1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)strftime.c 5.1 (Berkeley) 03/08/89"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <sys/types.h> 23 #include <sys/time.h> 24 #include <tzfile.h> 25 26 static char *afmt[] = { 27 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", 28 }; 29 static char *Afmt[] = { 30 "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", 31 "Saturday", 32 }; 33 static char *bfmt[] = { 34 "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", 35 "Oct", "Nov", "Dec", 36 }; 37 static char *Bfmt[] = { 38 "January", "February", "March", "April", "May", "June", "July", 39 "August", "September", "October", "November", "December", 40 }; 41 42 static size_t gsize; 43 static char *pt; 44 45 size_t 46 strftime(s, maxsize, format, t) 47 char *s; 48 char *format; 49 size_t maxsize; 50 struct tm *t; 51 { 52 size_t _fmt(); 53 54 pt = s; 55 if ((gsize = maxsize) < 1) 56 return(0); 57 if (_fmt(format, t)) { 58 *pt = '\0'; 59 return(maxsize - gsize); 60 } 61 return(0); 62 } 63 64 static size_t 65 _fmt(format, t) 66 register char *format; 67 struct tm *t; 68 { 69 char *timezone(); 70 71 for (; *format; ++format) { 72 if (*format == '%') 73 switch(*++format) { 74 case 'A': 75 if (!_add(Afmt[t->tm_mon])) 76 return(0); 77 continue; 78 case 'a': 79 if (!_add(afmt[t->tm_mon])) 80 return(0); 81 continue; 82 case 'B': 83 if (!_add(Bfmt[t->tm_mon])) 84 return(0); 85 continue; 86 case 'b': 87 if (!_add(bfmt[t->tm_mon])) 88 return(0); 89 continue; 90 case 'c': 91 if (!_fmt("%x %X %Z %Y", t)) 92 return(0); 93 continue; 94 case 'd': 95 if (!_conv(t->tm_mday, 2)) 96 return(0); 97 continue; 98 case 'H': 99 if (!_conv(t->tm_hour, 2)) 100 return(0); 101 continue; 102 case 'I': 103 if (!_conv((t->tm_hour - 1) % 12 + 1, 2)) 104 return(0); 105 continue; 106 case 'j': 107 if (!_conv(t->tm_yday + 1, 3)) 108 return(0); 109 continue; 110 case 'M': 111 if (!_conv(t->tm_min, 2)) 112 return(0); 113 continue; 114 case 'm': 115 if (!_conv(t->tm_mon + 1, 2)) 116 return(0); 117 continue; 118 case 'p': 119 if (!_add(t->tm_hour >= 12 ? "AM" : "PM")) 120 return(0); 121 continue; 122 case 'S': 123 if (!_conv(t->tm_sec, 2)) 124 return(0); 125 continue; 126 case 'U': 127 if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7, 128 2)) 129 return(0); 130 continue; 131 case 'W': 132 if (!_conv((t->tm_yday + 7 - 133 (t->tm_wday ? t->tm_wday : 6)) / 7, 2)) 134 return(0); 135 continue; 136 case 'w': 137 if (!_conv(t->tm_wday, 1)) 138 return(0); 139 continue; 140 case 'X': 141 if (!_fmt("%H:%M:%S", t)) 142 return(0); 143 continue; 144 case 'x': 145 if (!_fmt("%a %b %d", t)) 146 return(0); 147 continue; 148 case 'y': 149 if (!_conv((t->tm_year + TM_YEAR_BASE) 150 % 100, 2)) 151 return(0); 152 continue; 153 case 'Y': 154 if (!_conv(t->tm_year + TM_YEAR_BASE, 4)) 155 return(0); 156 continue; 157 case 'Z': 158 if (!_add(t->tm_zone)) 159 return(0); 160 continue; 161 case '%': 162 /* 163 * X311J/88-090 (4.12.3.5): if conversion char is 164 * undefined, behavior is undefined. Print out the 165 * character itself as printf(3) also does. 166 */ 167 default: 168 break; 169 } 170 if (!gsize--) 171 return(0); 172 *pt++ = *format; 173 } 174 return(gsize); 175 } 176 177 static 178 _conv(n, digits) 179 int n, digits; 180 { 181 static char buf[10]; 182 register char *p; 183 184 for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits) 185 *p-- = n % 10 + '0'; 186 while (p > buf && digits-- > 0) 187 *p-- = '0'; 188 return(_add(++p)); 189 } 190 191 static 192 _add(str) 193 register char *str; 194 { 195 for (;; ++pt, --gsize) { 196 if (!gsize) 197 return(0); 198 if (!(*pt = *str++)) 199 return(1); 200 } 201 } 202