a high niceness value is "nice" to other processes.

The good thing about niceness is that it is inherited to child processes. So you just need to run your build script or make with nice:

nice -n 11 make -j8 all

All spawned processes (sub-make, compiler, linker etc.) get the same niceness value.

This can make a busy CI system responsive even under high load.

python's shortcuts

Let's try to optimize some simple python code like this:

a = ['eggs', 'bacon']

no_spam = True
for x in a:
    if x == 'spam':
        no_spam = False
if no_spam:
    print('there is no spam in it')

This might seem pretty obvious but an often forgotten fact is that a python's for loop may have an optional else clause.

So to make it slightly shorter and avoid using an additional variable:

a = ['eggs', 'bacon']

for x in a:
    if x == 'spam':
        break
else:
    print('there is no spam in it')

If you want to make if even shorter you can use the built-in functions any and map instead of the for loop:

a = ['eggs', 'bacon']

if not any(map(lambda x: True if x == 'spam' else False, a)):
    print('there is no spam in it')