Usermode/libc - Improved strerror, added some basic time functions

[tpg/acess2.git] / Usermode / Libraries / libc.so_src / time.c

diff --git a/Usermode/Libraries/libc.so_src/time.c b/Usermode/Libraries/libc.so_src/time.c
index aa4b2de..412475b 100644 (file)
--- a/Usermode/Libraries/libc.so_src/time.c
+++ b/Usermode/Libraries/libc.so_src/time.c
@@ -7,6 +7,7 @@
  */
 #include <time.h>
 #include <acess/sys.h>
+#include <string.h>
 
 clock_t clock(void)
 {
@@ -20,3 +21,71 @@ time_t time(time_t *t)
                *t = ret;
        return ret;
 }
+
+static struct tm       static_tm;
+
+struct tm *localtime(const time_t *timer)
+{
+       struct tm *ret = &static_tm;
+
+       // TODO: This breaks on negative timestamps
+
+       int64_t day = *timer / (1000*60*60*24);
+       int64_t iday = *timer % (1000*60*60*24);        
+
+       ret->tm_sec = (iday / 1000) % 60;;
+       ret->tm_min = (iday / (1000*60)) % 60;
+       ret->tm_hour = (iday / (1000*60*60));
+       ret->tm_year = 0;
+       ret->tm_mon = 0;
+       ret->tm_mday = 0;
+       ret->tm_wday = (day + 6) % 7;   // 1 Jan 2000 was a saturday
+       ret->tm_yday = 0;
+       ret->tm_isdst = 0;      // Fuck DST
+       return ret;
+}
+
+static inline size_t MIN(size_t a, size_t b) { return a < b ? a : b; }
+static size_t _puts(char * restrict s, size_t maxsize, size_t ofs, const char *str, size_t len)
+{
+       if( s && ofs < maxsize ) {
+               size_t  addlen = MIN(len, maxsize-1-ofs);
+               memcpy(s+ofs, str, addlen);
+       }
+       return len;
+}
+
+size_t strftime(char*restrict s, size_t maxsize, const char*restrict format, const struct tm*restrict timeptr)
+{
+       size_t  ofs = 0;
+
+       while( *format )
+       {
+               const char *restrict start = format;
+               while( *format && *format != '%' )
+                       format ++;
+               if( format != start )
+                       ofs += _puts(s, maxsize, ofs, start, format-start);
+               if( *format == 0 )
+                       break;
+               format ++;
+               switch(*format++)
+               {
+               case 0: format--;       break;
+               case '%':       ofs += _puts(s, maxsize, ofs, format-1, 1);     break;
+               case 'd':       // The day of the month as a decimal number (range 01 to 31).
+                       {
+                       char tmp[2] = {'0','0'};
+                       tmp[0] += (timeptr->tm_mday / 10) % 10;
+                       tmp[1] += timeptr->tm_mday % 10;
+                       ofs += _puts(s, maxsize, ofs, tmp, 2);
+                       }
+                       break;
+               default:
+                       _SysDebug("TODO: strftime('...%%%c...')", format[-1]);
+                       break;
+               }
+       }
+       
+       return ofs;
+}