extern end;

extern etext;

extern edata;


These names refer neither to routines nor to locations with interesting contents. The address of etext is the first address above the program text, edata above the initialized data region, and end above the uninitialized data region.

When execution begins, the program break coinicides with end, but the program break may be reset by the routines of brk(2P) , malloc(3P) , standard input/output ( stdio(3P) , and so on. Thus, the current value of the prgram break should be determined by sbrk(0) (see brk(2P) ).


brk(2P) , malloc(3P)