/* strftime( char * restrict, size_t, const char * restrict, const struct tm * restrict ) This file is part of the Public Domain C Library (PDCLib). Permission is granted to use, modify, and / or redistribute at will. */ #include #include #include #include #ifndef REGTEST /* 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; } #endif #ifdef TEST #include "_PDCLIB_test.h" int main( void ) { #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