/usr/share/systemtap/tapset/linux
Edit: /usr/share/systemtap/tapset/linux/ctime.stp (5750B)
/* ctime.stp - Convert seconds to human readable date string.
*
* This code was adapted from the newlib mktm_r() and asctime_r()
* functions. In newlib, mktm_r.c states that it was adapted from
* tzcode maintained by Arthur David Olson. In newlib, asctime_r.c
* doesn't have any author/copyright information.
*
* Changes copyright (C) 2006-2016 Red Hat Inc.
*/
/**
* sfunction ctime - Convert seconds since epoch into human readable date/time string
*
* @epochsecs: Number of seconds since epoch (as returned by gettimeofday_s())
*
* Description: Takes an argument of seconds since the epoch as returned by
* gettimeofday_s(). Returns a string of the form
*
* "Wed Jun 30 21:49:08 1993"
*
* The string will always be exactly 24 characters. If the time would
* be unreasonable far in the past (before what can be represented
* with a 32 bit offset in seconds from the epoch) an error will occur
* (which can be avoided with try/catch). If the time would be
* unreasonable far in the future, an error will also occur.
*
* Note that the epoch (zero) corresponds to
*
* "Thu Jan 1 00:00:00 1970"
*
* The earliest full date given by ctime, corresponding to epochsecs
* -2147483648 is "Fri Dec 13 20:45:52 1901". The latest full date
* given by ctime, corresponding to epochsecs 2147483647 is
* "Tue Jan 19 03:14:07 2038".
*
* The abbreviations for the days of the week are ‘Sun’, ‘Mon’, ‘Tue’,
* ‘Wed’, ‘Thu’, ‘Fri’, and ‘Sat’. The abbreviations for the months
* are ‘Jan’, ‘Feb’, ‘Mar’, ‘Apr’, ‘May’, ‘Jun’, ‘Jul’, ‘Aug’, ‘Sep’,
* ‘Oct’, ‘Nov’, and ‘Dec’.
*
* Note that the real C library ctime() function puts a newline ('\n')
* character at the end of the string that this function does not.
* Also note that since the kernel has no concept of timezones, the
* returned time is always in GMT.
*/
function ctime:string(epochsecs:long)
%{ /* pure */
#define SECSPERMIN 60L
#define MINSPERHOUR 60L
#define HOURSPERDAY 24L
#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY (SECSPERHOUR * HOURSPERDAY)
#define DAYSPERWEEK 7
#define MONSPERYEAR 12
#define EPOCH_YEAR 1970
#define EPOCH_WDAY 4
#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
static const int mon_lengths[2][MONSPERYEAR] = {
{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
} ;
static const int year_lengths[2] = {
365,
366
} ;
static const char day_name[7][3] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char mon_name[12][3] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
long days, rem;
#if defined(STAPCONF_TIME32_OLD_H)
old_time32_t lcltime;
#else
time_t lcltime;
#endif
int yleap;
const int *ip;
int tm_sec; /* seconds */
int tm_min; /* minutes */
int tm_hour; /* hours */
int tm_mday; /* day of the month */
int tm_mon; /* month */
int tm_year; /* year */
int tm_wday; /* day of the week */
// Check that the numer of seconds is "reasonable".
// Otherwise (especially on 64bit machines) we will be spending
// way too much time calculating the correct year, month and
// day. Also we would like the returned string to always be 24 chars.
// So cap to what can be represented normally on a 32bit machine.
int64_t MAX_POS_SECS = 2147483647LL;
int64_t MIN_NEG_SECS = -2147483648LL;
if (STAP_ARG_epochsecs > MAX_POS_SECS)
{
#if STAP_COMPAT_VERSION <= STAP_VERSION(2,2)
strlcpy(STAP_RETVALUE, "far far in the future...", MAXSTRINGLEN);
#else
CONTEXT->last_error = "Time too far in the future to be converted";
#endif
return;
}
if (STAP_ARG_epochsecs < MIN_NEG_SECS)
{
#if STAP_COMPAT_VERSION <= STAP_VERSION(2,2)
strlcpy(STAP_RETVALUE, "a long, long time ago...", MAXSTRINGLEN);
#else
CONTEXT->last_error = "Time too far in the past to be converted";
#endif
return;
}
lcltime = STAP_ARG_epochsecs;
days = ((long)lcltime) / SECSPERDAY;
rem = ((long)lcltime) % SECSPERDAY;
while (rem < 0)
{
rem += SECSPERDAY;
--days;
}
while (rem >= SECSPERDAY)
{
rem -= SECSPERDAY;
++days;
}
/* compute hour, min, and sec */
tm_hour = (int) (rem / SECSPERHOUR);
rem %= SECSPERHOUR;
tm_min = (int) (rem / SECSPERMIN);
tm_sec = (int) (rem % SECSPERMIN);
/* compute day of week */
if ((tm_wday = ((EPOCH_WDAY + days) % DAYSPERWEEK)) < 0)
tm_wday += DAYSPERWEEK;
/* compute year & day of year */
tm_year = EPOCH_YEAR;
if (days >= 0)
{
for (;;)
{
yleap = isleap(tm_year);
if (days < year_lengths[yleap])
break;
tm_year++;
days -= year_lengths[yleap];
}
}
else
{
do
{
--tm_year;
yleap = isleap(tm_year);
days += year_lengths[yleap];
} while (days < 0);
}
ip = mon_lengths[yleap];
for (tm_mon = 0; days >= ip[tm_mon]; ++tm_mon)
days -= ip[tm_mon];
tm_mday = days + 1;
/*
* At this point we have all our information. Now we need to
* convert it to an ascii representation.
*/
snprintf (STAP_RETVALUE, MAXSTRINGLEN, "%.3s %.3s%3d %.2d:%.2d:%.2d %d",
day_name[tm_wday], mon_name[tm_mon],
tm_mday, tm_hour, tm_min,
tm_sec, tm_year);
%}
/**
* sfunction ctime - Convert seconds since epoch into human readable date/time string
*
* Without an argument, does the same as ctime(gettimeofday_s()).
*
*/
function ctime:string()
{
return ctime(gettimeofday_s())
}