libbb/duration.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 2018 Denys Vlasenko
   6  *
   7  * Licensed under GPLv2, see file LICENSE in this source tree.
   8  */
   9 //config:config FLOAT_DURATION
  10 //config:       bool "Enable fractional duration arguments"
  11 //config:       default y
  12 //config:       help
  13 //config:       Allow sleep N.NNN, top -d N.NNN etc.
  14
  15 //kbuild:lib-$(CONFIG_SLEEP)   += duration.o
  16 //kbuild:lib-$(CONFIG_TOP)     += duration.o
  17 //kbuild:lib-$(CONFIG_TIMEOUT) += duration.o
  18 //kbuild:lib-$(CONFIG_PING)    += duration.o
  19 //kbuild:lib-$(CONFIG_PING6)   += duration.o
  20 //kbuild:lib-$(CONFIG_WATCH)   += duration.o
  21
  22 #include "libbb.h"
  23
  24 static const struct suffix_mult duration_suffixes[] ALIGN_SUFFIX = {
  25         { "s", 1 },
  26         { "m", 60 },
  27         { "h", 60*60 },
  28         { "d", 24*60*60 },
  29         { "", 0 }
  30 };
  31
  32 #if ENABLE_FLOAT_DURATION
  33 duration_t FAST_FUNC parse_duration_str(char *str)
  34 {
  35         duration_t duration;
  36
  37         if (strchr(str, '.')) {
  38                 double d;
  39                 char *pp;
  40                 int len;
  41                 char sv;
  42
  43 # if ENABLE_LOCALE_SUPPORT
  44                 /* Undo busybox.c: on input, we want to use dot
  45                  * as fractional separator in strtod(),
  46                  * regardless of current locale
  47                  */
  48                 setlocale(LC_NUMERIC, "C");
  49 # endif
  50                 len = strspn(str, "0123456789.");
  51                 sv = str[len];
  52                 str[len] = '\0';
  53                 errno = 0;
  54                 d = strtod(str, &pp);
  55                 if (errno || *pp)
  56                         bb_show_usage();
  57                 str += len;
  58                 *str-- = sv;
  59                 sv = *str;
  60                 *str = '1';
  61                 duration = d * xatoul_sfx(str, duration_suffixes);
  62                 *str = sv;
  63         } else {
  64                 duration = xatoul_sfx(str, duration_suffixes);
  65         }
  66
  67         return duration;
  68 }
  69 void FAST_FUNC sleep_for_duration(duration_t duration)
  70 {
  71         struct timespec ts;
  72
  73         ts.tv_sec = MAXINT(typeof(ts.tv_sec));
  74         ts.tv_nsec = 0;
  75         if (duration >= 0 && duration < ts.tv_sec) {
  76                 ts.tv_sec = duration;
  77                 ts.tv_nsec = (duration - ts.tv_sec) * 1000000000;
  78         }
  79         /* NB: ENABLE_ASH_SLEEP requires that we do NOT loop on EINTR here:
  80          * otherwise, traps won't execute until we finish looping.
  81          */
  82         //do {
  83         //      errno = 0;
  84         //      nanosleep(&ts, &ts);
  85         //} while (errno == EINTR);
  86         nanosleep(&ts, &ts);
  87 }
  88 #else
  89 duration_t FAST_FUNC parse_duration_str(char *str)
  90 {
  91         return xatou_range_sfx(str, 0, UINT_MAX, duration_suffixes);
  92 }
  93 #endif