small fixed to readme and arg-parse

Signed-off-by: Kamel Fakih <kamelfakihh@gmail.com>

examples/acf-can/README.md

@@ -3,7 +3,7 @@
 The two applications available in this folder are acf-can-listener and acf-can-talker. These applications can be used along with Linux CAN utilities. On Ubuntu/Debian Linux distributions, these utilities can be installed using the package manager `apt install can-utils`
 
 ## acf-can-talker
-_acf-can-talker_ receives frames on a (virtual) CAN interface and send out the corresponding IEEE 1722 ACF messages. This application also supports a UDP encapsulation for the IEEE 1722 messages. The parameters for its usage are as follows:
+_acf-can-talker_ receives frames on a (virtual) CAN interface and sends out the corresponding IEEE 1722 ACF messages. This application also supports UDP encapsulation for the IEEE 1722 messages. The parameters for its usage are as follows:
 
 ```
 Usage: acf-can-talker [OPTION...]
@@ -46,8 +46,9 @@ CAN bus over Ethernet using Open1722.
 
 ## Quickstart Tutorial: Tunneling CAN over IEEE 1722 using Linux CAN utilities
 Here is an example of how CAN frames can be tunneled over an Ethernet link using _acf-can-talker_ and _acf-can-listener_.
-We use two virtual CAN interfaces, _vcan0_ and _vcan1_, here which can be setup using following commands:
+We use two virtual CAN interfaces, _vcan0_ and _vcan1_, which can be setup using following commands:
 ```
+$ modprobe vcan
 $ ip link add dev vcan0 type vcan   # Execute these commands also for vcan1
 $ ip link set dev vcan0 up
 ```
@@ -71,19 +72,17 @@ $ ./acf-can-talker --dst-addr aa:bb:cc:dd:ee:ff -i eth0 --canif vcan0
 ```
 
 ### Use Listener Application for receiving
-On Terminal 3, receive the IEEE 1722 traffic using _acf-can-listener_ for putting the CAN frame out on vcan1.
+On Terminal 3, receive the IEEE 1722 traffic using _acf-can-listener_ and put the CAN frame out on vcan1.
 
-If the talke uses UDP encapsulation:
+If the talker uses UDP encapsulation:
 ```
-$ acf-can-listener -u -p 17220 --canif vcan1
+$ ./acf-can-listener -u -p 17220 --canif vcan1
 ```
 
 Alternatively, if Ethernet is directly used:
 ```
 $ ./acf-can-listener --dst-addr aa:bb:cc:dd:ee:ff -i eth0 --canif vcan0
 ```
 
-You can now compare CAN traffic seen on _vcan0 and vcan1_, if the tunneling has worked.
+You can now compare CAN traffic seen on _vcan0 and vcan1_ to check if the tunneling works.
 Note that the tunneling works in these examples only in one direction (_vcan0_ -> _vcan1_).
-
-

examples/acf-can/acf-can-listener.c

@@ -66,8 +66,8 @@ static char doc[] =
         \vEXAMPLES\n\
         acf-can-listener -i eth0 -d aa:bb:cc:dd:ee:ff --canif can1\n\
         \t(tunnel Open1722 CAN messages received from eth0 to can1)\n\
-        acf-can-listener --canif can1 -u -p 1722\n\
-        \t(tunnel Open1722 CAN messages received over UDP from port 1722 to can1)";
+        acf-can-listener --canif can1 -u -p 17220\n\
+        \t(tunnel Open1722 CAN messages received over UDP from port 17220 to can1)";
 
 static struct argp_option options[] = {
     {"udp", 'u', 0, 0, "Use UDP" },
@@ -112,7 +112,7 @@ static error_t parser(int key, char *arg, struct argp_state *state)
     return 0;
 }
 
-static struct argp argp = { options, parser };
+static struct argp argp = { options, parser, NULL, doc};
 
 static int is_valid_acf_packet(uint8_t* acf_pdu)
 {

examples/acf-can/acf-can-talker.c

@@ -137,7 +137,7 @@ static error_t parser(int key, char *arg, struct argp_state *state)
     return 0;
 }
 
-static struct argp argp = { options, parser};
+static struct argp argp = { options, parser, NULL, doc};
 
 static int init_cf_pdu(uint8_t* pdu)
 {
@@ -223,7 +223,7 @@ int main(int argc, char *argv[])
     uint16_t pdu_length, cf_length;
     frame_t can_frame;
 
-    argp_parse(&argp, argc, argv, 0, NULL, NULL);
+    argp_parse(&argp, argc, argv, doc, NULL, NULL);
 
     // Create an appropriate talker socket: UDP or Ethernet raw
     // Setup the socket for sending to the destination