mdw@git.distorted.org.uk Git - qmail/blob - alloc.3

   1 .TH alloc 3
   2 .SH NAME
   3 alloc \- allocate memory
   4 .SH SYNTAX
   5 .B #include <alloc.h>
   6
   7 char *\fBalloc\fP(\fInew\fR);
   8
   9 void \fBalloc_free\fP(\fIx\fR);
  10
  11 void \fBalloc_re\fP(&\fIx\fR,\fIold\fR,\fInew\fR);
  12
  13 char *\fIx\fR;
  14 .br
  15 unsigned int \fIold\fR;
  16 .br
  17 unsigned int \fInew\fR;
  18 .SH DESCRIPTION
  19 .B alloc
  20 allocates enough space from the heap for
  21 .I new
  22 bytes of data,
  23 adequately aligned for any data type.
  24 .I new
  25 may be 0.
  26 .B alloc
  27 returns a pointer to the space.
  28 If space is not available,
  29 .B alloc
  30 returns 0,
  31 setting
  32 .B errno
  33 appropriately.
  34
  35 .B alloc_free
  36 returns space to the heap.
  37
  38 .B alloc_re
  39 expands the space allocated to
  40 .I x
  41 from
  42 .I old
  43 bytes to
  44 .I new
  45 bytes.
  46 It allocates new space,
  47 copies
  48 .I old
  49 bytes from the old space to the new space,
  50 returns the old space to the heap,
  51 and changes
  52 .I x
  53 to point to the new space.
  54 It then returns 1.
  55 If space is not available,
  56 .B alloc_re
  57 returns 0,
  58 leaving the old space alone.
  59 .SH "SEE ALSO"
  60 sbrk(2),
  61 malloc(3),
  62 error(3)