busybox/coreutils/date.c

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/* vi: set sw=4 ts=4: */
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/*
* Mini date implementation for busybox
*
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* by Matthew Grant <grantma@anathoth.gen.nz>
*
* iso-format handling added by Robert Griebl <griebl@gmx.de>
* bugfixes and cleanup by Bernhard Reutner-Fischer
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*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
/* This 'date' command supports only 2 time setting formats,
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all the GNU strftime stuff (its in libc, lets use it),
setting time using UTC and displaying it, as well as
an RFC 2822 compliant date output for shell scripting
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mail commands */
/* Input parsing code is always bulky - used heavy duty libc stuff as
much as possible, missed out a lot of bounds checking */
/* Default input handling to save surprising some people */
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/* GNU coreutils 6.9 man page:
* date [OPTION]... [+FORMAT]
* date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
* -d, --date=STRING
* display time described by STRING, not `now'
* -f, --file=DATEFILE
* like --date once for each line of DATEFILE
* -r, --reference=FILE
* display the last modification time of FILE
* -R, --rfc-2822
* output date and time in RFC 2822 format.
* Example: Mon, 07 Aug 2006 12:34:56 -0600
* --rfc-3339=TIMESPEC
* output date and time in RFC 3339 format.
* TIMESPEC='date', 'seconds', or 'ns'
* Date and time components are separated by a single space:
* 2006-08-07 12:34:56-06:00
* -s, --set=STRING
* set time described by STRING
* -u, --utc, --universal
* print or set Coordinated Universal Time
*
* Busybox:
* long options are not supported
* -f is not supported
* -I seems to roughly match --rfc-3339, but -I has _optional_ param
* (thus "-I seconds" doesn't work, only "-Iseconds"),
* and does not support -Ins
* -D FMT is a bbox extension for _input_ conversion of -d DATE
*/
//kbuild:lib-$(CONFIG_DATE) += date.o
//config:config DATE
//config: bool "date"
//config: default y
//config: help
//config: date is used to set the system date or display the
//config: current time in the given format.
//config:
//config:config FEATURE_DATE_ISOFMT
//config: bool "Enable ISO date format output (-I)"
//config: default y
//config: depends on DATE
//config: help
//config: Enable option (-I) to output an ISO-8601 compliant
//config: date/time string.
//config:
//config:config FEATURE_DATE_NANO
//config: bool "Support %[num]N nanosecond format specifier"
//config: default n
//config: depends on DATE
//config: help
//config: Support %[num]N format specifier. Adds ~250 bytes of code.
//config:
//config:config FEATURE_DATE_COMPAT
//config: bool "Support weird 'date MMDDhhmm[[YY]YY][.ss]' format"
//config: default y
//config: depends on DATE
//config: help
//config: System time can be set by 'date -s DATE' and simply 'date DATE',
//config: but formats of DATE string are different. 'date DATE' accepts
//config: a rather weird MMDDhhmm[[YY]YY][.ss] format with completely
//config: unnatural placement of year between minutes and seconds.
//config: date -s (and other commands like touch -d) use more sensible
//config: formats (for one, ISO format YYYY-MM-DD hh:mm:ss.ssssss).
//config:
//config: With this option off, 'date DATE' is 'date -s DATE' support
//config: the same format. With it on, 'date DATE' additionally supports
//config: MMDDhhmm[[YY]YY][.ss] format.
#include "libbb.h"
#if ENABLE_FEATURE_DATE_NANO
# include <sys/syscall.h>
#endif
enum {
OPT_RFC2822 = (1 << 0), /* R */
OPT_SET = (1 << 1), /* s */
OPT_UTC = (1 << 2), /* u */
OPT_DATE = (1 << 3), /* d */
OPT_REFERENCE = (1 << 4), /* r */
OPT_TIMESPEC = (1 << 5) * ENABLE_FEATURE_DATE_ISOFMT, /* I */
OPT_HINT = (1 << 6) * ENABLE_FEATURE_DATE_ISOFMT, /* D */
};
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static void maybe_set_utc(int opt)
{
if (opt & OPT_UTC)
putenv((char*)"TZ=UTC0");
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}
#if ENABLE_LONG_OPTS
static const char date_longopts[] ALIGN1 =
"rfc-822\0" No_argument "R"
"rfc-2822\0" No_argument "R"
"set\0" Required_argument "s"
"utc\0" No_argument "u"
/* "universal\0" No_argument "u" */
"date\0" Required_argument "d"
"reference\0" Required_argument "r"
;
#endif
int date_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int date_main(int argc UNUSED_PARAM, char **argv)
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{
struct timespec ts;
struct tm tm_time;
char buf_fmt_dt2str[64];
unsigned opt;
int ifmt = -1;
char *date_str;
char *fmt_dt2str;
char *fmt_str2dt;
char *filename;
char *isofmt_arg = NULL;
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opt_complementary = "d--s:s--d"
IF_FEATURE_DATE_ISOFMT(":R--I:I--R");
IF_LONG_OPTS(applet_long_options = date_longopts;)
opt = getopt32(argv, "Rs:ud:r:"
IF_FEATURE_DATE_ISOFMT("I::D:"),
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&date_str, &date_str, &filename
IF_FEATURE_DATE_ISOFMT(, &isofmt_arg, &fmt_str2dt));
argv += optind;
maybe_set_utc(opt);
if (ENABLE_FEATURE_DATE_ISOFMT && (opt & OPT_TIMESPEC)) {
ifmt = 0; /* default is date */
if (isofmt_arg) {
static const char isoformats[] ALIGN1 =
"date\0""hours\0""minutes\0""seconds\0"; /* ns? */
ifmt = index_in_substrings(isoformats, isofmt_arg);
if (ifmt < 0)
bb_show_usage();
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}
}
fmt_dt2str = NULL;
if (argv[0] && argv[0][0] == '+') {
fmt_dt2str = &argv[0][1]; /* skip over the '+' */
argv++;
}
if (!(opt & (OPT_SET | OPT_DATE))) {
opt |= OPT_SET;
date_str = argv[0]; /* can be NULL */
if (date_str) {
#if ENABLE_FEATURE_DATE_COMPAT
int len = strspn(date_str, "0123456789");
if (date_str[len] == '\0'
|| (date_str[len] == '.'
&& isdigit(date_str[len+1])
&& isdigit(date_str[len+2])
&& date_str[len+3] == '\0'
)
) {
/* Dreaded MMDDhhmm[[CC]YY][.ss] format!
* It does not match -d or -s format.
* Some users actually do use it.
*/
len -= 8;
if (len < 0 || len > 4 || (len & 1))
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
if (len != 0) { /* move YY or CCYY to front */
char buf[4];
memcpy(buf, date_str + 8, len);
memmove(date_str + len, date_str, 8);
memcpy(date_str, buf, len);
}
}
#endif
argv++;
}
}
if (*argv)
bb_show_usage();
/* Now we have parsed all the information except the date format
* which depends on whether the clock is being set or read */
if (opt & OPT_REFERENCE) {
struct stat statbuf;
xstat(filename, &statbuf);
ts.tv_sec = statbuf.st_mtime;
#if ENABLE_FEATURE_DATE_NANO
ts.tv_nsec = statbuf.st_mtim.tv_nsec;
#endif
} else {
#if ENABLE_FEATURE_DATE_NANO
/* libc has incredibly messy way of doing this,
* typically requiring -lrt. We just skip all this mess */
syscall(__NR_clock_gettime, CLOCK_REALTIME, &ts);
#else
time(&ts.tv_sec);
#endif
}
localtime_r(&ts.tv_sec, &tm_time);
/* If date string is given, update tm_time, and maybe set date */
if (date_str != NULL) {
/* Zero out fields - take her back to midnight! */
tm_time.tm_sec = 0;
tm_time.tm_min = 0;
tm_time.tm_hour = 0;
/* Process any date input to UNIX time since 1 Jan 1970 */
if (ENABLE_FEATURE_DATE_ISOFMT && (opt & OPT_HINT)) {
if (strptime(date_str, fmt_str2dt, &tm_time) == NULL)
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
} else {
parse_datestr(date_str, &tm_time);
}
/* Correct any day of week and day of year etc. fields */
tm_time.tm_isdst = -1; /* Be sure to recheck dst */
ts.tv_sec = validate_tm_time(date_str, &tm_time);
maybe_set_utc(opt);
/* if setting time, set it */
if ((opt & OPT_SET) && stime(&ts.tv_sec) < 0) {
bb_perror_msg("can't set date");
}
}
/* Display output */
/* Deal with format string */
if (fmt_dt2str == NULL) {
int i;
fmt_dt2str = buf_fmt_dt2str;
if (ENABLE_FEATURE_DATE_ISOFMT && ifmt >= 0) {
/* -I[SPEC]: 0:date 1:hours 2:minutes 3:seconds */
strcpy(fmt_dt2str, "%Y-%m-%dT%H:%M:%S");
i = 8 + 3 * ifmt;
if (ifmt != 0) {
/* TODO: if (ifmt==4) i += sprintf(&fmt_dt2str[i], ",%09u", nanoseconds); */
format_utc:
fmt_dt2str[i++] = '%';
fmt_dt2str[i++] = (opt & OPT_UTC) ? 'Z' : 'z';
}
fmt_dt2str[i] = '\0';
} else if (opt & OPT_RFC2822) {
/* -R. undo busybox.c setlocale */
if (ENABLE_LOCALE_SUPPORT)
setlocale(LC_TIME, "C");
strcpy(fmt_dt2str, "%a, %d %b %Y %H:%M:%S ");
i = sizeof("%a, %d %b %Y %H:%M:%S ")-1;
goto format_utc;
} else { /* default case */
fmt_dt2str = (char*)"%a %b %e %H:%M:%S %Z %Y";
}
}
#if ENABLE_FEATURE_DATE_NANO
else {
/* User-specified fmt_dt2str */
/* Search for and process "%N" */
char *p = fmt_dt2str;
while ((p = strchr(p, '%')) != NULL) {
int n, m;
unsigned pres, scale;
p++;
if (*p == '%') {
p++;
continue;
}
n = strspn(p, "0123456789");
if (p[n] != 'N') {
p += n;
continue;
}
/* We have "%[nnn]N" */
p[-1] = '\0';
p[n] = '\0';
scale = 1;
pres = 9;
if (n) {
pres = xatoi_u(p);
if (pres == 0)
pres = 9;
m = 9 - pres;
while (--m >= 0)
scale *= 10;
}
m = p - fmt_dt2str;
p += n + 1;
fmt_dt2str = xasprintf("%s%0*u%s", fmt_dt2str, pres, (unsigned)ts.tv_nsec / scale, p);
p = fmt_dt2str + m;
}
}
#endif
#define date_buf bb_common_bufsiz1
if (*fmt_dt2str == '\0') {
/* With no format string, just print a blank line */
date_buf[0] = '\0';
} else {
/* Handle special conversions */
if (strncmp(fmt_dt2str, "%f", 2) == 0) {
fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
}
/* Generate output string */
strftime(date_buf, sizeof(date_buf), fmt_dt2str, &tm_time);
}
puts(date_buf);
return EXIT_SUCCESS;
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}