diff options
Diffstat (limited to 'src/time/strftime.c')
| -rw-r--r-- | src/time/strftime.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/time/strftime.c b/src/time/strftime.c new file mode 100644 index 00000000..abf56bc5 --- /dev/null +++ b/src/time/strftime.c @@ -0,0 +1,187 @@ +#include <time.h> +#include "stdio.h" +#include "nonstd/assert.h" +#include "nonstd/internal.h" +#include "locale.h" +#include "nonstd/locale.h" + +/** convert time to a formatted string **/ + +size_t strftime(char * restrict s, size_t maxsize, const char * restrict format, const struct tm * restrict timeptr) +{ + size_t converted = 0, i, j; + char buf[64]; + struct __locale_t *lc; + + ASSERT_NONNULL(s); + ASSERT_NONNULL(format); + ASSERT_NONNULL(timeptr); + + lc = __libc(THREAD_LOCALE); + + for (i = 0; format[i] != '\0' && converted < maxsize; i++) { + if (format[i] != '%') { + s[converted++] = format[i]; + continue; + } + + switch (format[++i]) { + case 'a': + sprintf(buf, "%s", lc->lc_time.abday[timeptr->tm_wday]); + break; + + case 'A': + sprintf(buf, "%s", lc->lc_time.day[timeptr->tm_wday]); + break; + + case 'b': + sprintf(buf, "%s", lc->lc_time.abmon[timeptr->tm_mon]); + break; + + case 'B': + sprintf(buf, "%s", lc->lc_time.mon[timeptr->tm_mon]); + break; + + case 'c': + /* FIXME: expand this */ + sprintf(buf, "%s", lc->lc_time.d_t_fmt); + break; + + case 'd': + sprintf(buf, "%02d", timeptr->tm_mday); + break; + + case 'H': + sprintf(buf, "%02d", timeptr->tm_hour); + break; + + case 'I': + sprintf(buf, "%02d", (timeptr->tm_hour + 1) % 13); + break; + + case 'j': + sprintf(buf, "%03d", timeptr->tm_yday + 1); + break; + + case 'm': + sprintf(buf, "%02d", timeptr->tm_mon + 1); + break; + + case 'M': + sprintf(buf, "%02d", timeptr->tm_min); + break; + + case 'p': + sprintf(buf, "%s", lc->lc_time.am_pm[timeptr->tm_hour < 12 ? 0 : 1]); + break; + + case 'S': + sprintf(buf, "%02d", timeptr->tm_sec); + break; + + case 'U': + /* TODO: two digit week of year, sunday based week */ + sprintf(buf, "%02d", timeptr->tm_yday / 7); + break; + + case 'w': + sprintf(buf, "%1d", timeptr->tm_wday); + break; + + case 'W': + /* TODO: two digit week of year, monday based week */ + sprintf(buf, "%02d", timeptr->tm_yday / 7); + break; + + case 'x': + /* TODO: expand this */ + sprintf(buf, "%s", lc->lc_time.d_fmt); + break; + + case 'X': + /* TODO: expand this */ + sprintf(buf, "%s", lc->lc_time.t_fmt); + break; + + case 'y': + sprintf(buf, "%02d", timeptr->tm_year % 100); + break; + + case 'Y': + sprintf(buf, "%d", timeptr->tm_year + 1900); + break; + + case 'Z': + sprintf(buf, "%s", "timezone"); + break; + + case '%': + sprintf(buf, "%%"); + break; + + default: + sprintf(buf, "UNDEFINED"); + /* undefined behavior */ + break; + } + + for (j = 0; buf[j] != '\0'; j++) { + s[converted++] = buf[j]; + if (converted >= maxsize - 1) { + break; + } + } + } + + s[converted++] = '\0'; + + if (converted >= maxsize) { + return 0; + } + + return converted; +} + +/*** +converts the time at ARGUMENT(timeptr) to a string of no more than +ARGUMENT(maxsize) bytes at ARGUMENT(s). The format of the converted string +is specified by ARGUMENT(format). The string at ARGUMENT(format) may contain +conversion specifiers, which consist of a CHAR(%) followed by one character. +All other characters are copied to ARGUMENT(s) verbatim. + +The conversion specifiers are: + +FLAG(%a, the current locales abbreviated weekday name) +FLAG(%A, the current locales full weekday name) +FLAG(%b, the current locales abbreviated month name) +FLAG(%B, the current locales full month name) +FLAG(%c, the current locales date and time representation) +FLAG(%d, the day of the month (in the range (01,31))) +FLAG(%H, the hour (in the range (00,23))) +FLAG(%I, the hour (in the range (01,12))) +FLAG(%j, the day of the year (in the range (001,366))) +FLAG(%m, the numeric month (in the range (01,12))) +FLAG(%M, the minute (in the range (00,59))) +FLAG(%p, the current locales AM/PM designator) +FLAG(%S, the second (in the range (00,61))) +FLAG(%U, the week of the year (Sunday based, in the range (00,53))) +FLAG(%w, the numeric weekday (in the range (0,6), with Sunday as 0)) +FLAG(%W, the week of the year (Monday based, in the range (00,53))) +FLAG(%x, the current locales date representation) +FLAG(%X, the current locales time representation) +FLAG(%y, the year without centruy (in the range (00,99))) +FLAG(%Y, the year with century) +FLAG(%Z, the time zone name or abbreviation, if determinable) +FLAG(%%, a literal %) +***/ + +/* +UNDEFINED(Copying takes place between objects that overlap) +LC_TIME +RETURN_FAILURE(ZERO) +RETURN_SUCCESS(the length of the converted string, not counting the terminating null) +*/ + +/* +STDC(1) +*/ |