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-rw-r--r--date.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/date.c b/date.c
new file mode 100644
index 000000000..1e43936f8
--- /dev/null
+++ b/date.c
@@ -0,0 +1,184 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <time.h>
+
+static time_t my_mktime(struct tm *tm)
+{
+ static const int mdays[] = {
+ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
+ };
+ int year = tm->tm_year - 70;
+ int month = tm->tm_mon;
+ int day = tm->tm_mday;
+
+ if (year < 0 || year > 129) /* algo only works for 1970-2099 */
+ return -1;
+ if (month < 0 || month > 11) /* array bounds */
+ return -1;
+ if (month < 2 || (year + 2) % 4)
+ day--;
+ return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
+ tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
+}
+
+static const char *month_names[] = {
+ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+};
+
+static const char *weekday_names[] = {
+ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+};
+
+
+static char *skipfws(char *str)
+{
+ while (isspace(*str))
+ str++;
+ return str;
+}
+
+
+/* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
+ (i.e. English) day/month names, and it doesn't work correctly with %z. */
+void parse_date(char *date, char *result, int maxlen)
+{
+ struct tm tm;
+ char *p, *tz;
+ int i, offset;
+ time_t then;
+
+ memset(&tm, 0, sizeof(tm));
+
+ /* Skip day-name */
+ p = skipfws(date);
+ if (!isdigit(*p)) {
+ for (i=0; i<7; i++) {
+ if (!strncmp(p,weekday_names[i],3) && p[3] == ',') {
+ p = skipfws(p+4);
+ goto day;
+ }
+ }
+ return;
+ }
+
+ /* day */
+ day:
+ tm.tm_mday = strtoul(p, &p, 10);
+
+ if (tm.tm_mday < 1 || tm.tm_mday > 31)
+ return;
+
+ if (!isspace(*p))
+ return;
+
+ p = skipfws(p);
+
+ /* month */
+
+ for (i=0; i<12; i++) {
+ if (!strncmp(p, month_names[i], 3) && isspace(p[3])) {
+ tm.tm_mon = i;
+ p = skipfws(p+strlen(month_names[i]));
+ goto year;
+ }
+ }
+ return; /* Error -- bad month */
+
+ /* year */
+ year:
+ tm.tm_year = strtoul(p, &p, 10);
+
+ if (!tm.tm_year && !isspace(*p))
+ return;
+
+ if (tm.tm_year > 1900)
+ tm.tm_year -= 1900;
+
+ p=skipfws(p);
+
+ /* hour */
+ if (!isdigit(*p))
+ return;
+ tm.tm_hour = strtoul(p, &p, 10);
+
+ if (tm.tm_hour > 23)
+ return;
+
+ if (*p != ':')
+ return; /* Error -- bad time */
+ p++;
+
+ /* minute */
+ if (!isdigit(*p))
+ return;
+ tm.tm_min = strtoul(p, &p, 10);
+
+ if (tm.tm_min > 59)
+ return;
+
+ if (*p != ':')
+ goto zone;
+ p++;
+
+ /* second */
+ if (!isdigit(*p))
+ return;
+ tm.tm_sec = strtoul(p, &p, 10);
+
+ if (tm.tm_sec > 60)
+ return;
+
+ zone:
+ if (!isspace(*p))
+ return;
+
+ p = skipfws(p);
+
+ if (*p == '-')
+ offset = -60;
+ else if (*p == '+')
+ offset = 60;
+ else
+ return;
+
+ if (!isdigit(p[1]) || !isdigit(p[2]) || !isdigit(p[3]) || !isdigit(p[4]))
+ return;
+
+ tz = p;
+ i = strtoul(p+1, NULL, 10);
+ offset *= ((i % 100) + ((i / 100) * 60));
+
+ p = skipfws(p + 5);
+ if (*p && *p != '(') /* trailing comment like (EDT) is ok */
+ return;
+
+ then = my_mktime(&tm); /* mktime uses local timezone */
+ if (then == -1)
+ return;
+
+ then -= offset;
+
+ snprintf(result, maxlen, "%lu %5.5s", then, tz);
+}
+
+void datestamp(char *buf, int bufsize)
+{
+ time_t now;
+ int offset;
+
+ time(&now);
+
+ offset = my_mktime(localtime(&now)) - now;
+ offset /= 60;
+
+ snprintf(buf, bufsize, "%lu %+05d", now, offset/60*100 + offset%60);
+}