]> pd.if.org Git - pdclib/blobdiff - functions/time/strftime.c
Improved strftime().
[pdclib] / functions / time / strftime.c
index 2402f8cb82b8963e9c9ddb856142ab09b71c5d56..92e6062fe43ecb6a1007b5af6539905d82c42a5f 100644 (file)
 */
 
 #include <time.h>
+#include <stdlib.h>
+#include <locale.h>
+#include <string.h>
 
 #ifndef REGTEST
 
-size_t strftime( char * restrict s, size_t maxsize, const char * restrict format, const struct tm * restrict timeptr )
+/* 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.
+*/
+
+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;
+
+    while ( rc < maxsize )
+    {
+        if ( *format != '%' )
+        {
+            if ( ( s[rc] = *format++ ) == '\0' )
+            {
+                return rc;
+            }
+            else
+            {
+                ++rc;
+            }
+        }
+        else
+        {
+            /* char flag = 0; */
+            switch ( *++format )
+            {
+                case 'E':
+                case 'O':
+                    /* flag = *format++; */
+                    break;
+                default:
+                    /* EMPTY */
+                    break;
+            }
+            switch( *format++ )
+            {
+                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 + rc, day );
+                            rc += len;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                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 + rc, day );
+                            rc += len;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'b':
+                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 + rc, month );
+                            rc += len;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                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 + rc, month );
+                            rc += len;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'c':
+                    {
+                        /* locale's date / time representation, %a %b %e %T %Y for C locale */
+                        /* 'E' for locale's alternative representation */
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.date_time_format, timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'C':
+                    {
+                        /* tm_year divided by 100, truncated to decimal (00-99) */
+                        /* 'E' for base year (period) in locale's alternative representation */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t period = div( ( ( timeptr->tm_year + 1900 ) / 100 ), 10 );
+                            s[rc++] = '0' + period.quot;
+                            s[rc++] = '0' + period.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'd':
+                    {
+                        /* tm_mday as decimal (01-31) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t day = div( timeptr->tm_mday, 10 );
+                            s[rc++] = '0' + day.quot;
+                            s[rc++] = '0' + day.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'D':
+                    {
+                        /* %m/%d/%y */
+                        size_t count = strftime( s + rc, maxsize - rc, "%m/%d/%y", timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'e':
+                    {
+                        /* tm_mday as decimal ( 1-31) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t day = div( timeptr->tm_mday, 10 );
+                            s[rc++] = ( day.quot > 0 ) ? '0' + day.quot : ' ';
+                            s[rc++] = '0' + day.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'F':
+                    {
+                        /* %Y-%m-%d */
+                        size_t count = strftime( s + rc, maxsize - rc, "%Y-%m-%d", timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'g':
+                    {
+                        /* last 2 digits of the week-based year as decimal (00-99) */
+                        /* TODO: 'g' */
+                        break;
+                    }
+                case 'G':
+                    {
+                        /* week-based year as decimal (e.g. 1997) */
+                        /* TODO: 'G' */
+                        break;
+                    }
+                case 'H':
+                    {
+                        /* tm_hour as 24h decimal (00-23) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t hour = div( timeptr->tm_hour, 10 );
+                            s[rc++] = '0' + hour.quot;
+                            s[rc++] = '0' + hour.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'I':
+                    {
+                        /* tm_hour as 12h decimal (01-12) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t hour = div( ( timeptr->tm_hour + 1 ) % 12, 10 );
+                            s[rc++] = '0' + hour.quot;
+                            s[rc++] = '0' + hour.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'j':
+                    {
+                        /* tm_yday as decimal (001-366) */
+                        if ( rc < ( maxsize - 3 ) )
+                        {
+                            div_t yday = div( timeptr->tm_yday, 100 );
+                            s[rc++] = '0' + yday.quot;
+                            s[rc++] = '0' + yday.rem / 10;
+                            s[rc++] = '0' + yday.rem % 10;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'm':
+                    {
+                        /* tm_mon as decimal (01-12) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t mon = div( timeptr->tm_mon + 1, 10 );
+                            s[rc++] = '0' + mon.quot;
+                            s[rc++] = '0' + mon.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'M':
+                    {
+                        /* tm_min as decimal (00-59) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t min = div( timeptr->tm_min, 10 );
+                            s[rc++] = '0' + min.quot;
+                            s[rc++] = '0' + min.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'n':
+                    {
+                        /* newline */
+                        s[rc++] = '\n';
+                        break;
+                    }
+                case 'p':
+                    {
+                        /* tm_hour locale's AM/PM designations */
+                        const char * designation = _PDCLIB_lconv.am_pm[ timeptr->tm_hour > 11 ];
+                        size_t len = strlen( designation );
+                        if ( rc < ( maxsize - len ) )
+                        {
+                            strcpy( s + rc, designation );
+                            rc += len;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                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 + rc, maxsize - rc, _PDCLIB_lconv.time_format_12h, timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'R':
+                    {
+                        /* %H:%M */
+                        size_t count = strftime( s + rc, maxsize - rc, "%H:%M", timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'S':
+                    {
+                        /* tm_sec as decimal (00-60) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t sec = div( timeptr->tm_sec, 10 );
+                            s[rc++] = '0' + sec.quot;
+                            s[rc++] = '0' + sec.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 't':
+                    {
+                        /* tabulator */
+                        s[rc++] = '\t';
+                        break;
+                    }
+                case 'T':
+                    {
+                        /* %H:%M:%S */
+                        size_t count = strftime( s + rc, maxsize - rc, "%H:%M:%S", timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'u':
+                    {
+                        /* tm_wday as decimal (1-7) with Monday == 1 */
+                        /* 'O' for locale's alternative numeric symbols */
+                        s[rc++] = ( timeptr->tm_wday == 0 ) ? '7' : '0' + timeptr->tm_wday;
+                        break;
+                    }
+                case 'U':
+                    {
+                        /* week number of the year (first Sunday as the first day of week 1) as decimal (00-53) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        /* TODO: 'U' */
+                        break;
+                    }
+                case 'V':
+                    {
+                        /* week number as decimal (01-53) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        /* TODO: 'V' */
+                        break;
+                    }
+                case 'w':
+                    {
+                        /* tm_wday as decimal number (0-6) with Sunday == 0 */
+                        /* 'O' for locale's alternative numeric symbols */
+                        s[rc++] = '0' + timeptr->tm_wday;
+                        break;
+                    }
+                case 'W':
+                    {
+                        /* week number of the year (first Monday as the first day of week 1) as decimal (00-53) */
+                        /* 'O' for locale's alternative numeric symbols */
+                        /* TODO: 'W' */
+                        break;
+                    }
+                case 'x':
+                    {
+                        /* locale's date representation, %m/%d/%y for C locale */
+                        /* 'E' for locale's alternative representation */
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.date_format, timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'X':
+                    {
+                        /* locale's time representation, %T for C locale */
+                        /* 'E' for locale's alternative representation */
+                        size_t count = strftime( s + rc, maxsize - rc, _PDCLIB_lconv.time_format, timeptr );
+                        if ( count == 0 )
+                        {
+                            return 0;
+                        }
+                        else
+                        {
+                            rc += count;
+                        }
+                        break;
+                    }
+                case 'y':
+                    {
+                        /* last 2 digits of tm_year as decimal (00-99) */
+                        /* 'E' for offset from %EC (year only) in locale's alternative representation */
+                        /* 'O' for locale's alternative numeric symbols */
+                        if ( rc < ( maxsize - 2 ) )
+                        {
+                            div_t year = div( ( timeptr->tm_year % 100 ), 10 );
+                            s[rc++] = '0' + year.quot;
+                            s[rc++] = '0' + year.rem;
+                        }
+                        else
+                        {
+                            return 0;
+                        }
+                        break;
+                    }
+                case 'Y':
+                    {
+                        /* tm_year as decimal (e.g. 1997) */
+                        /* 'E' for locale's alternative representation */
+                        if ( rc < ( maxsize - 4 ) )
+                        {
+                            int year = timeptr->tm_year + 1900;
+
+                            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 'z':
+                    {
+                        /* tm_isdst / UTC offset in ISO8601 format (e.g. -0430 meaning 4 hours 30 minutes behind Greenwich), or no characters */
+                        /* TODO: 'z' */
+                        break;
+                    }
+                case 'Z':
+                    {
+                        /* tm_isdst / locale's time zone name or abbreviation, or no characters */
+                        /* TODO: 'Z' */
+                        break;
+                    }
+                case '%':
+                    {
+                        /* '%' character */
+                        s[rc++] = '%';
+                        break;
+                    }
+            }
+        }
+    }
+
     return 0;
 }
 
@@ -21,7 +521,72 @@ size_t strftime( char * restrict s, size_t maxsize, const char * restrict format
 
 int main( void )
 {
-    return NO_TESTDRIVER;
+#ifndef REGTEST
+    /* Replace with a call to mktime() once that is implemented. */
+    struct tm timeptr = { 59, 30, 12, 1, 9, 72, 0, 274, -1 };
+    char buffer[100];
+    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, "01 " ) == 0 );
+    TESTCASE( strftime( buffer, 100, "%j ", &timeptr ) == 4 );
+    TESTCASE( strcmp( buffer, "274 " ) == 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, "01:30:59 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 );
+#endif
+    return TEST_RESULTS;
 }
 
 #endif