Add clock command

1 files changed, 110 insertions, 0 deletions

diff --git a/jim-clock.c b/jim-clock.c
new file mode 100644
index 0000000..fb3c433
--- /dev/null
+++ b/jim-clock.c
@@ -0,0 +1,110 @@
+/*
+ * tcl_clock.c
+ *
+ * Implements the clock command
+ */
+
+/* For strptime() */
+#define _XOPEN_SOURCE
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <time.h>
+
+#include "jim.h"
+#include "jim-subcmd.h"
+
+static int clock_cmd_format(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    /* How big is big enough? */
+    char buf[100];
+    time_t t;
+    long seconds;
+
+    const char *format = "%a %b  %d %H:%M:%S %Z %Y";
+
+    if (argc == 2 || (argc == 3 && !Jim_CompareStringImmediate(interp, argv[1], "-format"))) {
+        return -1;
+    }
+
+    if (argc == 3) {
+        format = Jim_GetString(argv[2], NULL);
+    }
+
+    if (Jim_GetLong(interp, argv[0], &seconds) != JIM_OK) {
+        return JIM_ERR;
+    }
+    t = seconds;
+
+    strftime(buf, sizeof(buf), format, localtime(&t));
+
+    Jim_SetResultString(interp, buf, -1);
+
+    return JIM_OK;
+}
+
+static int clock_cmd_scan(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    char *pt;
+    struct tm tm;
+    time_t now = time(0);
+    
+    if (!Jim_CompareStringImmediate(interp, argv[1], "-format")) {
+        return -1;
+    }
+
+    /* Initialise with the current date/time */
+    tm = *localtime(&now);
+
+    pt = strptime(Jim_GetString(argv[0], NULL), Jim_GetString(argv[2], NULL), &tm);
+    if (pt == 0 || *pt != 0) {
+        Jim_SetResultString(interp, "Failed to parse time according to format", -1);
+        return JIM_ERR;
+    }
+
+    /* Now convert into a time_t */
+    Jim_SetResult(interp, Jim_NewIntObj(interp, (jim_wide)mktime(&tm)));
+
+    return JIM_OK;
+}
+
+static int clock_cmd_seconds(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    Jim_SetResult(interp, Jim_NewIntObj(interp, (jim_wide)time(NULL)));
+
+    return JIM_OK;
+}
+
+static const jim_subcmd_type command_table[] = {
+    {   .cmd = "seconds",
+        .function = clock_cmd_seconds,
+        .minargs = 0,
+        .maxargs = 0,
+        .description = "Returns the current time as seconds since the epoch"
+    },
+    {   .cmd = "format",
+        .args = "seconds ?-format format?",
+        .function = clock_cmd_format,
+        .minargs = 1,
+        .maxargs = 3,
+        .description = "Format the given time"
+    },
+    {   .cmd = "scan",
+        .args = "str -format format",
+        .function = clock_cmd_scan,
+        .minargs = 3,
+        .maxargs = 3,
+        .description = "Determine the time according to the given format"
+    },
+    { 0 }
+};
+
+int Jim_ClockInit(Jim_Interp *interp)
+{
+    if (Jim_PackageProvide(interp, "clock", "1.0", JIM_ERRMSG) != JIM_OK) {
+        return JIM_ERR;
+    }
+    Jim_CreateCommand(interp, "clock", Jim_SubCmdProc, (void *)command_table, NULL);
+    return JIM_OK;
+}