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END(3)			   Linux Programmers Manual		       END(3)

       etext, edata, end - end of program segments

       extern etext;
       extern edata;
       extern end;

       The addresses of these symbols indicate the end of various program seg

       etext  This is the first address past the end of the text segment  (the
	      program code).

       edata  This  is	the first address past the end of the initialized data

       end    This is the first address past the end of the uninitialized data
	      segment (also known as the BSS segment).

       Although  these	symbols  have long been provided on most Unix systems,
       they are not standardized; use with caution.

       The program must explicitly declare these symbols; they are not defined
       in any header file.

       On some systems the names of these symbols are preceded by underscores,
       thus: _etext, _edata, and _end.	These symbols  are  also  defined  for
       programs compiled on Linux.

       At  the start of program execution, the program break will be somewhere
       near &end (perhaps at the start of the following page).	 However,  the
       break  will change as memory is allocated via brk(2) or malloc(3).  Use
       sbrk(2) with an argument of zero to find the current value of the  pro
       gram break.

       When run, the program below produces output such as the following:

	   $ ./a.out
	   First address past:
	       program text (etext)	  0x8048568
	       initialized data (edata)   0x804a01c
	       uninitialized data (end)   0x804a024


       extern char etext, edata, end; /* The symbols must have some type,
					  or "gcc -Wall" complains */

       main(int argc, char *argv[])
	   printf("First address past:\n");
	   printf("    program text (etext)	 %10p\n", &etext);
	   printf("    initialized data (edata)  %10p\n", &edata);
	   printf("    uninitialized data (end)  %10p\n", &end);


       objdump(1), readelf(1), sbrk(2), elf(5)

       This  page  is  part of release 3.05 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU				  2008-07-17				END(3)

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