Add date command by Andre Renaud.

1 files changed, 103 insertions, 0 deletions

diff --git a/toys/date.c b/toys/date.c
new file mode 100644
index 00000000..ebcdeb1f
--- /dev/null
+++ b/toys/date.c
@@ -0,0 +1,103 @@
+/* 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");
+    }
+}