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НАЗВАНИЕ

       etext, edata, end - end of program segments

СИНТАКСИС

       extern etext;
       extern edata;
       extern end;

ОПИСАНИЕ

       The addresses of these symbols indicate the end of various
       program segments:

       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 segment.

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

СТАНДАРТЫ

       None.

ИСТОРИЯ

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

ПРИМЕЧАНИЯ

       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 program break.

ПРИМЕРЫ

       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

   Program source

       #include <stdio.h>
       #include <stdlib.h>

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

       int
       main(void)
       {
           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);

           exit(EXIT_SUCCESS);
       }

СМОТРИТЕ ТАКЖЕ

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

КОЛОФОН

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-06-15                         end(3)

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