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Annotation of cci/usr/src/man/man2/brk.2, revision 1.1

1.1     ! root        1: .TH BRK 2
        !             2: .SH NAME
        !             3: brk, sbrk \- change data segment space allocation
        !             4: .SH SYNOPSIS
        !             5: .B int brk (endds)
        !             6: .br
        !             7: .B char *endds;
        !             8: .PP
        !             9: .B  char *sbrk (incr)
        !            10: .br
        !            11: .B int incr;
        !            12: .SH DESCRIPTION
        !            13: .I Brk\^
        !            14: and
        !            15: .I sbrk\^
        !            16: are used to change dynamically the amount of space allocated
        !            17: for the calling process's data segment; see
        !            18: .IR exec (2).
        !            19: The change is made by resetting the process's break value and allocating
        !            20: the appropriate amount of space.
        !            21: The break value
        !            22: is the address of the first location beyond the end of the data segment.
        !            23: The amount of allocated space increases as the break value increases.
        !            24: The newly allocated space is set to zero.
        !            25: .PP
        !            26: .I Brk\^
        !            27: sets the break value to
        !            28: .I endds\^
        !            29: and changes the allocated space accordingly.
        !            30: .PP
        !            31: .I Sbrk\^
        !            32: adds 
        !            33: .I incr\^
        !            34: bytes to the break value and changes the allocated space accordingly.
        !            35: .I Incr\^
        !            36: can be negative, in which case the amount of allocated space is decreased.
        !            37: .PP
        !            38: .I Brk\^
        !            39: and
        !            40: .I sbrk\^
        !            41: will fail without making any change in the allocated space if one or more of
        !            42: the following are true:
        !            43: .IP
        !            44: Such a change would result in more space being allocated
        !            45: than is allowed by a system-imposed maximum (see
        !            46: .IR ulimit (2)).
        !            47: .SM
        !            48: \%[ENOMEM]
        !            49: .IP
        !            50: Such a change would result in the break value being greater than or equal
        !            51: to the start address of any attached shared memory segment (see
        !            52: .IR shmop (2)).
        !            53: .SH RETURN VALUE
        !            54: Upon successful completion,
        !            55: .I brk\^
        !            56: returns a value of 0 and
        !            57: .I sbrk\^
        !            58: returns the old break value.
        !            59: Otherwise, a value of \-1 is returned and
        !            60: .I errno\^
        !            61: is set to indicate the error.
        !            62: .SH SEE ALSO
        !            63: exec(2), shmop(2), ulimit(2).
        !            64: .\"    @(#)brk.2       6.2 of 9/6/83

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