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     SEGBRK(2)                                               SEGBRK(2)

     NAME
          segbrk - change memory allocation

     SYNOPSIS
          #include <u.h>
          #include <libc.h>

          void* segbrk(void *saddr, void *addr)

     DESCRIPTION
          Segbrk sets the system's idea of the lowest unused location
          of a segment to addr rounded up to the next multiple of a
          page size, typically 4096 bytes.  The segment is identified
          by saddr which may be any valid address within the segment.

          A call to segbrk with a zero addr argument returns the base
          address of the segment without altering its size.

          The system will prevent segments from overlapping and will
          not allow the length of the text, data, or stack segment to
          be altered.

     SOURCE
          /sys/src/libc/9syscall

     SEE ALSO
          brk(2), segattach(2), segflush(2)
          /proc/*/segment

     DIAGNOSTICS
          Sets errstr. Segbrk returns (void*)-1 on error.

     BUGS
          The segbrk system call may go away or be re-implemented to
          give more general segment control, subsuming the functions
          of brk(2), segflush(2) and segfree in segattach(2).

     Page 1                       Plan 9            (printed 10/24/25)