/* * Project : tin - a Usenet reader * Module : strftime.c * Author : A. Robbins & I. Lea * Created : 1991-02-01 * Updated : 2024-12-17 * Notes : Relatively quick-and-dirty implementation of ANSI library * routine for System V Unix systems. * If target system already has strftime() call the #define * HAVE_STRFTIME can be set to use it. * TODO: "sync" against * * Example : time(&secs); * tm = localtime(&secs); * num = strftime(buf, sizeof(buf), "%a %d-%m-%y %H:%M:%S", tm); * * Copyright (c) 1991-2026 Arnold Robbins * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. Neither the name of the copyright holder nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef TIN_H # include "tin.h" #endif /* !TIN_H */ #ifndef HAVE_STRFTIME # define SYSV_EXT 1 /* stuff in System V ascftime routine */ #endif /* !HAVE_STRFTIME */ /* * strftime --- produce formatted time */ size_t my_strftime( char *s, size_t maxsize, const char *format, const struct tm *timeptr) { #ifdef HAVE_STRFTIME return strftime(s, maxsize, format, timeptr); #else char *endp; char *start = s; char tbuf[100]; int i; static const char *days_a[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", }; static const char *days_l[] = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", }; static const char *months_a[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec", }; static const char *months_l[] = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December", }; static const char *ampm[] = { "AM", "PM", }; if (s == NULL || format == NULL || timeptr == NULL || maxsize == 0) return 0; if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize) return 0; # ifdef HAVE_TZSET tzset(); # else # ifdef HAVE_SETTZ settz(); # endif /* HAVE_SETTZ */ # endif /* HAVE_TZSET */ endp = s + maxsize; for (; *format && s < endp - 1; format++) { tbuf[0] = '\0'; if (*format != '%') { *s++ = *format; continue; } switch (*++format) { case '\0': *s++ = '%'; goto out; case '%': *s++ = '%'; continue; case 'a': /* abbreviated weekday name */ strcpy(tbuf, days_a[timeptr->tm_wday]); break; case 'A': /* full weekday name */ strcpy(tbuf, days_l[timeptr->tm_wday]); break; # ifdef SYSV_EXT case 'h': /* abbreviated month name */ # endif /* SYSV_EXT */ case 'b': /* abbreviated month name */ strcpy(tbuf, months_a[timeptr->tm_mon]); break; case 'B': /* full month name */ strcpy(tbuf, months_l[timeptr->tm_mon]); break; case 'c': /* appropriate date and time representation */ snprintf(tbuf, sizeof(tbuf), "%s %s %2d %02d:%02d:%02d %d", days_a[timeptr->tm_wday], months_a[timeptr->tm_mon], timeptr->tm_mday, timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec, timeptr->tm_year + 1900); break; case 'd': /* day of the month, 01 - 31 */ snprintf(tbuf, sizeof(tbuf), "%02d", timeptr->tm_mday); break; case 'H': /* hour, 24-hour clock, 00 - 23 */ snprintf(tbuf, sizeof(tbuf), "%02d", timeptr->tm_hour); break; case 'I': /* hour, 12-hour clock, 01 - 12 */ i = timeptr->tm_hour; if (i == 0) i = 12; else if (i > 12) i -= 12; snprintf(tbuf, sizeof(tbuf), "%02d", i); break; case 'j': /* day of the year, 001 - 366 */ snprintf(tbuf, sizeof(tbuf), "%03d", timeptr->tm_yday + 1); break; case 'm': /* month, 01 - 12 */ snprintf(tbuf, sizeof(tbuf), "%02d", timeptr->tm_mon + 1); break; case 'M': /* minute, 00 - 59 */ snprintf(tbuf, sizeof(tbuf), "%02d", timeptr->tm_min); break; case 'p': /* AM or PM based on 12-hour clock */ strcpy(tbuf, ampm[((timeptr->tm_hour < 12) ? 0 : 1)]); break; case 'S': /* second, 00 - 61 */ snprintf(tbuf, sizeof(tbuf), "%02d", timeptr->tm_sec); break; case 'w': /* weekday, Sunday == 0, 0 - 6 */ snprintf(tbuf, sizeof(tbuf), "%d", timeptr->tm_wday); break; case 'x': /* appropriate date representation */ snprintf(tbuf, sizeof(tbuf), "%s %s %2d %d", days_a[timeptr->tm_wday], months_a[timeptr->tm_mon], timeptr->tm_mday, timeptr->tm_year + 1900); break; case 'X': /* appropriate time representation */ snprintf(tbuf, sizeof(tbuf), "%02d:%02d:%02d", timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec); break; case 'y': /* year without a century, 00 - 99 */ i = timeptr->tm_year % 100; snprintf(tbuf, sizeof(tbuf), "%d", i); break; case 'Y': /* year with century */ snprintf(tbuf, sizeof(tbuf), "%d", timeptr->tm_year + 1900); break; # ifdef SYSV_EXT case 'n': /* same as \n */ tbuf[0] = '\n'; tbuf[1] = '\0'; break; case 't': /* same as \t */ tbuf[0] = '\t'; tbuf[1] = '\0'; break; case 'D': /* date as %m/%d/%y */ my_strftime(tbuf, sizeof(tbuf), "%m/%d/%y", timeptr); break; case 'e': /* day of month, blank padded */ snprintf(tbuf, sizeof(tbuf), "%2d", timeptr->tm_mday); break; case 'r': /* time as %I:%M:%S %p */ my_strftime(tbuf, sizeof(tbuf), "%I:%M:%S %p", timeptr); break; case 'R': /* time as %H:%M */ my_strftime(tbuf, sizeof(tbuf), "%H:%M", timeptr); break; case 'T': /* time as %H:%M:%S */ my_strftime(tbuf, sizeof(tbuf), "%H:%M:%S", timeptr); break; # endif /* SYSV_EXT */ case 'C': /* century number (SU) */ sprintf(tbuf, "%02d", (timeptr->tm_year + 1900) / 100); break; case 'F': /* ISO 8601 date format (C99) */ my_strftime(tbuf, sizeof(tbuf), "%Y-%m-%d", timeptr); break; case 'k': /* 24-hour clock, blank padded */ snprintf(tbuf, sizeof(tbuf), "%2d", timeptr->tm_hour); break; case 'l': /* 12-hour clock, blank padded */ if ((i = timeptr->tm_hour) == 0) i = 12; else if (i > 12) i -= 12; snprintf(tbuf, sizeof(tbuf), "%2d", i); break; case 'P': /* am or pm based on 12-hour clock (GNU) */ strcpy(tbuf, ampm[((timeptr->tm_hour < 12) ? 0 : 1)]); str_lwr(tbuf); break; case 's': /* seconds since the Epoch */ sprintf(tbuf, "%ld", time((time_t *) 0)); break; case 'u': /* day of the week, range 1 to 7 */ sprintf(tbuf, "%d", timeptr->tm_wday == 0 ? 7 : timeptr->tm_wday); break; default: tbuf[0] = '%'; tbuf[1] = *format; tbuf[2] = '\0'; break; } if ((i = strlen(tbuf))) { if (s + i < endp - 1) { strcpy(s, tbuf); s += i; } else return 0; } } out: if (s < endp && *format == '\0') { *s = '\0'; return (size_t) (s - start); } else return 0; #endif /* HAVE_STRFTIME */ }