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git.saurik.com Git - apple/libc.git/blob - stdtime/FreeBSD/asctime.c
2 ** This file is in the public domain, so clarified as of
3 ** 1996-06-05 by Arthur David Olson.
7 ** Avoid the temptation to punt entirely to strftime;
8 ** the output of strftime is supposed to be locale specific
9 ** whereas the output of asctime is supposed to be constant.
12 #include <sys/cdefs.h>
16 static char elsieid
[] __unused
= "@(#)asctime.c 8.2";
17 #endif /* !defined NOID */
18 #endif /* !defined lint */
19 __FBSDID("$FreeBSD: src/lib/libc/stdtime/asctime.c,v 1.13 2009/05/23 06:31:50 edwin Exp $");
23 #include "namespace.h"
25 #include "un-namespace.h"
29 ** Some systems only handle "%.2d"; others only handle "%02d";
30 ** "%02.2d" makes (most) everybody happy.
31 ** At least some versions of gcc warn about the %02.2d;
32 ** we conditionalize below to avoid the warning.
35 ** All years associated with 32-bit time_t values are exactly four digits long;
36 ** some years associated with 64-bit time_t values are not.
37 ** Vintage programs are coded for years that are always four digits long
38 ** and may assume that the newline always lands in the same place.
39 ** For years that are less than four digits, we pad the output with
40 ** leading zeroes to get the newline in the traditional place.
41 ** The -4 ensures that we get four characters of output even if
42 ** we call a strftime variant that produces fewer characters for some years.
43 ** The ISO C 1999 and POSIX 1003.1-2004 standards prohibit padding the year,
44 ** but many implementations pad anyway; most likely the standards are buggy.
47 #define ASCTIME_FMT "%.3s %.3s%3d %2.2d:%2.2d:%2.2d %-4s\n"
48 #else /* !defined __GNUC__ */
49 #define ASCTIME_FMT "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %-4s\n"
50 #endif /* !defined __GNUC__ */
52 ** For years that are more than four digits we put extra spaces before the year
53 ** so that code trying to overwrite the newline won't end up overwriting
54 ** a digit within a year and truncating the year (operating on the assumption
55 ** that no output is better than wrong output).
58 #define ASCTIME_FMT_B "%.3s %.3s%3d %2.2d:%2.2d:%2.2d %s\n"
59 #else /* !defined __GNUC__ */
60 #define ASCTIME_FMT_B "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %s\n"
61 #endif /* !defined __GNUC__ */
63 #define STD_ASCTIME_BUF_SIZE 26
65 ** Big enough for something such as
66 ** ??? ???-2147483648 -2147483648:-2147483648:-2147483648 -2147483648\n
67 ** (two three-character abbreviations, five strings denoting integers,
68 ** seven explicit spaces, two explicit colons, a newline,
69 ** and a trailing ASCII nul).
70 ** The values above are for systems where an int is 32 bits and are provided
71 ** as an example; the define below calculates the maximum for the system at
74 #define MAX_ASCTIME_BUF_SIZE (2*3+5*INT_STRLEN_MAXIMUM(int)+7+2+1+1)
76 static char buf_asctime
[MAX_ASCTIME_BUF_SIZE
];
79 ** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition.
83 asctime_r(const struct tm
* __restrict timeptr
, char * __restrict buf
)
85 static const char wday_name
[][3] = {
86 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
88 static const char mon_name
[][3] = {
89 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
90 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
94 char year
[INT_STRLEN_MAXIMUM(int) + 2];
95 char result
[MAX_ASCTIME_BUF_SIZE
];
97 if (timeptr
->tm_wday
< 0 || timeptr
->tm_wday
>= DAYSPERWEEK
)
99 else wn
= wday_name
[timeptr
->tm_wday
];
100 if (timeptr
->tm_mon
< 0 || timeptr
->tm_mon
>= MONSPERYEAR
)
102 else mn
= mon_name
[timeptr
->tm_mon
];
104 ** Use strftime's %Y to generate the year, to avoid overflow problems
105 ** when computing timeptr->tm_year + TM_YEAR_BASE.
106 ** Assume that strftime is unaffected by other out-of-range members
107 ** (e.g., timeptr->tm_mday) when processing "%Y".
109 (void) strftime_l(year
, sizeof(year
), "%Y", timeptr
, NULL
);
111 ** We avoid using snprintf since it's not available on all systems.
113 (void) sprintf(result
,
114 ((strlen(year
) <= 4) ? ASCTIME_FMT
: ASCTIME_FMT_B
),
116 timeptr
->tm_mday
, timeptr
->tm_hour
,
117 timeptr
->tm_min
, timeptr
->tm_sec
,
119 if (strlen(result
) < STD_ASCTIME_BUF_SIZE
|| buf
== buf_asctime
) {
120 (void) strcpy(buf
, result
);
125 #else /* !defined EOVERFLOW */
127 #endif /* !defined EOVERFLOW */
133 ** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition.
138 const struct tm
* timeptr
;
140 return asctime_r(timeptr
, buf_asctime
);