cosmopolitan/libc/time/iso8601.c
Justine Tunney f7ff77d865
Make fixes and improvements
- Invent iso8601us() for faster timestamps
- Improve --strace descriptions of sigset_t
- Rebuild the Landlock Make bootstrap binary
- Introduce MODE=sysv for non-Windows builds
- Permit OFD fcntl() locks under pledge(flock)
- redbean can now protect your kernel from ddos
- Have vfork() fallback to sys_fork() not fork()
- Change kmalloc() to not die when out of memory
- Improve documentation for some termios functions
- Rewrite putenv() and friends to conform to POSIX
- Fix linenoise + strace verbosity issue on Windows
- Fix regressions in our ability to show backtraces
- Change redbean SetHeader() to no-op if value is nil
- Improve fcntl() so SQLite locks work in non-WAL mode
- Remove some unnecessary work during fork() on Windows
- Create redbean-based SSL reverse proxy for IPv4 TurfWar
- Fix ape/apeinstall.sh warning when using non-bash shells
- Add ProgramTrustedIp(), and IsTrustedIp() APIs to redbean
- Support $PWD, $UID, $GID, and $EUID in command interpreter
- Introduce experimental JTqFpD APE prefix for non-Windows builds
- Invent blackhole daemon for firewalling IP addresses via UNIX named socket
- Add ProgramTokenBucket(), AcquireToken(), and CountTokens() APIs to redbean
2022-10-19 07:19:19 -07:00

95 lines
3.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/time/struct/tm.h"
#include "libc/time/time.h"
/**
* Converts timestamp to ISO-8601 formatted string.
*
* For example:
*
* char *GetZuluTime(void) {
* char *p;
* struct tm tm;
* struct timespec ts;
* static _Thread_local int64_t last;
* static _Thread_local char str[21];
* clock_gettime(0, &ts);
* if (ts.tv_sec != last) {
* gmtime_r(&ts.tv_sec, &tm);
* last = ts.tv_sec;
* stpcpy(iso8601(str, &tm), "Z");
* }
* return str;
* }
*
* Will return timestamps that look like:
*
* 2020-01-01T13:14:15Z
*
* The generated timestamp is always exactly 19 characters long. It is
* also always nul terminated too.
*
* This function defines no failure conditions. The results of passing
* timestamp values outside of the appropriate intervals is undefined.
*
* @param p is buffer with at least 20 bytes
* @param tm has valid gmtime_r() or localtime_r() output
* @return pointer to nul terminator within `p`, cf. stpcpy()
* @see iso8601us() for microsecond timestamps
* @asyncsignalsafe
* @threadsafe
*/
char *iso8601(char p[hasatleast 20], struct tm *tm) {
int x;
x = tm->tm_year + 1900;
_unassert(0 <= x && x <= 9999);
*p++ = '0' + x / 1000;
*p++ = '0' + x / 100 % 10;
*p++ = '0' + x / 10 % 10;
*p++ = '0' + x % 10;
*p++ = '-';
x = tm->tm_mon + 1;
_unassert(1 <= x && x <= 12);
*p++ = '0' + x / 10;
*p++ = '0' + x % 10;
*p++ = '-';
x = tm->tm_mday;
_unassert(1 <= x && x <= 31);
*p++ = '0' + x / 10;
*p++ = '0' + x % 10;
*p++ = 'T';
x = tm->tm_hour;
_unassert(0 <= x && x <= 23);
*p++ = '0' + x / 10;
*p++ = '0' + x % 10;
*p++ = ':';
x = tm->tm_min;
_unassert(0 <= x && x <= 59);
*p++ = '0' + x / 10;
*p++ = '0' + x % 10;
*p++ = ':';
x = tm->tm_sec;
_unassert(0 <= x && x <= 60);
*p++ = '0' + x / 10;
*p++ = '0' + x % 10;
*p = 0;
return p;
}