Mail Archives: cygwin/2015/10/22/03:04:46
Brian Inglis <Brian.Inglis <at> SystematicSw.ab.ca> writes:
>
> Don Harrop <don <at> effx.us> writes:
> > Bash outputs no value when using it's built in method of printing an
> > "epoch" timestamp.
> > BashCommandLine#: printf '%(%s)T' -1
>
> bash printf depends on underlying strftime in newlib, which does not support
> %s, as it is conditional on _WANT_C99_TIME_FORMATS being defined, and that
> is presumably not defined in the config, as %s is not shown in man strftime.
> Workaround for now is use
> date +%s
> for current time, and
> date -d $(printf '%(%T)T' -2) +%s
> for shell invocation time.
> %s, as it is conditional on _WANT_C99_TIME_FORMATS being defined, and that
Wrong! Misread the code, strftime %s is not supported!
STC and suggested patch appended (posting from gmane), compiles, but can't
build STC as ld fails with undef refs, and I don't know all the correct
LD..., -L and -l incantations. Email me for original files.
/* newlib/time/strftime.c %s format STC */
#include <stdio.h>
#include <time.h>
int main( int argc, char **argv) {
char ss[BUFSIZ] = "";
time_t tt = time( NULL );
struct tm *tp = gmtime( &tt );
tt = mktime( tp );
size_t st = strftime( ss, sizeof ss, "%s", tp);
int rc = puts( ss );
st = strftime( ss, sizeof ss, "%T", tp);
rc = puts( ss );
return rc;
}
--- 8< ---
2015-10-12 Brian Inglis <Brian DOT Inglis AT SystematicSw DOT ab DOT ca>
* newlib/time/strftime.c (__strftime): add support for %s (seconds from Unix
epoch)
--- a/newlib/time/strftime.c 2015-08-20 03:39:24.000000000 -0600
+++ b/newlib/time/strftime.c 2015-10-21 20:15:22.367453000 -0600
@@ -166,6 +166,10 @@ notations, the result is an empty string
o %R
The 24-hour time, to the minute. Equivalent to "%H:%M". [tm_min, tm_hour]
+o %s
+The time elapsed, in seconds, since the start of the Unix epoch at
+1970-01-01 00:00:00 UTC.
+
o %S
The second, formatted with two digits (from `<<00>>' to `<<60>>'). The
value 60 accounts for the occasional leap second. [tm_sec]
@@ -1109,6 +1113,74 @@ recurse:
tim_p->tm_hour, tim_p->tm_min);
CHECK_LENGTH ();
break;
+ case CQ('s'):
+/*
+ * From:
+ * The Open Group Base Specifications Issue 7
+ * IEEE Std 1003.1, 2013 Edition
+ * Copyright (c) 2001-2013 The IEEE and The Open Group
+ * XBD Base Definitions
+ * 4. General Concepts
+ * 4.15 Seconds Since the Epoch
+ * A value that approximates the number of seconds that have elapsed since the
+ * Epoch. A Coordinated Universal Time name (specified in terms of seconds
+ * (tm_sec), minutes (tm_min), hours (tm_hour), days since January 1 of the
year
+ * (tm_yday), and calendar year minus 1900 (tm_year)) is related to a time
+ * represented as seconds since the Epoch, according to the expression below.
+ * If the year is <1970 or the value is negative, the relationship is
undefined.
+ * If the year is >=1970 and the value is non-negative, the value is
related to a
+ * Coordinated Universal Time name according to the C-language expression,
where
+ * tm_sec, tm_min, tm_hour, tm_yday, and tm_year are all integer types:
+ * tm_sec + tm_min*60 + tm_hour*3600 + tm_yday*86400 +
+ * (tm_year-70)*31536000 + ((tm_year-69)/4)*86400 -
+ * ((tm_year-1)/100)*86400 + ((tm_year+299)/400)*86400
+ * OR
+ * ((((tm_year-69)/4 - (tm_year-1)/100 + (tm_year+299)/400 +
+ * (tm_year-70)*365 + tm_yday)*24 + tm_hour)*60 + tm_min)*60 + tm_sec
+ */
+/* modified from %z case by hoisting offset outside if block and
initializing */
+ {
+ long offset; /* offset < 0 => W of GMT, > 0 => E of GMT:
+ offset = 0; subtract to get UTC */
+
+ if (tim_p->tm_isdst >= 0)
+ {
+ TZ_LOCK;
+ if (!tzset_called)
+ {
+ _tzset_unlocked ();
+ tzset_called = 1;
+ }
+
+#if defined (__CYGWIN__)
+ /* Cygwin must check if the application has been built with or
+ without the extra tm members for backward compatibility, and
+ then use either that or the old method fetching from tzinfo.
+ Rather than pulling in the version check infrastructure, we
+ just call a Cygwin function. */
+ extern long __cygwin_gettzoffset (const struct tm *tmp);
+ offset = __cygwin_gettzoffset (tim_p);
+#elif defined (__TM_GMTOFF)
+ offset = tim_p->__TM_GMTOFF;
+#else
+ __tzinfo_type *tz = __gettzinfo ();
+ /* The sign of this is exactly opposite the envvar TZ. We
+ could directly use the global _timezone for tm_isdst==0,
+ but have to use __tzrule for daylight savings. */
+ offset = -tz->__tzrule[tim_p->tm_isdst > 0].offset;
+#endif
+ TZ_UNLOCK;
+ }
+ len = snprintf (&s[count], maxsize - count, CQ("%lld"),
+ (((((long long)tim_p->tm_year - 69)/4
+ - (tim_p->tm_year - 1)/100
+ + (tim_p->tm_year + 299)/400
+ + (tim_p->tm_year - 70)*365 + tim_p->tm_yday)*24
+ + tim_p->tm_hour)*60 + tim_p->tm_min)*60
+ + tim_p->tm_sec - offset);
+ CHECK_LENGTH ();
+ }
+ break;
case CQ('S'):
#ifdef _WANT_C99_TIME_FORMATS
if (alt != CQ('O') || !*alt_digits
@@ -1442,6 +1514,7 @@ const struct test Vec0[] = {
{ CQ("%p"), 2+1, EXP(CQ("AM")) },
{ CQ("%r"), 11+1, EXP(CQ("09:53:47 AM")) },
{ CQ("%R"), 5+1, EXP(CQ("09:53")) },
+ { CQ("%s"), 2+1, EXP(CQ("1230648827")) },
{ CQ("%S"), 2+1, EXP(CQ("47")) },
{ CQ("%t"), 1+1, EXP(CQ("\t")) },
{ CQ("%T"), 8+1, EXP(CQ("09:53:47")) },
--
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