It depends what of environmet (and C library code, that requre initialization) you using. Because is possible writing programm in C, that not used any library call, and do not requre environment set up.
For examle loking this: **broken link removed**
p.s.
I remember that long time ago (about 14 years), I making shortest programms in Borland C 3.1 for DOS, with com file length, less than 100 bytes ....