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-rw-r--r--kernel/src/time.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/kernel/src/time.c b/kernel/src/time.c
new file mode 100644
index 0000000..e949882
--- /dev/null
+++ b/kernel/src/time.c
@@ -0,0 +1,144 @@
+#include <string.h>
+#include <time.h>
+
+static char* ABB_WEEKDAY[7] = {
+ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+};
+
+static char* FULL_WEEKDAY[7] = {
+ "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturady"
+};
+
+static char* ABB_MONTH[12] = {
+ "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+};
+
+static char* FULL_MONTH[12] = {
+ "January", "Feburary", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
+};
+
+static char *write_num(unsigned int num, unsigned int pad, char *buf, size_t n) {
+ size_t digits = 1;
+ unsigned int x = num;
+
+ while (x /= 10, x > 0) digits++;
+ if (pad == 0) pad = digits;
+
+ for (size_t i = 0; i < pad; i++) {
+
+ size_t digit;
+ if (i >= digits) {
+ digit = 0;
+ } else {
+ digit = num % 10;
+ num /= 10;
+ }
+
+ if (pad - i - 1 >= n) continue;
+ buf[pad - i - 1] = '0' + digit;
+
+ }
+
+ if (pad > n) pad = n;
+
+ return buf + pad;
+}
+
+void timetostr(struct Time *time, char *format, char *buf, size_t n) {
+ char *index = buf;
+ char c;
+ int space;
+
+ while (
+ c = *format++,
+ space = (buf + n) - index,
+ c != '\0' && space > 0
+ ) {
+ if (c != '%') {
+ *index++ = c;
+ continue;
+ } else {
+ c = *format++;
+ }
+
+ switch (c) {
+ case '%':
+ *index++ = '%';
+ break;
+ case 'a':
+ index = strncpy(index, ABB_WEEKDAY[time->wday], space);
+ break;
+ case 'A':
+ index = strncpy(index, FULL_WEEKDAY[time->wday], space);
+ break;
+ case 'b':
+ case 'h':
+ index = strncpy(index, ABB_MONTH[time->mon], space);
+ break;
+ case 'B':
+ index = strncpy(index, FULL_MONTH[time->mon], space);
+ break;
+ case 'C':
+ index = write_num(time->cen, 0, index, space);
+ break;
+ case 'd':
+ index = write_num(time->mday, 2, index, space);
+ break;
+ case 'H':
+ index = write_num(time->hour, 2, index, space);
+ break;
+ case 'I':
+ index = write_num((time->hour + 12) % 12 + 1, 2, index, space);
+ break;
+ case 'j':
+ index = write_num(time->yday, 3, index, space);
+ break;
+ case 'm':
+ index = write_num(time->mon + 1, 2, index, space);
+ break;
+ case 'M':
+ index = write_num(time->min, 2, index, space);
+ break;
+ case 'n':
+ *index++ = '\n';
+ break;
+ case 'p':
+ index = strncpy(index, time->hour > 11 ? "PM" : "AM", space);
+ break;
+ case 'P':
+ index = strncpy(index, time->hour > 11 ? "pm" : "am", space);
+ break;
+ case 'q':
+ index = write_num((time->mon + 3) / 3, 0, index, space);
+ break;
+ case 'S':
+ index = write_num(time->sec, 2, index, space);
+ break;
+ case 't':
+ *index++ = '\t';
+ break;
+ case 'u':
+ index = write_num(((time->wday + 1 )% 7) + 1, 0, index, space);
+ break;
+ case 'w':
+ index = write_num(time->wday, 0, index, space);
+ break;
+ case 'y':
+ index = write_num(time->yn, 2, index, space);
+ break;
+ case 'Y':
+ index = write_num(time->year + 1900, 0, index, space);
+ break;
+ default: {
+ char b[3] = {'%', c, '\0'};
+ index = strncpy(index, b, space);
+ break;
+ }
+ }
+ }
+
+ if (space < 1)
+ buf[n - 1] = '\0';
+ else
+ *index = '\0';
+}