]> pd.if.org Git - pdclib/blobdiff - functions/time/strftime.c
ISO week calculation.
[pdclib] / functions / time / strftime.c
index eb32a167c8eacc9f7e604fda31ba8b4e2de53d3f..77160619a293b9aa0d896e5c5b6a0d8afe142197 100644 (file)
 
 #ifndef REGTEST
 
-/* TODO: Alternative representations / numerals not supported. */
+/* TODO: Alternative representations / numerals not supported. Multibyte support missing. */
 
 /* This implementation's code is highly repetitive, but I did not really
    care for putting it into a number of macros / helper functions.
 */
 
+static int iso_week( const struct tm * timeptr )
+{
+    /* calculations below rely on Sunday == 7 */
+    int wday = timeptr->tm_wday;
+    if ( wday == 0 )
+    {
+        wday = 7;
+    }
+    /* https://en.wikipedia.org/wiki/ISO_week_date */
+    int week = ( timeptr->tm_yday - wday + 11 ) / 7;
+    if ( week == 53 )
+    {
+        /* date *may* belong to the *next* year, if:
+           * it is 31.12. and Monday - Wednesday
+           * it is 30.12. and Monday - Tuesday
+           * it is 29.12. and Monday
+           We can safely assume December...
+        */
+        if ( ( timeptr->tm_mday - wday ) > 27 )
+        {
+            week = 1;
+        }
+    }
+    else if ( week == 0 )
+    {
+        /* date *does* belong to *previous* year,
+           i.e. has week 52 *unless*...
+           * current year started on a Friday, or
+           * previous year is leap and this year
+             started on a Saturday.
+        */
+        int firstday = timeptr->tm_wday - ( timeptr->tm_yday % 7 );
+        if ( firstday < 0 )
+        {
+            firstday += 7;
+        }
+        if ( ( firstday == 5 ) || ( _PDCLIB_is_leap( timeptr->tm_year - 1 ) && firstday == 6 ) )
+        {
+            week = 53;
+        }
+        else
+        {
+            week = 52;
+        }
+    }
+    return week;
+}
+
+static int sprints( char * _PDCLIB_restrict dest, const char * _PDCLIB_restrict src, size_t maxsize, size_t * rc )
+{
+    size_t len = strlen( src );
+    if ( *rc < ( maxsize - len ) )
+    {
+        strcpy( dest + *rc, src );
+        *rc += len;
+        return 1;
+    }
+    else
+    {
+        return 0;
+    }
+}
+
 size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB_restrict format, const struct tm * _PDCLIB_restrict timeptr )
 {
     size_t rc = 0;
@@ -25,7 +88,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
     {
         if ( *format != '%' )
         {
-            if ( ( *s++ = *format++ ) == '\0' )
+            if ( ( s[rc] = *format++ ) == '\0' )
             {
                 return rc;
             }
@@ -52,14 +115,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'a':
                     {
                         /* tm_wday abbreviated */
-                        const char * day = _PDCLIB_lconv.day_name_abbr[ timeptr->tm_wday ];
-                        size_t len = strlen( day );
-                        if ( rc < ( maxsize - len ) )
-                        {
-                            strcpy( s, day );
-                            rc += len;
-                        }
-                        else
+                        if ( ! sprints( s, _PDCLIB_lconv.day_name_abbr[ timeptr->tm_wday ], maxsize, &rc ) )
                         {
                             return 0;
                         }
@@ -68,14 +124,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'A':
                     {
                         /* tm_wday full */
-                        const char * day = _PDCLIB_lconv.day_name_full[ timeptr->tm_wday ];
-                        size_t len = strlen( day );
-                        if ( rc < ( maxsize - len ) )
-                        {
-                            strcpy( s, day );
-                            rc += len;
-                        }
-                        else
+                        if ( ! sprints( s, _PDCLIB_lconv.day_name_full[ timeptr->tm_wday ], maxsize, &rc ) )
                         {
                             return 0;
                         }
@@ -85,14 +134,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'h':
                     {
                         /* tm_mon abbreviated */
-                        const char * month = _PDCLIB_lconv.month_name_abbr[ timeptr->tm_mon ];
-                        size_t len = strlen( month );
-                        if ( rc < ( maxsize - len ) )
-                        {
-                            strcpy( s, month );
-                            rc += len;
-                        }
-                        else
+                        if ( ! sprints( s, _PDCLIB_lconv.month_name_abbr[ timeptr->tm_mon ], maxsize, &rc ) )
                         {
                             return 0;
                         }
@@ -101,14 +143,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'B':
                     {
                         /* tm_mon full */
-                        const char * month = _PDCLIB_lconv.month_name_full[ timeptr->tm_mon ];
-                        size_t len = strlen( month );
-                        if ( rc < ( maxsize - len ) )
-                        {
-                            strcpy( s, month );
-                            rc += len;
-                        }
-                        else
+                        if ( ! sprints( s, _PDCLIB_lconv.month_name_full[ timeptr->tm_mon ], maxsize, &rc ) )
                         {
                             return 0;
                         }
@@ -118,7 +153,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                     {
                         /* locale's date / time representation, %a %b %e %T %Y for C locale */
                         /* 'E' for locale's alternative representation */
-                        size_t count = strftime( s, maxsize - rc, _PDCLIB_lconv.date_time_format, timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.date_time_format, timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -135,10 +170,9 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         /* 'E' for base year (period) in locale's alternative representation */
                         if ( rc < ( maxsize - 2 ) )
                         {
-                            div_t period = div( ( timeptr->tm_year / 100 ), 10 );
-                            *s++ = '0' + period.quot;
-                            *s++ = '0' + period.rem;
-                            rc += 2;
+                            div_t period = div( ( ( timeptr->tm_year + 1900 ) / 100 ), 10 );
+                            s[rc++] = '0' + period.quot;
+                            s[rc++] = '0' + period.rem;
                         }
                         else
                         {
@@ -153,9 +187,8 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         if ( rc < ( maxsize - 2 ) )
                         {
                             div_t day = div( timeptr->tm_mday, 10 );
-                            *s++ = '0' + day.quot;
-                            *s++ = '0' + day.rem;
-                            rc += 2;
+                            s[rc++] = '0' + day.quot;
+                            s[rc++] = '0' + day.rem;
                         }
                         else
                         {
@@ -166,7 +199,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'D':
                     {
                         /* %m/%d/%y */
-                        size_t count = strftime( s, maxsize - rc, "%m/%d/%y", timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, "%m/%d/%y", timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -184,9 +217,8 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         if ( rc < ( maxsize - 2 ) )
                         {
                             div_t day = div( timeptr->tm_mday, 10 );
-                            *s++ = ( day.quot > 0 ) ? '0' + day.quot : ' ';
-                            *s++ = '0' + day.rem;
-                            rc += 2;
+                            s[rc++] = ( day.quot > 0 ) ? '0' + day.quot : ' ';
+                            s[rc++] = '0' + day.rem;
                         }
                         else
                         {
@@ -197,7 +229,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'F':
                     {
                         /* %Y-%m-%d */
-                        size_t count = strftime( s, maxsize - rc, "%Y-%m-%d", timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, "%Y-%m-%d", timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -211,13 +243,56 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'g':
                     {
                         /* last 2 digits of the week-based year as decimal (00-99) */
-                        /* TODO: 'g' */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            int week = iso_week( timeptr );
+                            int bias = 0;
+                            if ( week >= 52 && timeptr->tm_mon == 0 )
+                            {
+                                --bias;
+                            }
+                            else if ( week == 1 && timeptr->tm_mon == 11 )
+                            {
+                                ++bias;
+                            }
+                            div_t year = div( timeptr->tm_year % 100 + bias, 10 );
+                            s[rc++] = '0' + year.quot;
+                            s[rc++] = '0' + year.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
                         break;
                     }
                 case 'G':
                     {
                         /* week-based year as decimal (e.g. 1997) */
-                        /* TODO: 'G' */
+                        if ( rc < ( maxsize - 4 ) )
+                        {
+                            int week = iso_week( timeptr );
+                            int year = timeptr->tm_year + 1900;
+                            if ( week >= 52 && timeptr->tm_mon == 0 )
+                            {
+                                --year;
+                            }
+                            else if ( week == 1 && timeptr->tm_mon == 11 )
+                            {
+                                ++year;
+                            }
+                            for ( int i = 3; i >= 0; --i )
+                            {
+                                div_t digit = div( year, 10 );
+                                s[ rc + i ] = '0' + digit.rem;
+                                year = digit.quot;
+                            }
+
+                            rc += 4;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
                         break;
                     }
                 case 'H':
@@ -227,9 +302,8 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         if ( rc < ( maxsize - 2 ) )
                         {
                             div_t hour = div( timeptr->tm_hour, 10 );
-                            *s++ = '0' + hour.quot;
-                            *s++ = '0' + hour.rem;
-                            rc += 2;
+                            s[rc++] = '0' + hour.quot;
+                            s[rc++] = '0' + hour.rem;
                         }
                         else
                         {
@@ -243,10 +317,9 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         /* 'O' for locale's alternative numeric symbols */
                         if ( rc < ( maxsize - 2 ) )
                         {
-                            div_t hour = div( ( timeptr->tm_hour + 1 ) % 12, 10 );
-                            *s++ = '0' + hour.quot;
-                            *s++ = '0' + hour.rem;
-                            rc += 2;
+                            div_t hour = div( ( timeptr->tm_hour + 11 ) % 12 + 1, 10 );
+                            s[rc++] = '0' + hour.quot;
+                            s[rc++] = '0' + hour.rem;
                         }
                         else
                         {
@@ -259,11 +332,10 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         /* tm_yday as decimal (001-366) */
                         if ( rc < ( maxsize - 3 ) )
                         {
-                            div_t yday = div( timeptr->tm_yday, 100 );
-                            *s++ = '0' + yday.quot;
-                            *s++ = '0' + yday.rem / 10;
-                            *s++ = '0' + yday.rem % 10;
-                            rc += 3;
+                            div_t yday = div( timeptr->tm_yday + 1, 100 );
+                            s[rc++] = '0' + yday.quot;
+                            s[rc++] = '0' + yday.rem / 10;
+                            s[rc++] = '0' + yday.rem % 10;
                         }
                         else
                         {
@@ -278,9 +350,8 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         if ( rc < ( maxsize - 2 ) )
                         {
                             div_t mon = div( timeptr->tm_mon + 1, 10 );
-                            *s++ = '0' + mon.quot;
-                            *s++ = '0' + mon.rem;
-                            rc += 2;
+                            s[rc++] = '0' + mon.quot;
+                            s[rc++] = '0' + mon.rem;
                         }
                         else
                         {
@@ -294,10 +365,9 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         /* 'O' for locale's alternative numeric symbols */
                         if ( rc < ( maxsize - 2 ) )
                         {
-                            div_t min = div( timeptr->tm_min + 1, 10 );
-                            *s++ = '0' + min.quot;
-                            *s++ = '0' + min.rem;
-                            rc += 2;
+                            div_t min = div( timeptr->tm_min, 10 );
+                            s[rc++] = '0' + min.quot;
+                            s[rc++] = '0' + min.rem;
                         }
                         else
                         {
@@ -308,8 +378,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'n':
                     {
                         /* newline */
-                        *s++ = '\n';
-                        ++rc;
+                        s[rc++] = '\n';
                         break;
                     }
                 case 'p':
@@ -319,7 +388,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         size_t len = strlen( designation );
                         if ( rc < ( maxsize - len ) )
                         {
-                            strcpy( s, designation );
+                            strcpy( s + rc, designation );
                             rc += len;
                         }
                         else
@@ -331,7 +400,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'r':
                     {
                         /* tm_hour / tm_min / tm_sec as locale's 12-hour clock time, %I:%M:%S %p for C locale */
-                        size_t count = strftime( s, maxsize - rc, _PDCLIB_lconv.time_format_12h, timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.time_format_12h, timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -345,7 +414,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 'R':
                     {
                         /* %H:%M */
-                        size_t count = strftime( s, maxsize - rc, "%H:%M", timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, "%H:%M", timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -362,10 +431,9 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         /* 'O' for locale's alternative numeric symbols */
                         if ( rc < ( maxsize - 2 ) )
                         {
-                            div_t sec = div( timeptr->tm_sec + 1, 10 );
-                            *s++ = '0' + sec.quot;
-                            *s++ = '0' + sec.rem;
-                            rc += 2;
+                            div_t sec = div( timeptr->tm_sec, 10 );
+                            s[rc++] = '0' + sec.quot;
+                            s[rc++] = '0' + sec.rem;
                         }
                         else
                         {
@@ -376,14 +444,13 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case 't':
                     {
                         /* tabulator */
-                        *s++ = '\t';
-                        ++rc;
+                        s[rc++] = '\t';
                         break;
                     }
                 case 'T':
                     {
                         /* %H:%M:%S */
-                        size_t count = strftime( s, maxsize - rc, "%H:%M:%S", timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, "%H:%M:%S", timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -398,8 +465,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                     {
                         /* tm_wday as decimal (1-7) with Monday == 1 */
                         /* 'O' for locale's alternative numeric symbols */
-                        *s++ = ( timeptr->tm_wday == 0 ) ? '7' : '0' + timeptr->tm_wday;
-                        ++rc;
+                        s[rc++] = ( timeptr->tm_wday == 0 ) ? '7' : '0' + timeptr->tm_wday;
                         break;
                     }
                 case 'U':
@@ -411,17 +477,25 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                     }
                 case 'V':
                     {
-                        /* week number as decimal (01-53) */
+                        /* ISO week number as decimal (01-53) */
                         /* 'O' for locale's alternative numeric symbols */
-                        /* TODO: 'V' */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t week = div( iso_week( timeptr ), 10 );
+                            s[rc++] = '0' + week.quot;
+                            s[rc++] = '0' + week.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
                         break;
                     }
                 case 'w':
                     {
                         /* tm_wday as decimal number (0-6) with Sunday == 0 */
                         /* 'O' for locale's alternative numeric symbols */
-                        *s++ = '0' + timeptr->tm_wday;
-                        ++rc;
+                        s[rc++] = '0' + timeptr->tm_wday;
                         break;
                     }
                 case 'W':
@@ -435,7 +509,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                     {
                         /* locale's date representation, %m/%d/%y for C locale */
                         /* 'E' for locale's alternative representation */
-                        size_t count = strftime( s, maxsize - rc, _PDCLIB_lconv.date_format, timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.date_format, timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -450,7 +524,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                     {
                         /* locale's time representation, %T for C locale */
                         /* 'E' for locale's alternative representation */
-                        size_t count = strftime( s, maxsize - rc, _PDCLIB_lconv.time_format, timeptr );
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.time_format, timeptr );
                         if ( count == 0 )
                         {
                             return 0;
@@ -469,9 +543,8 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         if ( rc < ( maxsize - 2 ) )
                         {
                             div_t year = div( ( timeptr->tm_year % 100 ), 10 );
-                            *s++ = '0' + year.quot;
-                            *s++ = '0' + year.rem;
-                            rc += 2;
+                            s[rc++] = '0' + year.quot;
+                            s[rc++] = '0' + year.rem;
                         }
                         else
                         {
@@ -485,12 +558,12 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                         /* 'E' for locale's alternative representation */
                         if ( rc < ( maxsize - 4 ) )
                         {
-                            int year = timeptr->tm_year;
+                            int year = timeptr->tm_year + 1900;
 
                             for ( int i = 3; i >= 0; --i )
                             {
                                 div_t digit = div( year, 10 );
-                                s[i] = '0' + digit.rem;
+                                s[ rc + i ] = '0' + digit.rem;
                                 year = digit.quot;
                             }
 
@@ -517,8 +590,7 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
                 case '%':
                     {
                         /* '%' character */
-                        *s++ = '%';
-                        ++rc;
+                        s[rc++] = '%';
                         break;
                     }
             }
@@ -534,9 +606,134 @@ size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB
 
 #include "_PDCLIB_test.h"
 
+#define MKTIME( tm, sec, min, hour, day, month, year, wday, yday ) tm.tm_sec = sec; tm.tm_min = min; tm.tm_hour = hour; tm.tm_mday = day; tm.tm_mon = month; tm.tm_year = year; tm.tm_wday = wday; tm.tm_yday = yday; tm.tm_isdst = -1;
+
 int main( void )
 {
-    TESTCASE( NO_TESTDRIVER );
+    char buffer[100];
+    /* Basic functionality */
+    struct tm timeptr;
+    MKTIME( timeptr, 59, 30, 12, 1, 9, 72, 0, 274 );
+    TESTCASE( strftime( buffer, 100, "%a ", &timeptr ) == 4 );
+    TESTCASE( strcmp( buffer, "Sun " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%A ", &timeptr ) == 7 );
+    TESTCASE( strcmp( buffer, "Sunday " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%b ", &timeptr ) == 4 );
+    TESTCASE( strcmp( buffer, "Oct " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%h ", &timeptr ) == 4 );
+    TESTCASE( strcmp( buffer, "Oct " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%B ", &timeptr ) == 8 );
+    TESTCASE( strcmp( buffer, "October " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%c ", &timeptr ) == 25 );
+    TESTCASE( strcmp( buffer, "Sun Oct  1 12:30:59 1972 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%C ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "19 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%d ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "01 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%D ", &timeptr ) == 9 );
+    TESTCASE( strcmp( buffer, "10/01/72 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%e ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, " 1 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%F ", &timeptr ) == 11 );
+    TESTCASE( strcmp( buffer, "1972-10-01 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%H ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "12 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%I ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "12 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%j ", &timeptr ) == 4 );
+    TESTCASE( strcmp( buffer, "275 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%m ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "10 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%M ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "30 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%p ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "PM " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%r ", &timeptr ) == 12 );
+    TESTCASE( strcmp( buffer, "12:30:59 PM " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%R ", &timeptr ) == 6 );
+    TESTCASE( strcmp( buffer, "12:30 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%S ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "59 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%T ", &timeptr ) == 9 );
+    TESTCASE( strcmp( buffer, "12:30:59 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%u ", &timeptr ) == 2 );
+    TESTCASE( strcmp( buffer, "7 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%w ", &timeptr ) == 2 );
+    TESTCASE( strcmp( buffer, "0 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%x ", &timeptr ) == 9 );
+    TESTCASE( strcmp( buffer, "10/01/72 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%X ", &timeptr ) == 9 );
+    TESTCASE( strcmp( buffer, "12:30:59 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%y ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "72 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%Y ", &timeptr ) == 5 );
+    TESTCASE( strcmp( buffer, "1972 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%% ", &timeptr ) == 2 );
+    TESTCASE( strcmp( buffer, "% " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%n ", &timeptr ) == 2 );
+    TESTCASE( strcmp( buffer, "\n " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%t ", &timeptr ) == 2 );
+    TESTCASE( strcmp( buffer, "\t " ) == 0 );
+    /* ISO week calculation */
+    MKTIME( timeptr, 0, 0, 0, 27, 11, 3, 0, 360 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "52 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 28, 11, 3, 1, 361 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "53 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 31, 11, 3, 4, 364 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "53 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 1, 0, 4, 5, 0 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "53 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 3, 0, 4, 0, 2 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "53 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%g ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "03 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%G ", &timeptr ) == 5 );
+    TESTCASE( strcmp( buffer, "1903 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 4, 0, 4, 1, 3 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "01 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%g ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "04 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%G ", &timeptr ) == 5 );
+    TESTCASE( strcmp( buffer, "1904 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 1, 0, 5, 0, 0 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "52 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%g ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "04 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%G ", &timeptr ) == 5 );
+    TESTCASE( strcmp( buffer, "1904 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 24, 11, 100, 0, 358 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "51 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 25, 11, 100, 1, 359 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "52 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 31, 11, 100, 0, 365 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "52 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%g ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "00 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%G ", &timeptr ) == 5 );
+    TESTCASE( strcmp( buffer, "2000 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 1, 0, 101, 1, 0 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "01 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%g ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "01 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%G ", &timeptr ) == 5 );
+    TESTCASE( strcmp( buffer, "2001 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 7, 0, 101, 7, 6 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "01 " ) == 0 );
+    MKTIME( timeptr, 0, 0, 0, 8, 0, 101, 1, 7 );
+    TESTCASE( strftime( buffer, 100, "%V ", &timeptr ) == 3 );
+    TESTCASE( strcmp( buffer, "02 " ) == 0 );
     return TEST_RESULTS;
 }