lib/human.h

   1 #ifndef HUMAN_H_
   2 # define HUMAN_H_ 1
   3
   4 /* Before including this file, you need something like the following:
   5
   6         #if HAVE_CONFIG_H
   7         # include <config.h>
   8         #endif
   9
  10         #if HAVE_STDBOOL_H
  11         # include <stdbool.h>
  12         #else
  13         typedef enum {false = 0, true = 1} bool;
  14         #endif
  15
  16         #if HAVE_INTTYPES_H
  17         # include <inttypes.h>
  18         #else
  19         # if HAVE_STDINT_H
  20         #  include <stdint.h>
  21         # endif
  22         #endif
  23
  24         #include <limits.h>
  25
  26    so that the proper identifiers are all declared.  */
  27
  28 /* A conservative bound on the maximum length of a human-readable string.
  29    The output can be the square of the largest uintmax_t, so double
  30    its size before converting to a bound.
  31    302 / 1000 is ceil (log10 (2.0)).  Add 1 for integer division truncation.
  32    Also, the output can have a thousands separator between every digit,
  33    so multiply by MB_LEN_MAX + 1 and then subtract MB_LEN_MAX.
  34    Finally, append 3, the maximum length of a suffix.  */
  35 # define LONGEST_HUMAN_READABLE \
  36   ((2 * sizeof (uintmax_t) * CHAR_BIT * 302 / 1000 + 1) * (MB_LEN_MAX + 1) \
  37    - MB_LEN_MAX + 3)
  38
  39 /* Options for human_readable.  */
  40 enum
  41 {
  42   /* Unless otherwise specified these options may be ORed together.  */
  43
  44   /* The following three options are mutually exclusive.  */
  45   /* Round to plus infinity (default).  */
  46   human_ceiling = 0,
  47   /* Round to nearest, ties to even.  */
  48   human_round_to_nearest = 1,
  49   /* Round to minus infinity.  */
  50   human_floor = 2,
  51
  52   /* Group digits together, e.g. `1,000,000'.  This uses the
  53      locale-defined grouping; the traditional C locale does not group,
  54      so this has effect only if some other locale is in use.  */
  55   human_group_digits = 4,
  56
  57   /* When autoscaling, suppress ".0" at end.  */
  58   human_suppress_point_zero = 8,
  59
  60   /* Scale output and use SI-style units, ignoring the output block size.  */
  61   human_autoscale = 16,
  62
  63   /* Prefer base 1024 to base 1000.  */
  64   human_base_1024 = 32,
  65
  66   /* Append SI prefix, e.g. "k" or "M".  */
  67   human_SI = 64,
  68
  69   /* Append "B" (if base 1000) or "iB" (if base 1024) to SI prefix.  */
  70   human_B = 128
  71 };
  72
  73 char *human_readable (uintmax_t, char *, int, uintmax_t, uintmax_t);
  74
  75 int human_options (char const *, bool, uintmax_t *);
  76
  77 #endif /* HUMAN_H_ */