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-rw-r--r--toys/date.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/toys/date.c b/toys/date.c
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+/* vi: set sw=4 ts=4:
+ *
+ * date.c - set/get the date
+ *
+ * Copyright 2012 Andre Renaud <andre@bluewatersys.com>
+ *
+ * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/date.html
+
+USE_DATE(NEWTOY(date, "u", TOYFLAG_BIN))
+
+config DATE
+ bool "date"
+ default y
+ help
+ usage: date [-u] [+format] | mmddhhmm[[cc]yy]
+
+ Set/get the current date/time
+*/
+
+#include "toys.h"
+
+/* Convert a string of decimal numbers to their integer equivalent */
+static int fromdec(const char *buf, int len)
+{
+ int result = 0;
+ while (len--)
+ result=result * 10 + (*buf++ - '0');
+ return result;
+}
+
+void date_main(void)
+{
+ const char *format_string = "%a %b %e %H:%M:%S %Z %Y";
+
+ /* Check if we should be displaying the date */
+ if (!toys.optargs[0] || toys.optargs[0][0] == '+') {
+ time_t now = time(NULL);
+ struct tm *tm;
+ if (toys.optargs[0])
+ format_string = &toys.optargs[0][1];
+ if (toys.optflags)
+ tm = gmtime(&now);
+ else
+ tm = localtime(&now);
+ if (!tm)
+ perror_msg("Unable to retrieve current time");
+ if (!strftime(toybuf, sizeof(toybuf), format_string, tm))
+ perror_msg("invalid format string `%s'", format_string);
+ puts(toybuf);
+ } else {
+ int len = strlen(toys.optargs[0]);
+ struct tm tm;
+ struct timeval tv;
+
+ if (len < 8 || len > 12 || len & 1)
+ error_msg("invalid date `%s'", toys.optargs[0]);
+ memset(&tm, 0, sizeof(tm));
+ /* Date format: mmddhhmm[[cc]yy] */
+ tm.tm_mon = fromdec(toys.optargs[0], 2) - 1;
+ tm.tm_mday = fromdec(&toys.optargs[0][2], 2);
+ tm.tm_hour = fromdec(&toys.optargs[0][4], 2);
+ tm.tm_min = fromdec(&toys.optargs[0][6], 2);
+ if (len == 12)
+ tm.tm_year = fromdec(&toys.optargs[0][8], 4) - 1900;
+ else if (len == 10) {
+ tm.tm_year = fromdec(&toys.optargs[0][8], 2);
+ /* 69-99 = 1969-1999, 0 - 68 = 2000-2068 */
+ if (tm.tm_year < 69)
+ tm.tm_year += 100;
+ } else {
+ /* Year not specified, so retrieve current year */
+ time_t now = time(NULL);
+ struct tm *now_tm = localtime(&now);
+ if (!now_tm)
+ perror_msg("Unable to retrieve current time");
+ tm.tm_year = now_tm->tm_year;
+ }
+ if (!toys.optflags)
+ tv.tv_sec = mktime(&tm);
+ else {
+ /* Get the UTC version of a struct tm */
+ char *tz = NULL;
+ tz = getenv("TZ");
+ setenv("TZ", "", 1);
+ tzset();
+ tv.tv_sec = mktime(&tm);
+ if (tz)
+ setenv("TZ", tz, 1);
+ else
+ unsetenv("TZ");
+ tzset();
+ }
+
+ if (tv.tv_sec == (time_t)-1)
+ error_msg("invalid date `%s'", toys.optargs[0]);
+ tv.tv_usec = 0;
+ if (!strftime(toybuf, sizeof(toybuf), format_string, &tm))
+ perror_msg("invalid format string `%s'", format_string);
+ puts(toybuf);
+ if (settimeofday(&tv, NULL) < 0)
+ perror_msg("cannot set date");
+ }
+}