/* * s t r f t i m e * * ANSI/POSIX compatible routine to converts a struct tm to * a text string under the guidance of a format string. * * Also supports the following extensions to the ANSI/POSIX * standards: * %e Day of month 1-31 * %R Time as %H:%M * %z Time difference to GMT ([+|-]%H%M) * * AMENDMENT HISTORY * ~~~~~~~~~~~~~~~~~ * 30 Aug 93 DJW - First version * Heavily based on the POSIX 1003.1-1988 compatible * time handling package by Ralf Wenk. * * 05 Mar 95 DJW - Added support for 'U' and 'W' options. * - On error condition, result is now always zero. * - Parameters now defined using _LIB_F4_ macro. * * 10 Nov 95 DJW - Added support for 'c', and 'x' options. * - Corrected 'x' option (it was really 'X' option) * - Changed to calling this routine recursively to * simplify some of the more complex combinations. */ #define _LIBRARY_SOURCE #include #include #include #define TRUE 1 #define FALSE 0 #define EOS '\0' #define SECS_PER_MINUTE ((time_t)60) #define SECS_PER_HOUR ((time_t)(60 * SECS_PER_MINUTE)) #define SECS_PER_DAY ((time_t)(24 * SECS_PER_HOUR)) #define SECS_PER_YEAR ((time_t)(365 * SECS_PER_DAY)) /* * Strftime places its output controled by the format string and by the * values in struct tm into the string starting at s. The maximum length of * the output string is specified by max, including the \0 character. It * returns the number of characters placed into s (excluding \0), or zero * if the output string would exceed maxsize. */ size_t strftime _LIB_F4_( char *, s, \ size_t, max, \ const char *, fmt, \ const struct tm *, tmp) { static char *lfmt[] = {"%c", "%02d/%02d/%02d", "%02d", "%d", "%.3s", "%2d", "%03d", "%02ld%02ld" }; char cbuff[26]; /* local expansion buffer */ char *m_ptr; /* points to am or pm */ int result; int yweek,start_of_week_day; time_t gmt_offset; /* used for %z */ tzset(); *s = EOS; m_ptr = tmp->tm_hour < 12 ? "AM" : "PM"; max--; /* remember \0 */ while ( *fmt != EOS && max != 0 ) { if ( *fmt != '%' ) { (void)sprintf( cbuff, lfmt[0], *fmt ); } else { switch ( *++fmt ) { case EOS: /* nothing left to do */ fmt--; cbuff[0] = EOS; break; case '%': /* % */ (void)strcpy( cbuff,"%"); break; case 'a': /* abbreviated weekday name */ (void)sprintf( cbuff, lfmt[4], __week_day[tmp->tm_wday] ); break; case 'A': /* full weekday name */ (void)strcpy( cbuff, __week_day[tmp->tm_wday] ); break; case 'b': /* abbreviated month name */ (void)sprintf( cbuff, lfmt[4], __month[tmp->tm_mon] ); break; case 'B': /* full month name */ (void)strcpy( cbuff, __month[tmp->tm_mon] ); break; case 'c': /* Local appropriate date/time */ (void) strftime (cbuff,sizeof(cbuff),"%a %b %d %X %Y",tmp); break; case 'd': /* day of month (01-31) */ (void)sprintf( cbuff, lfmt[2], tmp->tm_mday ); break; /* POSIX */ case 'D': /* date as %m/%d/%y */ (void)sprintf( cbuff, lfmt[1], tmp->tm_mon, tmp->tm_mday, tmp->tm_year ); break; /* EXTENSION */ case 'e': /* day of month ( 1-31) */ (void)sprintf( cbuff, lfmt[5], tmp->tm_mday ); break; /* POSIX */ case 'h': /* abbreviated month name */ (void)sprintf( cbuff, lfmt[4], __month[tmp->tm_mon] ); break; case 'H': /* hour (00-23) */ (void)sprintf( cbuff, lfmt[2], tmp->tm_hour ); break; case 'I': /* hour (00-12) */ (void)sprintf( cbuff, lfmt[2], tmp->tm_hour % 12 ); break; case 'j': /* day number of year (001-366) */ (void)sprintf( cbuff, lfmt[6], tmp->tm_yday + 1 ); break; case 'm': /* month number (01-12) */ (void)sprintf( cbuff, lfmt[2], tmp->tm_mon + 1 ); break; case 'M': /* minute (00-59) */ (void)sprintf( cbuff, lfmt[2], tmp->tm_min ); break; /* POSIX */ case 'n': /* Newline (\n) */ (void)strcpy( cbuff,"\n"); break; case 'p': /* ante meridian or post meridian */ (void)strcpy( cbuff, m_ptr ); break; /* POSIX */ case 'r': /* time as %H:%M:%S %p */ (void)strftime (cbuff,sizeof(cbuff),"%T %p",tmp); break; /* EXTENSION */ case 'R': /* time as %H:%M */ (void)strftime (cbuff,sizeof(cbuff),"%H:%M",tmp); break; case 'S': /* seconds (00-59) */ (void)sprintf( cbuff, lfmt[2], tmp->tm_sec ); break; /* POSIX */ case 't': /* Tab (\t) */ (void)strcpy( cbuff,"\t"); break; /* POSIX */ case 'T': /* time as %H:%M:%S */ (void)strftime (cbuff,sizeof(cbuff),"%R:%S",tmp); break; case 'U': /* year week (Sunday start) */ start_of_week_day = 0; yweek = ((tmp->tm_wday + 7 - start_of_week_day) % 7) - ((tmp->tm_yday) % 7) <= 0; yweek += tmp->tm_yday / 7; (void)sprintf( cbuff, lfmt[2], yweek); break; case 'w': /* weekday number (Sunday = 0) */ (void)sprintf( cbuff, lfmt[3], tmp->tm_wday ); break; case 'W': /* year week (Monday start) */ start_of_week_day = 1; yweek = ((tmp->tm_wday + 7 - start_of_week_day) % 7) - ((tmp->tm_yday) % 7) <= 0; yweek += tmp->tm_yday / 7; (void)sprintf( cbuff, lfmt[2], yweek); break; case 'x': /* date as wday Mon day, year */ (void)strftime(cbuff,sizeof(cbuff),"%a %b %d, %Y",tmp); break; case 'X': /* time as %H:%M:%S */ (void)strftime (cbuff,sizeof(cbuff),"%R:%S",tmp); break; case 'y': /* year within century (00-99) */ (void)sprintf( cbuff, lfmt[5], tmp->tm_year % 100 ); break; case 'Y': /* year as ccyy */ (void)sprintf( cbuff, lfmt[3], tmp->tm_year + 1900 ); break; /* EXTENSION */ case 'z': /* time ahead of GMT ([+|-]%H%M) */ gmt_offset = __lt_offset; if ( tmp->tm_isdst ) { gmt_offset += __dst_offset; } cbuff[0] = '+'; /* default is east of Greenwich */ if ( gmt_offset < 0 ) { /* no, we are west */ gmt_offset = - gmt_offset; cbuff[0] = '-'; } (void)sprintf( &cbuff[1], lfmt[7], gmt_offset / SECS_PER_HOUR, ( gmt_offset % SECS_PER_HOUR ) / SECS_PER_MINUTE ); break; case 'Z': /* time zone name */ (void)strcpy( cbuff, tzname[tmp->tm_isdst] ); break; default: (void)sprintf( cbuff, lfmt[0], *fmt ); break; } if ( max < strlen( cbuff )) { cbuff[max] = EOS; } } (void)strcat( s, cbuff ); max -= strlen( cbuff ); fmt++; } if (*fmt != EOS) { result = 0; } if ( result) { result = strlen( s ); } return( result ); }