1: #include <sys/types.h>
   2: #include <time.h>
   3: #include <stdio.h>
   4: /*
   5:  * Convert a ctime(3) format string into a system format date.
   6:  * Return the date thus calculated.
   7:  *
   8:  * Return -1 if the string is not in ctime format.
   9:  */
  10: 
  11: /*
  12:  * Offsets into the ctime string to various parts.
  13:  */
  14: 
  15: #define E_MONTH     4
  16: #define E_DAY       8
  17: #define E_HOUR      11
  18: #define E_MINUTE    14
  19: #define E_SECOND    17
  20: #define E_YEAR      20
  21: 
  22: time_t unctime(str)
  23:     char *str;
  24: {
  25:     struct tm then;
  26:     char dbuf[30];
  27:     time_t emitl();
  28: 
  29:     if (strlen(str) != 25)
  30:         str[25] = 0;
  31:     strcpy(dbuf, str);
  32:     dbuf[E_MONTH+3] = 0;
  33:     if ( (then.tm_mon = lookup(&dbuf[E_MONTH])) < 0) {
  34:         return(-1);;
  35:     }
  36:     then.tm_mday = atoi(&dbuf[E_DAY]);
  37:     then.tm_hour = atoi(&dbuf[E_HOUR]);
  38:     then.tm_min = atoi(&dbuf[E_MINUTE]);
  39:     then.tm_sec = atoi(&dbuf[E_SECOND]);
  40:     then.tm_year = atoi(&dbuf[E_YEAR]) - 1900;
  41:     return(emitl(&then));
  42: }
  43: 
  44: static char months[] =
  45:     "JanFebMarAprMayJunJulAugSepOctNovDec";
  46: 
  47: static
  48: lookup(str)
  49:     char *str;
  50: {
  51:     register char *cp, *cp2;
  52: 
  53:     for (cp = months, cp2 = str; *cp != 0; cp += 3)
  54:         if (strncmp(cp, cp2, 3) == 0)
  55:             return((cp-months) / 3);
  56:     return(-1);
  57: }
  58: /*
  59:  * Routine to convert a localtime(3) format date back into
  60:  * a system format date.
  61:  *
  62:  *	Use a binary search.
  63:  */
  64: 
  65: struct tm *localtime();
  66: 
  67: time_t emitl(dp)
  68:     struct tm *dp;
  69: {
  70:     time_t conv, bit;
  71:     register int i;
  72:     struct tm dcopy;
  73: 
  74:     dcopy = *dp;
  75:     dp = &dcopy;
  76:     conv = 0;
  77:     for (i = 30; i >= 0; i--) {
  78:         bit = 1L << i;
  79:         conv |= bit;
  80:         if (dcmp(localtime(&conv), dp) > 0)
  81:             conv &= ~bit;
  82:     }
  83:     return(conv);
  84: }
  85: 
  86: /*
  87:  * Compare two localtime dates, return result.
  88:  */
  89: 
  90: #define DECIDE(a) \
  91:     if (dp->a > dp2->a) \
  92:         return(1); \
  93:     if (dp->a < dp2->a) \
  94:         return(-1)
  95: 
  96: static
  97: dcmp(dp, dp2)
  98:     register struct tm *dp, *dp2;
  99: {
 100: 
 101:     DECIDE(tm_year);
 102:     DECIDE(tm_mon);
 103:     DECIDE(tm_mday);
 104:     DECIDE(tm_hour);
 105:     DECIDE(tm_min);
 106:     DECIDE(tm_sec);
 107:     return(0);
 108: }
 109: static  char *sccsid = "@(#)unctime.c	1.3 (Berkeley) 81/04/18";

Defined functions

dcmp defined in line 96; used 1 times
  • in line 80
emitl defined in line 67; used 2 times
lookup defined in line 47; used 1 times
  • in line 33
unctime defined in line 22; used 2 times

Defined variables

months defined in line 44; used 2 times
sccsid defined in line 109; never used

Defined macros

DECIDE defined in line 90; used 6 times
E_DAY defined in line 16; used 1 times
  • in line 36
E_HOUR defined in line 17; used 1 times
  • in line 37
E_MINUTE defined in line 18; used 1 times
  • in line 38
E_MONTH defined in line 15; used 2 times
E_SECOND defined in line 19; used 1 times
  • in line 39
E_YEAR defined in line 20; used 1 times
  • in line 40
Last modified: 1988-12-25
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