Wish me luck getting to sleep this century

bin/can2dump.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
+#include <getopt.h>
 #include <inttypes.h>
 #include <fcntl.h>
 
@@ -10,8 +11,16 @@
 
 #include "can2dump.h"
 
+enum timestamp_type {
+    TIMESTAMP_NONE,
+    TIMESTAMP_ABSOLUTE,
+    TIMESTAMP_DELTA,
+    TIMESTAMP_ZERO,
+    TIMESTAMP_DATE
+};
+
 char *hexagram_arglist_can2dump(void) {
-    return "ifname [file.can] [candump.txt]";
+    return "[--timestamp=|adzA|] ifname [file.can] [candump.txt]";
 }
 
 static int usage(int argc, char **argv, const char *message, ...) {
@@ -20,6 +29,7 @@ static int usage(int argc, char **argv, const char *message, ...) {
 
         va_start(args, message);
         vfprintf(stderr, message, args);
+         fprintf(stderr, "\n");
         va_end(args);
     }
 
@@ -36,13 +46,48 @@ int hexagram_main_can2dump(int argc, char **argv) {
     struct timeval timestamp;
     struct can_frame frame;
 
-    if (argc <= 1) {
+    static struct option opts[] = {
+        { "timestamp", required_argument, NULL, 't' },
+        { NULL,        0,                 NULL, 0   }
+    };
+
+    enum timestamp_type tstype = TIMESTAMP_NONE;
+
+    int argn;
+    char **args;
+
+    int ch;
+
+    while ((ch = getopt_long(argc, argv, "t:", opts, NULL)) >= 0) {
+        switch (ch) {
+            case 't':
+                switch (optarg[0]) {
+                    case 'a': tstype = TIMESTAMP_ABSOLUTE; break;
+                    case 'd': tstype = TIMESTAMP_DELTA;    break;
+                    case 'z': tstype = TIMESTAMP_ZERO;     break;
+                    case 'A': tstype = TIMESTAMP_DATE;     break;
+
+                    default:
+                        return usage(argc, argv, "Invalid timestamp type");
+                }
+
+                break;
+
+            default:
+                return usage(argc, argv, "Unknown flag '%c'", ch);
+        }
+    }
+
+    argn = argc - optind;
+    args = argv + optind;
+
+    if (argn == 0) {
         return usage(argc, argv, "No CAN interface name provided");
     }
 
-    ifname = argv[1];
+    ifname = args[0];
 
-    if (argc == 2) {
+    if (argn == 1) {
         if ((capture = hexagram_capture_open_fd(fileno(stdin), O_RDONLY)) == NULL) {
             perror("hexagram_capture_open_fd()");
 
@@ -50,33 +95,43 @@ int hexagram_main_can2dump(int argc, char **argv) {
         }
 
         fh = stdout;
-    } else if (argc == 3) {
-        if ((capture = hexagram_capture_open_file(argv[2], O_RDONLY)) == NULL) {
+    } else if (argn == 2) {
+        if ((capture = hexagram_capture_open_file(args[1], O_RDONLY)) == NULL) {
             perror("hexagram_capture_open_file()");
 
             goto error_capture_open;
         }
 
         fh = stdout;
-    } else if (argc == 4) {
-        if ((capture = hexagram_capture_open_file(argv[2], O_RDONLY)) == NULL) {
+    } else if (argn == 3) {
+        if ((capture = hexagram_capture_open_file(args[1], O_RDONLY)) == NULL) {
             perror("hexagram_capture_open_file()");
 
             goto error_capture_open;
         }
 
-        if ((fh = fopen(argv[3], "w")) == NULL) {
+        if ((fh = fopen(args[2], "w")) == NULL) {
             goto error_fopen;
         }
     } else {
-        usage(argc, argv, NULL);
-        exit(1);
+        return usage(argc, argv, NULL);
     }
 
     while (hexagram_capture_read(capture, &timestamp, &frame) >= 0) {
         uint8_t i;
 
-        fprintf(fh, "%7s  %03X   [%d] ",
+        switch (tstype) {
+            case TIMESTAMP_NONE:
+                break;
+
+            case TIMESTAMP_ABSOLUTE:
+                fprintf(fh, " (%zu.%zu) ",
+                    timestamp.tv_sec, timestamp.tv_usec);
+
+                break;
+        }
+
+        fprintf(fh, "%6s  %03X   [%d] ",
             ifname, frame.can_id, frame.can_dlc);
 
         for (i=0; i<frame.can_dlc; i++) {
@@ -86,18 +141,18 @@ int hexagram_main_can2dump(int argc, char **argv) {
         fprintf(fh, "\n");
     }
 
-    if (argc == 2) {
+    if (argn == 1) {
         hexagram_capture_destroy(capture);
-    } else if (argc >= 3) {
+    } else if (argn >= 2) {
         hexagram_capture_close(capture);
     }
 
     return 0;
 
 error_fopen:
-    if (argc == 2) {
+    if (argn == 1) {
         hexagram_capture_destroy(capture);
-    } else if (argc >= 3) {
+    } else if (argn >= 2) {
         hexagram_capture_close(capture);
     }