The Ten Commandments for C Programmers

I Thou shalt run lint frequently and study its pronouncements with care,
for verily its perception and judgment oft exceed thine.

II Thou shalt not follow the NULL pointer, for chaos and madness await
thee at its end.

III Thou shalt cast all function arguments to the expected type if they are
not of that type already, even when thou art convinced that this is
unnecessary, lest they take cruel vengeance upon thee when thou least
expect it.

IV If thy header files fail to declare the return types of thy library
functions, thou shalt declare them thyself with the most meticulous
care, lest grievous harm befall thy program.

V Thou shalt check the array bounds of all strings (indeed, all arrays),
for surely where thou typest ``foo'' someone someday shall type
``supercalifragilisticexpialidocious''.

VI If a function be advertised to return an error code in the event of
difficulties, thou shalt check for that code, yea, even though the
checks triple the size of thy code and produce aches in thy typing
fingers, for if thou thinkest ``it cannot happen to me'', the gods
shall surely punish thee for thy arrogance.

VII Thou shalt study thy libraries and strive not to re-invent them without
cause, that thy code may be short and readable and thy days pleasant
and productive.

VIII Thou shalt make thy program's purpose and structure clear to thy
fellow man by using the One True Brace Style, even if thou likest it
not, for thy creativity is better used in solving problems than in
creating beautiful new impediments to understanding.

IX Thy external identifiers shall be unique in the first six characters,
though this harsh discipline be irksome and the years of its necessity
stretch before thee seemingly without end, lest thou tear thy hair out
and go mad on that fateful day when thou desirest to make thy program
run on an old system.

X Thou shalt foreswear, renounce, and abjure the vile heresy which
claimeth that ``All the world's a VAX'', and have no commerce with
the benighted heathens who cling to this barbarous belief, that the
days of thy program may be long even though the days of thy current
machine be short.