busybox/libbb/time.c
Ron Yorston 3512ef8018 libbb: code shrink parse_datestr
The default build uses strptime() in parse_datestr() to support the
'month_name d HH:MM:SS YYYY' format of GNU date.  If we've linked
with strptime() there's an advantage is using it for other formats
too.

There's no change to the non-default, non-DESKTOP build.

function                                             old     new   delta
fmt_str                                                -     106    +106
.rodata                                            99216   99145     -71
parse_datestr                                        948     624    -324
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 106/-395)         Total: -289 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-09-15 08:09:45 +02:00

340 lines
8.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 2007 Denys Vlasenko
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
#include "libbb.h"
void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
{
char end = '\0';
#if ENABLE_DESKTOP
/*
* strptime is BIG: ~1k in uclibc, ~10k in glibc
* We need it for 'month_name d HH:MM:SS YYYY', supported by GNU date,
* but if we've linked it we might as well use it for everything.
*/
static const char fmt_str[] ALIGN1 =
"%R" "\0" /* HH:MM */
"%T" "\0" /* HH:MM:SS */
"%m.%d-%R" "\0" /* mm.dd-HH:MM */
"%m.%d-%T" "\0" /* mm.dd-HH:MM:SS */
"%Y.%m.%d-%R" "\0" /* yyyy.mm.dd-HH:MM */
"%Y.%m.%d-%T" "\0" /* yyyy.mm.dd-HH:MM:SS */
"%b %d %T %Y" "\0" /* month_name d HH:MM:SS YYYY */
"%Y-%m-%d %R" "\0" /* yyyy-mm-dd HH:MM */
"%Y-%m-%d %T" "\0" /* yyyy-mm-dd HH:MM:SS */
"%Y-%m-%d %H" "\0" /* yyyy-mm-dd HH */
"%Y-%m-%d" "\0" /* yyyy-mm-dd */
/* extra NUL */;
struct tm save;
const char *fmt;
char *endp;
save = *ptm;
fmt = fmt_str;
while (*fmt) {
endp = strptime(date_str, fmt, ptm);
if (endp && *endp == '\0')
return;
*ptm = save;
while (*++fmt)
continue;
++fmt;
}
#else
const char *last_colon = strrchr(date_str, ':');
if (last_colon != NULL) {
/* Parse input and assign appropriately to ptm */
/* HH:MM */
if (sscanf(date_str, "%u:%u%c",
&ptm->tm_hour,
&ptm->tm_min,
&end) >= 2
) {
/* no adjustments needed */
} else
/* mm.dd-HH:MM */
if (sscanf(date_str, "%u.%u-%u:%u%c",
&ptm->tm_mon, &ptm->tm_mday,
&ptm->tm_hour, &ptm->tm_min,
&end) >= 4
) {
/* Adjust month from 1-12 to 0-11 */
ptm->tm_mon -= 1;
} else
/* yyyy.mm.dd-HH:MM */
if (sscanf(date_str, "%u.%u.%u-%u:%u%c", &ptm->tm_year,
&ptm->tm_mon, &ptm->tm_mday,
&ptm->tm_hour, &ptm->tm_min,
&end) >= 5
/* yyyy-mm-dd HH:MM */
|| sscanf(date_str, "%u-%u-%u %u:%u%c", &ptm->tm_year,
&ptm->tm_mon, &ptm->tm_mday,
&ptm->tm_hour, &ptm->tm_min,
&end) >= 5
) {
ptm->tm_year -= 1900; /* Adjust years */
ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
} else
{
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
}
if (end == ':') {
/* xxx:SS */
if (sscanf(last_colon + 1, "%u%c", &ptm->tm_sec, &end) == 1)
end = '\0';
/* else end != NUL and we error out */
}
} else
if (strchr(date_str, '-')
/* Why strchr('-') check?
* sscanf below will trash ptm->tm_year, this breaks
* if parse_str is "10101010" (iow, "MMddhhmm" form)
* because we destroy year. Do these sscanf
* only if we saw a dash in parse_str.
*/
/* yyyy-mm-dd HH */
&& (sscanf(date_str, "%u-%u-%u %u%c", &ptm->tm_year,
&ptm->tm_mon, &ptm->tm_mday,
&ptm->tm_hour,
&end) >= 4
/* yyyy-mm-dd */
|| sscanf(date_str, "%u-%u-%u%c", &ptm->tm_year,
&ptm->tm_mon, &ptm->tm_mday,
&end) >= 3
)
) {
ptm->tm_year -= 1900; /* Adjust years */
ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
} else
#endif /* ENABLE_DESKTOP */
if (date_str[0] == '@') {
time_t t;
if (sizeof(t) <= sizeof(long))
t = bb_strtol(date_str + 1, NULL, 10);
else /* time_t is 64 bits but longs are smaller */
t = bb_strtoll(date_str + 1, NULL, 10);
if (!errno) {
struct tm *lt = localtime(&t);
if (lt) {
*ptm = *lt;
return;
}
}
end = '1';
} else {
/* Googled the following on an old date manpage:
*
* The canonical representation for setting the date/time is:
* cc Century (either 19 or 20)
* yy Year in abbreviated form (e.g. 89, 06)
* mm Numeric month, a number from 1 to 12
* dd Day, a number from 1 to 31
* HH Hour, a number from 0 to 23
* MM Minutes, a number from 0 to 59
* .SS Seconds, a number from 0 to 61 (with leap seconds)
* Everything but the minutes is optional
*
* "touch -t DATETIME" format: [[[[[YY]YY]MM]DD]hh]mm[.ss]
* Some, but not all, Unix "date DATETIME" commands
* move [[YY]YY] past minutes mm field (!).
* Coreutils date does it, and SUS mandates it.
* (date -s DATETIME does not support this format. lovely!)
* In bbox, this format is special-cased in date applet
* (IOW: this function assumes "touch -t" format).
*/
unsigned cur_year = ptm->tm_year;
int len = strchrnul(date_str, '.') - date_str;
/* MM[.SS] */
if (len == 2 && sscanf(date_str, "%2u%2u%2u%2u""%2u%c" + 12,
&ptm->tm_min,
&end) >= 1) {
} else
/* HHMM[.SS] */
if (len == 4 && sscanf(date_str, "%2u%2u%2u""%2u%2u%c" + 9,
&ptm->tm_hour,
&ptm->tm_min,
&end) >= 2) {
} else
/* ddHHMM[.SS] */
if (len == 6 && sscanf(date_str, "%2u%2u""%2u%2u%2u%c" + 6,
&ptm->tm_mday,
&ptm->tm_hour,
&ptm->tm_min,
&end) >= 3) {
} else
/* mmddHHMM[.SS] */
if (len == 8 && sscanf(date_str, "%2u""%2u%2u%2u%2u%c" + 3,
&ptm->tm_mon,
&ptm->tm_mday,
&ptm->tm_hour,
&ptm->tm_min,
&end) >= 4) {
/* Adjust month from 1-12 to 0-11 */
ptm->tm_mon -= 1;
} else
/* yymmddHHMM[.SS] */
if (len == 10 && sscanf(date_str, "%2u%2u%2u%2u%2u%c",
&ptm->tm_year,
&ptm->tm_mon,
&ptm->tm_mday,
&ptm->tm_hour,
&ptm->tm_min,
&end) >= 5) {
/* Adjust month from 1-12 to 0-11 */
ptm->tm_mon -= 1;
if ((int)cur_year >= 50) { /* >= 1950 */
/* Adjust year: */
/* 1. Put it in the current century */
ptm->tm_year += (cur_year / 100) * 100;
/* 2. If too far in the past, +100 years */
if (ptm->tm_year < cur_year - 50)
ptm->tm_year += 100;
/* 3. If too far in the future, -100 years */
if (ptm->tm_year > cur_year + 50)
ptm->tm_year -= 100;
}
} else
/* ccyymmddHHMM[.SS] */
if (len == 12 && sscanf(date_str, "%4u%2u%2u%2u%2u%c",
&ptm->tm_year,
&ptm->tm_mon,
&ptm->tm_mday,
&ptm->tm_hour,
&ptm->tm_min,
&end) >= 5) {
ptm->tm_year -= 1900; /* Adjust years */
ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
} else {
err:
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
}
ptm->tm_sec = 0; /* assume zero if [.SS] is not given */
if (end == '.') {
/* xxx.SS */
if (sscanf(strchr(date_str, '.') + 1, "%u%c",
&ptm->tm_sec, &end) == 1)
end = '\0';
/* else end != NUL and we error out */
}
/* Users were confused by "date -s 20180923"
* working (not in the way they were expecting).
* It was interpreted as MMDDhhmm, and not bothered by
* "month #20" in the least. Prevent such cases:
*/
if (ptm->tm_sec > 60 /* allow "23:60" leap second */
|| ptm->tm_min > 59
|| ptm->tm_hour > 23
|| ptm->tm_mday > 31
|| ptm->tm_mon > 11 /* month# is 0..11, not 1..12 */
) {
goto err;
}
}
if (end != '\0') {
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
}
}
time_t FAST_FUNC validate_tm_time(const char *date_str, struct tm *ptm)
{
time_t t = mktime(ptm);
if (t == (time_t) -1L) {
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
}
return t;
}
static char* strftime_fmt(char *buf, unsigned len, time_t *tp, const char *fmt)
{
time_t t;
if (!tp) {
tp = &t;
time(tp);
}
/* Returns pointer to NUL */
return buf + strftime(buf, len, fmt, localtime(tp));
}
char* FAST_FUNC strftime_HHMMSS(char *buf, unsigned len, time_t *tp)
{
return strftime_fmt(buf, len, tp, "%H:%M:%S");
}
char* FAST_FUNC strftime_YYYYMMDDHHMMSS(char *buf, unsigned len, time_t *tp)
{
return strftime_fmt(buf, len, tp, "%Y-%m-%d %H:%M:%S");
}
#if ENABLE_MONOTONIC_SYSCALL
/* Old glibc (< 2.3.4) does not provide this constant. We use syscall
* directly so this definition is safe. */
#ifndef CLOCK_MONOTONIC
#define CLOCK_MONOTONIC 1
#endif
static void get_mono(struct timespec *ts)
{
if (clock_gettime(CLOCK_MONOTONIC, ts))
bb_simple_error_msg_and_die("clock_gettime(MONOTONIC) failed");
}
unsigned long long FAST_FUNC monotonic_ns(void)
{
struct timespec ts;
get_mono(&ts);
return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
}
unsigned long long FAST_FUNC monotonic_us(void)
{
struct timespec ts;
get_mono(&ts);
return ts.tv_sec * 1000000ULL + ts.tv_nsec/1000;
}
unsigned long long FAST_FUNC monotonic_ms(void)
{
struct timespec ts;
get_mono(&ts);
return ts.tv_sec * 1000ULL + ts.tv_nsec/1000000;
}
unsigned FAST_FUNC monotonic_sec(void)
{
struct timespec ts;
get_mono(&ts);
return ts.tv_sec;
}
#else
unsigned long long FAST_FUNC monotonic_ns(void)
{
struct timeval tv;
xgettimeofday(&tv);
return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000;
}
unsigned long long FAST_FUNC monotonic_us(void)
{
struct timeval tv;
xgettimeofday(&tv);
return tv.tv_sec * 1000000ULL + tv.tv_usec;
}
unsigned long long FAST_FUNC monotonic_ms(void)
{
struct timeval tv;
xgettimeofday(&tv);
return tv.tv_sec * 1000ULL + tv.tv_usec / 1000;
}
unsigned FAST_FUNC monotonic_sec(void)
{
return time(NULL);
}
#endif