asctime.c revision 225736
1170525Syongari/* 2170525Syongari** This file is in the public domain, so clarified as of 3170525Syongari** 1996-06-05 by Arthur David Olson. 4170525Syongari*/ 5170525Syongari 6170525Syongari/* 7170525Syongari** Avoid the temptation to punt entirely to strftime; 8170525Syongari** the output of strftime is supposed to be locale specific 9170525Syongari** whereas the output of asctime is supposed to be constant. 10170525Syongari*/ 11170525Syongari 12170525Syongari#include <sys/cdefs.h> 13170525Syongari#ifndef lint 14170525Syongari#ifndef NOID 15170525Syongaristatic char elsieid[] __unused = "@(#)asctime.c 8.5"; 16170525Syongari#endif /* !defined NOID */ 17170525Syongari#endif /* !defined lint */ 18170525Syongari__FBSDID("$FreeBSD: stable/9/contrib/tzcode/stdtime/asctime.c 214411 2010-10-27 07:14:46Z edwin $"); 19170525Syongari 20170525Syongari/*LINTLIBRARY*/ 21170525Syongari 22170525Syongari#include "namespace.h" 23170525Syongari#include "private.h" 24170525Syongari#include "un-namespace.h" 25170525Syongari#include "tzfile.h" 26170525Syongari 27170525Syongari/* 28170525Syongari** Some systems only handle "%.2d"; others only handle "%02d"; 29170525Syongari** "%02.2d" makes (most) everybody happy. 30170525Syongari** At least some versions of gcc warn about the %02.2d; 31170525Syongari** we conditionalize below to avoid the warning. 32170525Syongari*/ 33170525Syongari/* 34170525Syongari** All years associated with 32-bit time_t values are exactly four digits long; 35170525Syongari** some years associated with 64-bit time_t values are not. 36170525Syongari** Vintage programs are coded for years that are always four digits long 37170525Syongari** and may assume that the newline always lands in the same place. 38170525Syongari** For years that are less than four digits, we pad the output with 39170525Syongari** leading zeroes to get the newline in the traditional place. 40170525Syongari** The -4 ensures that we get four characters of output even if 41170525Syongari** we call a strftime variant that produces fewer characters for some years. 42170525Syongari** The ISO C 1999 and POSIX 1003.1-2004 standards prohibit padding the year, 43170525Syongari** but many implementations pad anyway; most likely the standards are buggy. 44170525Syongari*/ 45170525Syongari#ifdef __GNUC__ 46170525Syongari#define ASCTIME_FMT "%.3s %.3s%3d %2.2d:%2.2d:%2.2d %-4s\n" 47170525Syongari#else /* !defined __GNUC__ */ 48170525Syongari#define ASCTIME_FMT "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %-4s\n" 49170525Syongari#endif /* !defined __GNUC__ */ 50170525Syongari/* 51170525Syongari** For years that are more than four digits we put extra spaces before the year 52170525Syongari** so that code trying to overwrite the newline won't end up overwriting 53170525Syongari** a digit within a year and truncating the year (operating on the assumption 54170525Syongari** that no output is better than wrong output). 55170525Syongari*/ 56170525Syongari#ifdef __GNUC__ 57170525Syongari#define ASCTIME_FMT_B "%.3s %.3s%3d %2.2d:%2.2d:%2.2d %s\n" 58170525Syongari#else /* !defined __GNUC__ */ 59170525Syongari#define ASCTIME_FMT_B "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %s\n" 60170525Syongari#endif /* !defined __GNUC__ */ 61170525Syongari 62170525Syongari#define STD_ASCTIME_BUF_SIZE 26 63170525Syongari/* 64170525Syongari** Big enough for something such as 65170525Syongari** ??? ???-2147483648 -2147483648:-2147483648:-2147483648 -2147483648\n 66170525Syongari** (two three-character abbreviations, five strings denoting integers, 67170525Syongari** seven explicit spaces, two explicit colons, a newline, 68170525Syongari** and a trailing ASCII nul). 69170525Syongari** The values above are for systems where an int is 32 bits and are provided 70170525Syongari** as an example; the define below calculates the maximum for the system at 71170525Syongari** hand. 72170525Syongari*/ 73170525Syongari#define MAX_ASCTIME_BUF_SIZE (2*3+5*INT_STRLEN_MAXIMUM(int)+7+2+1+1) 74170525Syongari 75170525Syongaristatic char buf_asctime[MAX_ASCTIME_BUF_SIZE]; 76170525Syongari 77170525Syongari/* 78170525Syongari** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition. 79170525Syongari*/ 80170525Syongari 81170525Syongarichar * 82170525Syongariasctime_r(timeptr, buf) 83170525Syongariconst struct tm * timeptr; 84170525Syongarichar * buf; 85170525Syongari{ 86170525Syongari static const char wday_name[][3] = { 87170525Syongari "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" 88170525Syongari }; 89170525Syongari static const char mon_name[][3] = { 90170525Syongari "Jan", "Feb", "Mar", "Apr", "May", "Jun", 91170525Syongari "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 92227908Smarius }; 93170525Syongari const char * wn; 94170525Syongari const char * mn; 95170525Syongari char year[INT_STRLEN_MAXIMUM(int) + 2]; 96170525Syongari char result[MAX_ASCTIME_BUF_SIZE]; 97170525Syongari 98170525Syongari if (timeptr == NULL) { 99170525Syongari errno = EINVAL; 100221407Smarius return strcpy(buf, "??? ??? ?? ??:??:?? ????\n"); 101170525Syongari } 102170525Syongari if (timeptr->tm_wday < 0 || timeptr->tm_wday >= DAYSPERWEEK) 103170525Syongari wn = "???"; 104170525Syongari else wn = wday_name[timeptr->tm_wday]; 105170525Syongari if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR) 106170525Syongari mn = "???"; 107170525Syongari else mn = mon_name[timeptr->tm_mon]; 108170525Syongari /* 109170525Syongari ** Use strftime's %Y to generate the year, to avoid overflow problems 110221407Smarius ** when computing timeptr->tm_year + TM_YEAR_BASE. 111221407Smarius ** Assume that strftime is unaffected by other out-of-range members 112221407Smarius ** (e.g., timeptr->tm_mday) when processing "%Y". 113221407Smarius */ 114170525Syongari (void) strftime(year, sizeof year, "%Y", timeptr); 115170525Syongari /* 116170525Syongari ** We avoid using snprintf since it's not available on all systems. 117221407Smarius */ 118221407Smarius (void) sprintf(result, 119221407Smarius ((strlen(year) <= 4) ? ASCTIME_FMT : ASCTIME_FMT_B), 120221407Smarius wn, mn, 121221407Smarius timeptr->tm_mday, timeptr->tm_hour, 122221407Smarius timeptr->tm_min, timeptr->tm_sec, 123170525Syongari year); 124170525Syongari if (strlen(result) < STD_ASCTIME_BUF_SIZE || buf == buf_asctime) 125170525Syongari return strcpy(buf, result); 126170525Syongari else { 127170525Syongari#ifdef EOVERFLOW 128170525Syongari errno = EOVERFLOW; 129170525Syongari#else /* !defined EOVERFLOW */ 130170525Syongari errno = EINVAL; 131170525Syongari#endif /* !defined EOVERFLOW */ 132170525Syongari return NULL; 133170525Syongari } 134221407Smarius} 135221407Smarius 136170525Syongari/* 137170525Syongari** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition. 138170525Syongari*/ 139170525Syongari 140170525Syongarichar * 141170525Syongariasctime(timeptr) 142170525Syongariconst struct tm * timeptr; 143170525Syongari{ 144170525Syongari return asctime_r(timeptr, buf_asctime); 145170525Syongari} 146170525Syongari