diff options
Diffstat (limited to 'libc/misc/time/tm_conv.c')
| -rw-r--r-- | libc/misc/time/tm_conv.c | 207 |
1 files changed, 101 insertions, 106 deletions
diff --git a/libc/misc/time/tm_conv.c b/libc/misc/time/tm_conv.c index ec0073294..d345f7528 100644 --- a/libc/misc/time/tm_conv.c +++ b/libc/misc/time/tm_conv.c @@ -5,63 +5,64 @@ /* This is a translation from ALGOL in Collected Algorithms of CACM. */ /* Copied from Algorithm 199, Author: Robert G. Tantzen */ -void -__tm_conv(tmbuf, timep, offset) +void __tm_conv(tmbuf, timep, offset) struct tm *tmbuf; time_t *timep; time_t offset; { -static int moffset[] = - {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}; - - long s; - long j, d, m, y; - - offset += *timep; - - tmbuf->tm_isdst = 0; /* Someone else can set this */ - - j = offset / 86400L + 719469; - s = offset % 86400L; - - if( s < 0 ) { s += 86400L; j--; } - - tmbuf->tm_sec = s % 60; - tmbuf->tm_min = (s / 60) % 60; - tmbuf->tm_hour = s / 3600; - - tmbuf->tm_wday = (j+2) % 7; - - /* - * Julian date converter. Takes a julian date (the number of days since - * some distant epoch or other), and fills tmbuf. - */ - - y = (4L * j - 1L) / 146097L; - j = 4L * j - 1L - 146097L * y; - d = j / 4L; - j = (4L * d + 3L) / 1461L; - d = 4L * d + 3L - 1461L * j; - d = (d + 4L) / 4L; - m = (5L * d - 3L) / 153L; - d = 5L * d - 3 - 153L * m; - d = (d + 5L) / 5L; - y = 100L * y + j; - if (m < 10) - m += 2; - else - { - m -= 10; - ++y; - } - - tmbuf->tm_year = y - 1900; - tmbuf->tm_mon = m; - tmbuf->tm_mday = d; - - tmbuf->tm_yday = d + moffset[m]; - if (m > 1 && ((y) % 4 == 0 && ((y) % 100 != 0 || (y) % 400 == 0))) - tmbuf->tm_yday++; + static int moffset[] = + { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; + + long s; + long j, d, m, y; + + offset += *timep; + + tmbuf->tm_isdst = 0; /* Someone else can set this */ + + j = offset / 86400L + 719469; + s = offset % 86400L; + + if (s < 0) { + s += 86400L; + j--; + } + + tmbuf->tm_sec = s % 60; + tmbuf->tm_min = (s / 60) % 60; + tmbuf->tm_hour = s / 3600; + + tmbuf->tm_wday = (j + 2) % 7; + + /* + * Julian date converter. Takes a julian date (the number of days since + * some distant epoch or other), and fills tmbuf. + */ + + y = (4L * j - 1L) / 146097L; + j = 4L * j - 1L - 146097L * y; + d = j / 4L; + j = (4L * d + 3L) / 1461L; + d = 4L * d + 3L - 1461L * j; + d = (d + 4L) / 4L; + m = (5L * d - 3L) / 153L; + d = 5L * d - 3 - 153L * m; + d = (d + 5L) / 5L; + y = 100L * y + j; + if (m < 10) + m += 2; + else { + m -= 10; + ++y; + } + + tmbuf->tm_year = y - 1900; + tmbuf->tm_mon = m; + tmbuf->tm_mday = d; + + tmbuf->tm_yday = d + moffset[m]; + if (m > 1 && ((y) % 4 == 0 && ((y) % 100 != 0 || (y) % 400 == 0))) + tmbuf->tm_yday++; } #else @@ -74,65 +75,59 @@ static int moffset[] = #include <time.h> -static const unsigned short int __mon_lengths[2][12] = - { - /* Normal years. */ - { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, - /* Leap years. */ - { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } - }; +static const unsigned short int __mon_lengths[2][12] = { + /* Normal years. */ + {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, + /* Leap years. */ + {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} +}; -void -__tm_conv(tmbuf, t, offset) +void __tm_conv(tmbuf, t, offset) struct tm *tmbuf; time_t *t; time_t offset; { - long days, rem; - register int y; - register const unsigned short int *ip; - - days = *t / SECS_PER_DAY; - rem = *t % SECS_PER_DAY; - rem += offset; - while (rem < 0) - { - rem += SECS_PER_DAY; - --days; - } - while (rem >= SECS_PER_DAY) - { - rem -= SECS_PER_DAY; - ++days; - } - tmbuf->tm_hour = rem / SECS_PER_HOUR; - rem %= SECS_PER_HOUR; - tmbuf->tm_min = rem / 60; - tmbuf->tm_sec = rem % 60; - /* January 1, 1970 was a Thursday. */ - tmbuf->tm_wday = (4 + days) % 7; - if (tmbuf->tm_wday < 0) - tmbuf->tm_wday += 7; - y = 1970; - while (days >= (rem = __isleap(y) ? 366 : 365)) - { - ++y; - days -= rem; - } - while (days < 0) - { - --y; - days += __isleap(y) ? 366 : 365; - } - tmbuf->tm_year = y - 1900; - tmbuf->tm_yday = days; - ip = __mon_lengths[__isleap(y)]; - for (y = 0; days >= ip[y]; ++y) - days -= ip[y]; - tmbuf->tm_mon = y; - tmbuf->tm_mday = days + 1; - tmbuf->tm_isdst = -1; + long days, rem; + register int y; + register const unsigned short int *ip; + + days = *t / SECS_PER_DAY; + rem = *t % SECS_PER_DAY; + rem += offset; + while (rem < 0) { + rem += SECS_PER_DAY; + --days; + } + while (rem >= SECS_PER_DAY) { + rem -= SECS_PER_DAY; + ++days; + } + tmbuf->tm_hour = rem / SECS_PER_HOUR; + rem %= SECS_PER_HOUR; + tmbuf->tm_min = rem / 60; + tmbuf->tm_sec = rem % 60; + /* January 1, 1970 was a Thursday. */ + tmbuf->tm_wday = (4 + days) % 7; + if (tmbuf->tm_wday < 0) + tmbuf->tm_wday += 7; + y = 1970; + while (days >= (rem = __isleap(y) ? 366 : 365)) { + ++y; + days -= rem; + } + while (days < 0) { + --y; + days += __isleap(y) ? 366 : 365; + } + tmbuf->tm_year = y - 1900; + tmbuf->tm_yday = days; + ip = __mon_lengths[__isleap(y)]; + for (y = 0; days >= ip[y]; ++y) + days -= ip[y]; + tmbuf->tm_mon = y; + tmbuf->tm_mday = days + 1; + tmbuf->tm_isdst = -1; } #endif |