struct entry: Manual command line access? - objective-c

how does this code work: more precisely the line that passes the struct into the command line agc and argv ? what is it doing? Is there another way to do this?
#include <Foundation/Foundation.h>
int main (int argc, char * argv[]) {
struct entry dictionary[100] =
{ { "aardvark", "a burrowing African mammal" } ,
{ "abyss", "a bottomless pit' } ,
{ "acumen", "mentally sharp; keen"
{ "addle", "to become confused" } ,
{ "aerie", "a high nest" },
{ "affix","to append, attach" },
{ "agar"," a jelly made from seaweed" },
{ "ahoy"," a nautical call of greeting" },
{ "aigrette", "an ornamental cluster of feathers" } ,
{ "ajar", "partially opened" } } ;
int entries = 10;
int entryNumber;
int lookup (struct entry dictionary [], char search[],
int entries);
if ( argc != 2 ) {
NSLog (#"No word typed on the command line.");
return (1); }
entryNumber = lookup (dictionary, argv[1], entries);
if ( entryNumber != -1 )
NSLog (#"%s", dictionary[entryNumber].definition);
else
NSLog (#"Sorry, %s is not in my dictionary.", argv[1]);
return (0); }

Related

Port not bound SystemC (E112)

I am trying to implement a producer (master) speaking to a memory element (slave) through the memory controller (which implements the interface simple_mem_interface).
Note: Some functions details and include statements are not fully mentioned in the code attached.
Searching for bugs in the code.
Adding debugging tools to find the fault in Write Enable Port.
binding.cpp
int sc_main(int argc, char* argv[])
{
sc_signal<unsigned int> d_out,d_in,address_d;
sc_signal<bool> wen, ren, ack;
sc_clock ClkFast("ClkFast", 100, SC_NS);
sc_clock ClkSlow("ClkSlow", 50, SC_NS);
Memory_Controller Controller1 ("Controller");
d_out = Controller1.data_mem_read;
ren.write(Controller1.REN);
ack.write(Controller1.ack);
d_in.write(Controller1.data_write);
address_d.write(Controller1.address);
wen.write(Controller1.WEN);
producer P1("Producer");
P1.out(Controller1);
P1.Clk(ClkFast);
Memory_module MEM("Memory");
MEM.Wen(wen);
MEM.Ren(ren);
MEM.ack(ack);
MEM.Clock(ClkSlow);
MEM.data_in(d_in);
MEM.data_out(d_out);
MEM.address(address_d);
sc_start(5000, SC_NS);
return 0;
Memory_controller.h
#define MEM_SIZE 100
#include <interface_func.h>
class Memory_Controller : public sc_module, public simple_mem_if
{
public:
// Ports
sc_in <unsigned int> data_mem_read{ "Data_Read_from_Memory" };
sc_out<bool> REN { "Read_Enable" };
sc_out<bool> WEN { "Write_Enable" };
sc_out <bool> ack{ "ACK_Bool" };
sc_out<unsigned int> address{ "Memory_Address" }, data_write{
"Data_Written_to_Memory" };
// constructor
Memory_Controller(sc_module_name nm) : sc_module(nm)
{ // Creating a 2 dimentional array holding adresses and data
WEN.write(false);
REN.write(false);
ack.write(false);
}
~Memory_Controller() //destructor
{
}
bool Write(unsigned int address_i, unsigned int datum) // blocking write
{
WEN.write(true);
REN.write(false);
data_write.write(datum);
address.write(address_i);
if (ack == true)
return true;
else
return false;
}
bool Read(unsigned int address_i, unsigned int& datum_i) // blocking read
{
WEN.write(false);
REN.write(true);
datum_i=data_mem_read;
address.write(address_i);
if (ack == true)
return true;
else
return false;
}
void register_port(sc_port_base& port, const char* if_typename)
{
cout << "binding " << port.name() << " to "
<< "interface: " << if_typename << endl;
}
};
Memory.h
#define MEM_SIZE 100
#include "interface_func.h"
class Memory_module : public sc_module
{
public:
sc_in<bool> Wen,Ren;
sc_in <unsigned int> address, data_in ;
sc_in<bool> Clock;
sc_out <unsigned int> data_out;
sc_out <bool> ack;
bool fileinput = false;
ifstream myfile;
unsigned int item [MEM_SIZE];
Memory_module()
{
}
void Write() // blocking write
{
while (true)
{
wait();
if (Wen==true)
{
if (address >= MEM_SIZE || address < 0)
{
ack=false;
}
else
{
item[address]=data_in;
ack=true;
}
}
}
}
void Read() // blocking read
{
while (true)
{
wait();
if (Ren)
{
if (address >= MEM_SIZE || address < 0)
ack=false;
else
{
data_out.write(item[address]);
ack=true;
}
}
}
}
SC_CTOR(Memory_module)
{
SC_THREAD(Read);
sensitive << Clock.pos();
SC_THREAD(Write);
sensitive << Clock.pos();
}
};
interface_func.h
class simple_mem_if : virtual public sc_interface
{
public:
virtual bool Write(unsigned int addr, unsigned int data) = 0;
virtual bool Read(unsigned int addr, unsigned int& data) = 0;
};
After debugging the SystemC binder.cpp code, the following error arises:
(E112) get interface failed: port is not bound : port 'Controller.Write_Enable' (sc_out)
You cannot drive your unconnected ports in the Memory_Controller constructor. If you want to explicitly drive these ports during startup, move these calls to a start_of_simulation callback:
Memory_Controller(sc_module_name nm) : sc_module(nm)
{}
void start_of_simulation()
{
WEN.write(false);
REN.write(false);
ack.write(false);
}

How to change this app to disable input from command line?

This is the Original code:
#include <stdio.h>
#include <string.h>
#include <assert.h>
#if defined(_WIN32) && !defined(__CYGWIN__)
#include <windows.h>
#else
#include <sys/select.h>
#endif
#include <sphinxbase/err.h>
#include <sphinxbase/ad.h>
#include "pocketsphinx.h"
static const arg_t cont_args_def[] = {
POCKETSPHINX_OPTIONS,
/* Argument file. */
{"-argfile",
ARG_STRING,
NULL,
"Argument file giving extra arguments."},
{"-adcdev",
ARG_STRING,
NULL,
"Name of audio device to use for input."},
{"-infile",
ARG_STRING,
NULL,
"Audio file to transcribe."},
{"-inmic",
ARG_BOOLEAN,
"no",
"Transcribe audio from microphone."},
{"-time",
ARG_BOOLEAN,
"no",
"Print word times in file transcription."},
CMDLN_EMPTY_OPTION
};
static ps_decoder_t *ps;
static cmd_ln_t *config;
static FILE *rawfd;
static void
print_word_times()
{
int frame_rate = cmd_ln_int32_r(config, "-frate");
ps_seg_t *iter = ps_seg_iter(ps);
while (iter != NULL) {
int32 sf, ef, pprob;
float conf;
ps_seg_frames(iter, &sf, &ef);
pprob = ps_seg_prob(iter, NULL, NULL, NULL);
conf = logmath_exp(ps_get_logmath(ps), pprob);
printf("%s %.3f %.3f %f\n", ps_seg_word(iter), ((float)sf / frame_rate),
((float) ef / frame_rate), conf);
iter = ps_seg_next(iter);
}
}
static int
check_wav_header(char *header, int expected_sr)
{
int sr;
if (header[34] != 0x10) {
E_ERROR("Input audio file has [%d] bits per sample instead of 16\n", header[34]);
return 0;
}
if (header[20] != 0x1) {
E_ERROR("Input audio file has compression [%d] and not required PCM\n", header[20]);
return 0;
}
if (header[22] != 0x1) {
E_ERROR("Input audio file has [%d] channels, expected single channel mono\n", header[22]);
return 0;
}
sr = ((header[24] & 0xFF) | ((header[25] & 0xFF) << 8) | ((header[26] & 0xFF) << 16) | ((header[27] & 0xFF) << 24));
if (sr != expected_sr) {
E_ERROR("Input audio file has sample rate [%d], but decoder expects [%d]\n", sr, expected_sr);
return 0;
}
return 1;
}
/*
* Continuous recognition from a file
*/
static void
recognize_from_file()
{
int16 adbuf[2048];
const char *fname;
const char *hyp;
int32 k;
uint8 utt_started, in_speech;
int32 print_times = cmd_ln_boolean_r(config, "-time");
fname = cmd_ln_str_r(config, "-infile");
if ((rawfd = fopen(fname, "rb")) == NULL) {
E_FATAL_SYSTEM("Failed to open file '%s' for reading",
fname);
}
if (strlen(fname) > 4 && strcmp(fname + strlen(fname) - 4, ".wav") == 0) {
char waveheader[44];
fread(waveheader, 1, 44, rawfd);
if (!check_wav_header(waveheader, (int)cmd_ln_float32_r(config, "-samprate")))
E_FATAL("Failed to process file '%s' due to format mismatch.\n", fname);
}
if (strlen(fname) > 4 && strcmp(fname + strlen(fname) - 4, ".mp3") == 0) {
E_FATAL("Can not decode mp3 files, convert input file to WAV 16kHz 16-bit mono before decoding.\n");
}
ps_start_utt(ps);
utt_started = FALSE;
while ((k = fread(adbuf, sizeof(int16), 2048, rawfd)) > 0) {
ps_process_raw(ps, adbuf, k, FALSE, FALSE);
in_speech = ps_get_in_speech(ps);
if (in_speech && !utt_started) {
utt_started = TRUE;
}
if (!in_speech && utt_started) {
ps_end_utt(ps);
hyp = ps_get_hyp(ps, NULL);
if (hyp != NULL)
printf("%s\n", hyp);
if (print_times)
print_word_times();
fflush(stdout);
ps_start_utt(ps);
utt_started = FALSE;
}
}
ps_end_utt(ps);
if (utt_started) {
hyp = ps_get_hyp(ps, NULL);
if (hyp != NULL) {
printf("%s\n", hyp);
if (print_times) {
print_word_times();
}
}
}
fclose(rawfd);
}
/* Sleep for specified msec */
static void
sleep_msec(int32 ms)
{
#if (defined(_WIN32) && !defined(GNUWINCE)) || defined(_WIN32_WCE)
Sleep(ms);
#else
/* ------------------- Unix ------------------ */
struct timeval tmo;
tmo.tv_sec = 0;
tmo.tv_usec = ms * 1000;
select(0, NULL, NULL, NULL, &tmo);
#endif
}
/*
* Main utterance processing loop:
* for (;;) {
* start utterance and wait for speech to process
* decoding till end-of-utterance silence will be detected
* print utterance result;
* }
*/
static void
recognize_from_microphone()
{
ad_rec_t *ad;
int16 adbuf[2048];
uint8 utt_started, in_speech;
int32 k;
char const *hyp;
if ((ad = ad_open_dev(cmd_ln_str_r(config, "-adcdev"),
(int) cmd_ln_float32_r(config,
"-samprate"))) == NULL)
E_FATAL("Failed to open audio device\n");
if (ad_start_rec(ad) < 0)
E_FATAL("Failed to start recording\n");
if (ps_start_utt(ps) < 0)
E_FATAL("Failed to start utterance\n");
utt_started = FALSE;
E_INFO("Ready....\n");
for (;;) {
if ((k = ad_read(ad, adbuf, 2048)) < 0)
E_FATAL("Failed to read audio\n");
ps_process_raw(ps, adbuf, k, FALSE, FALSE);
in_speech = ps_get_in_speech(ps);
if (in_speech && !utt_started) {
utt_started = TRUE;
E_INFO("Listening...\n");
}
if (!in_speech && utt_started) {
/* speech -> silence transition, time to start new utterance */
ps_end_utt(ps);
hyp = ps_get_hyp(ps, NULL );
if (hyp != NULL) {
printf("%s\n", hyp);
fflush(stdout);
}
if (ps_start_utt(ps) < 0)
E_FATAL("Failed to start utterance\n");
utt_started = FALSE;
E_INFO("Ready....\n");
}
sleep_msec(100);
}
ad_close(ad);
}
int
main(int argc, char *argv[])
{
char const *cfg;
config = cmd_ln_parse_r(NULL, cont_args_def, argc, argv, TRUE);
/* Handle argument file as -argfile. */
if (config && (cfg = cmd_ln_str_r(config, "-argfile")) != NULL) {
config = cmd_ln_parse_file_r(config, cont_args_def, cfg, FALSE);
}
if (config == NULL || (cmd_ln_str_r(config, "-infile") == NULL && cmd_ln_boolean_r(config, "-inmic") == FALSE)) {
E_INFO("Specify '-infile <file.wav>' to recognize from file or '-inmic yes' to recognize from microphone.\n");
cmd_ln_free_r(config);
return 1;
}
ps_default_search_args(config);
ps = ps_init(config);
if (ps == NULL) {
cmd_ln_free_r(config);
return 1;
}
E_INFO("%s COMPILED ON: %s, AT: %s\n\n", argv[0], __DATE__, __TIME__);
if (cmd_ln_str_r(config, "-infile") != NULL) {
recognize_from_file();
} else if (cmd_ln_boolean_r(config, "-inmic")) {
recognize_from_microphone();
}
ps_free(ps);
cmd_ln_free_r(config);
return 0;
}
#if defined(_WIN32_WCE)
#pragma comment(linker,"/entry:mainWCRTStartup")
#include <windows.h>
//Windows Mobile has the Unicode main only
int
wmain(int32 argc, wchar_t * wargv[])
{
char **argv;
size_t wlen;
size_t len;
int i;
argv = malloc(argc * sizeof(char *));
for (i = 0; i < argc; i++) {
wlen = lstrlenW(wargv[i]);
len = wcstombs(NULL, wargv[i], wlen);
argv[i] = malloc(len + 1);
wcstombs(argv[i], wargv[i], wlen);
}
//assuming ASCII parameters
return main(argc, argv);
}
#endif
I can compile it by this command:
g++ -o output continuous.cpp -DMODELDIR=\"`pkg-config --variable=modeldir pocketsphinx`\" `pkg-config --cflags --libs pocketsphinx sphinxbase`
And run it by this command : output -inmic yes .
But I like to convert the code as it has no need to get inmic yes and it automatically starts the program from microphone. But I got segmentation fault(core dumped) error when I changed these parts:
static const arg_t cont_args_def= {"-inmic",
ARG_BOOLEAN,
"no",
"Transcribe audio from microphone."};
int main(int argc, char *argv[])
{
config = cmd_ln_parse_r(NULL, cont_args_def, argc, argv, TRUE);
if (cmd_ln_boolean_r(config, "-inmic")) {
recognize_from_microphone();
}
// recognize_from_microphone();
ps_free(ps);
cmd_ln_free_r(config);
return 0;
}
I searched a lot and red the documentation but couldn't understand what's the problem?
Change the last argument passed to cmd_ln_parse_r from TRUE to FALSE.
It has something to do with strict checking.
I figured this out by reading the source code for cmd_ln.c in the sphinxbase code.
I also changed the boolean value for -inmic in cont_args_def from "no" to "yes".

calling Objective C and C from Swift passing callback function

I am trying to call the HappyTime onvif library from Swift.
I have the library linked in to my project and I am able to call some simple functions, but I am having trouble getting the syntax right in my call which passes my callback function.
Here is the Swift code:
func discoverCameras()
{
HappyInterface.sharedInstance().startProb()
//this line gives syntax error
HappyInterface.sharedInstance().setProbeCB(cameraDiscovered)
}
func cameraDiscovered(cameraFound:UnsafeMutablePointer<DEVICE_BINFO>)
{
table.reloadData()
}
my setProbeCB call gives this error:
Cannot convert value of type '(UnsafeMutablePointer) -> ()' to expected argument type 'UnsafeMutablePointer' (aka 'UnsafeMutablePointer, UnsafeMutablePointer<()>) -> ()>>')
Here is the Obj C implementation:
- (void) setProbeCB:(onvif_probe_cb *)cb {
set_probe_cb(*cb, 0);
}
This is the Obj C header:
- (void) setProbeCB:(onvif_probe_cb *)cb;
This is the C header:
#ifndef __H_ONVIF_PROBE_H__
#define __H_ONVIF_PROBE_H__
#include "onvif.h"
typedef void (* onvif_probe_cb)(DEVICE_BINFO * p_res, void * pdata);
#ifdef __cplusplus
extern "C" {
#endif
ONVIF_API void set_probe_cb(onvif_probe_cb cb, void * pdata);
ONVIF_API void set_probe_interval(int interval);
ONVIF_API int start_probe(int interval);
ONVIF_API void stop_probe();
ONVIF_API void send_probe_req();
#ifdef __cplusplus
}
#endif
#endif // __H_ONVIF_PROBE_H__
This is the C code:
/***************************************************************************************/
#define MAX_PROBE_FD 8
/***************************************************************************************/
onvif_probe_cb g_probe_cb = 0;
void * g_probe_cb_data = 0;
pthread_t g_probe_thread = 0;
int g_probe_fd[MAX_PROBE_FD];
int g_probe_interval = 30;
BOOL g_probe_running = FALSE;
/***************************************************************************************/
int onvif_probe_init(unsigned int ip)
{
int opt = 1;
SOCKET fd;
struct sockaddr_in addr;
struct ip_mreq mcast;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if(fd < 0)
{
log_print(LOG_ERR, "socket SOCK_DGRAM error!\n");
return -1;
}
addr.sin_family = AF_INET;
addr.sin_port = htons(3702);
addr.sin_addr.s_addr = ip;
if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
{
// if port 3702 already occupied, only receive unicast message
addr.sin_port = 0;
if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
{
closesocket(fd);
log_print(LOG_ERR, "bind error! %s\n", sys_os_get_socket_error());
return -1;
}
}
/* reuse socket addr */
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char*)&opt, sizeof(opt)))
{
log_print(LOG_WARN, "setsockopt SO_REUSEADDR error!\n");
}
memset(&mcast, 0, sizeof(mcast));
mcast.imr_multiaddr.s_addr = inet_addr("239.255.255.250");
mcast.imr_interface.s_addr = ip;
if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&mcast, sizeof(mcast)) < 0)
{
#if __WIN32_OS__
if(setsockopt(fd, IPPROTO_IP, 5, (char*)&mcast, sizeof(mcast)) < 0)
#endif
{
closesocket(fd);
log_print(LOG_ERR, "setsockopt IP_ADD_MEMBERSHIP error! %s\n", sys_os_get_socket_error());
return -1;
}
}
return fd;
}
char probe_req1[] =
"<?xml version=\"1.0\" encoding=\"utf-8\"?>"
"<Envelope xmlns:tds=\"http://www.onvif.org/ver10/device/wsdl\" xmlns=\"http://www.w3.org/2003/05/soap-envelope\">"
"<Header>"
"<wsa:MessageID xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">uuid:%s</wsa:MessageID>"
"<wsa:To xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">urn:schemas-xmlsoap-org:ws:2005:04:discovery</wsa:To>"
"<wsa:Action xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">http://schemas.xmlsoap.org/ws/2005/04/discovery/Probe</wsa:Action>"
"</Header>"
"<Body>"
"<Probe xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns=\"http://schemas.xmlsoap.org/ws/2005/04/discovery\">"
"<Types>tds:Device</Types>"
"<Scopes />"
"</Probe>"
"</Body>"
"</Envelope>";
char probe_req2[] =
"<?xml version=\"1.0\" encoding=\"utf-8\"?>"
"<Envelope xmlns:dn=\"http://www.onvif.org/ver10/network/wsdl\" xmlns=\"http://www.w3.org/2003/05/soap-envelope\">"
"<Header>"
"<wsa:MessageID xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">uuid:%s</wsa:MessageID>"
"<wsa:To xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">urn:schemas-xmlsoap-org:ws:2005:04:discovery</wsa:To>"
"<wsa:Action xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">http://schemas.xmlsoap.org/ws/2005/04/discovery/Probe</wsa:Action>"
"</Header>"
"<Body>"
"<Probe xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns=\"http://schemas.xmlsoap.org/ws/2005/04/discovery\">"
"<Types>dn:NetworkVideoTransmitter</Types>"
"<Scopes />"
"</Probe>"
"</Body>"
"</Envelope>";
int onvif_probe_req_tx(int fd)
{
int len;
int rlen;
char * p_bufs = NULL;
struct sockaddr_in addr;
int buflen = 10*1024;
p_bufs = (char *)malloc(buflen);
if (NULL == p_bufs)
{
return -1;
}
memset(p_bufs, 0, buflen);
sprintf(p_bufs, probe_req1, onvif_uuid_create());
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = inet_addr("239.255.255.250");
addr.sin_port = htons(3702);
len = strlen(p_bufs);
rlen = sendto(fd, p_bufs, len, 0, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
if (rlen != len)
{
log_print(LOG_ERR, "onvif_probe_req_tx::rlen = %d,slen = %d\r\n", rlen, len);
}
usleep(1000);
memset(p_bufs, 0, buflen);
sprintf(p_bufs, probe_req2, onvif_uuid_create());
len = strlen(p_bufs);
rlen = sendto(fd, p_bufs, len, 0, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
if (rlen != len)
{
log_print(LOG_ERR, "onvif_probe_req_tx::rlen = %d,slen = %d\r\n", rlen, len);
}
free(p_bufs);
return rlen;
}
BOOL onvif_parse_device_binfo(XMLN * p_node, DEVICE_BINFO * p_res)
{
XMLN * p_EndpointReference;
XMLN * p_Types;
XMLN * p_XAddrs;
p_EndpointReference = xml_node_soap_get(p_node, "EndpointReference");
if (p_EndpointReference)
{
XMLN * p_Address = xml_node_soap_get(p_EndpointReference, "Address");
if (p_Address && p_Address->data)
{
strncpy(p_res->EndpointReference, p_Address->data, sizeof(p_res->EndpointReference)-1);
}
}
p_Types = xml_node_soap_get(p_node, "Types");
if (p_Types && p_Types->data)
{
p_res->type = parse_DeviceType(p_Types->data);
}
p_XAddrs = xml_node_soap_get(p_node, "XAddrs");
if (p_XAddrs && p_XAddrs->data)
{
parse_XAddr(p_XAddrs->data, &p_res->XAddr);
if (p_res->XAddr.host[0] == '\0' || p_res->XAddr.port == 0)
{
return FALSE;
}
}
else
{
return FALSE;
}
return TRUE;
}
BOOL onvif_probe_res(XMLN * p_node, DEVICE_BINFO * p_res)
{
XMLN * p_body = xml_node_soap_get(p_node, "Body");
if (p_body)
{
XMLN * p_ProbeMatches = xml_node_soap_get(p_body, "ProbeMatches");
if (p_ProbeMatches)
{
XMLN * p_ProbeMatch = xml_node_soap_get(p_ProbeMatches, "ProbeMatch");
while (p_ProbeMatch && soap_strcmp(p_ProbeMatch->name, "ProbeMatch") == 0)
{
if (onvif_parse_device_binfo(p_ProbeMatch, p_res))
{
if (g_probe_cb)
{
g_probe_cb(p_res, g_probe_cb_data);
}
}
p_ProbeMatch = p_ProbeMatch->next;
}
}
else
{
XMLN * p_Hello = xml_node_soap_get(p_body, "Hello");
if (p_Hello)
{
if (onvif_parse_device_binfo(p_Hello, p_res))
{
if (g_probe_cb)
{
g_probe_cb(p_res, g_probe_cb_data);
}
}
}
}
}
return TRUE;
}
int onvif_probe_net_rx()
{
int i;
int ret;
int maxfd = 0;
int fd = 0;
char rbuf[10*1024];
fd_set fdread;
struct timeval tv = {1, 0};
FD_ZERO(&fdread);
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
FD_SET(g_probe_fd[i], &fdread);
if (g_probe_fd[i] > maxfd)
{
maxfd = g_probe_fd[i];
}
}
}
ret = select(maxfd+1, &fdread, NULL, NULL, &tv);
if (ret == 0) // Time expired
{
return 0;
}
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0 && FD_ISSET(g_probe_fd[i], &fdread))
{
int rlen;
int addr_len;
struct sockaddr_in addr;
unsigned int src_ip;
unsigned int src_port;
XMLN * p_node;
fd = g_probe_fd[i];
addr_len = sizeof(struct sockaddr_in);
rlen = recvfrom(fd, rbuf, sizeof(rbuf), 0, (struct sockaddr *)&addr, (socklen_t*)&addr_len);
if (rlen <= 0)
{
log_print(LOG_ERR, "onvif_probe_net_rx::rlen = %d, fd = %d\r\n", rlen, fd);
continue;
}
src_ip = addr.sin_addr.s_addr;
src_port = addr.sin_port;
p_node = xxx_hxml_parse(rbuf, rlen);
if (p_node == NULL)
{
log_print(LOG_ERR, "onvif_probe_net_rx::hxml parse err!!!\r\n");
}
else
{
DEVICE_BINFO res;
memset(&res, 0, sizeof(DEVICE_BINFO));
onvif_probe_res(p_node, &res);
}
xml_node_del(p_node);
}
}
return 1;
}
void * onvif_probe_thread(void * argv)
{
int count = 0;
int i = 0;
int j = 0;
for (; i < get_if_nums() && j < MAX_PROBE_FD; i++, j++)
{
unsigned int ip = get_if_ip(i);
if (ip != 0 && ip != inet_addr("127.0.0.1"))
{
g_probe_fd[j] = onvif_probe_init(ip);
}
}
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
onvif_probe_req_tx(g_probe_fd[i]);
}
}
while (g_probe_running)
{
if (onvif_probe_net_rx() == 0)
{
count++;
}
if (count >= g_probe_interval)
{
count = 0;
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
onvif_probe_req_tx(g_probe_fd[i]);
}
}
}
usleep(1000);
}
g_probe_thread = 0;
return NULL;
}
ONVIF_API void set_probe_cb(onvif_probe_cb cb, void * pdata)
{
g_probe_cb = cb;
g_probe_cb_data = pdata;
}
ONVIF_API void send_probe_req()
{
int i;
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
onvif_probe_req_tx(g_probe_fd[i]);
}
}
}
ONVIF_API void set_probe_interval(int interval)
{
g_probe_interval = interval;
if (g_probe_interval < 10)
{
g_probe_interval = 30;
}
}
ONVIF_API int start_probe(int interval)
{
g_probe_running = TRUE;
set_probe_interval(interval);
g_probe_thread = sys_os_create_thread((void *)onvif_probe_thread, NULL);
if (g_probe_thread)
{
return 0;
}
return -1;
}
ONVIF_API void stop_probe()
{
int i;
g_probe_running = FALSE;
while (g_probe_thread)
{
usleep(1000);
}
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
closesocket(g_probe_fd[i]);
g_probe_fd[i] = 0;
}
}
}
Here is what the DEVICE_BINFO struct looks like:
typedef struct
{
int type; // device type
char EndpointReference[100];
onvif_XAddr XAddr; // xaddr, include port host, url
} DEVICE_BINFO;
One thing that should be fixed is a mismatch in the number of arguments to the callback. Swift calls the Objective-C setProbeCB() method, giving it a pointer to the cameraDiscovered() function, which takes a single argument. Then setProbeCB() gives the function pointer to the C set_probe_cb() function, which expects a pointer to a function that takes two arguments.
Another observation is that setProbeCB() could just take onvif_probe_cb instead of onvif_probe_cb* and then call C code simply as set_probe_cb(cb, 0). However, I don't think it makes much difference.
Also, I think the question could have been distilled to a smaller size.
The following is a simplified example based on your original code. It shows how to implement a callback in Swift and have C code call it, but the real fun starts when passing data via callback parameters and return values. It gets very tricky very fast, and that's why the example doesn't show how to deal with DEVICE_BINFO in Swift code. It's a topic in its own right.
The clue to using (Objective-)C functions and types in Swift is figuring out how they are imported into Swift. For example, to find out how onvif_probe_cb is imported, type it on a line in the Swift code, place the cursor in it, and Quick Help will show you this:
Declaration: typealias onvif_probe_cb = (UnsafeMutablePointer<DEVICE_BINFO>, UnsafeMutablePointer<Void>) -> Void
Declared in: clib.h
That tells us the parameter and return types to use in our Swift implementation of the callback.
The example is by no means production quality: there are all kinds of things that can go haywire in terms of memory management etc. Please see the code comments for additional info.
First, here is the C code header (clib.h):
#ifndef clib_h
#define clib_h
#include <stdio.h>
typedef struct {
char hostname[50];
int32_t port;
char url[200];
} onvif_XAddr;
typedef struct
{
int type; // device type
char EndpointReference[100];
onvif_XAddr XAddr; // xaddr, include port host, url
} DEVICE_BINFO;
/**
* This is the typedef of the function pointer to be used for our callback.
* The function takes a pointer to DEVICE_BINFO and a pointer to some arbitrary
* data meaningful to the code that provides the callback implementation. It will
* be NULL in this example.
*/
typedef void (* onvif_probe_cb)(DEVICE_BINFO * p_res, void * pdata);
/**
* A function to set the callback.
*/
void set_probe_cb(onvif_probe_cb cb, void * pdata);
/**
* This is a function that calls the callback.
*/
void find_device();
#endif /* clib_h */
Here is the rest of our C source (clib.c):
#include "clib.h"
#include <string.h>
onvif_probe_cb gCB = 0; // global variable to store the callback pointer
void * gUserData = 0; // global variable to store pointer to user data
DEVICE_BINFO gDeviceInfo; // global variable to store device info struct
void find_device() {
// Set up gDeviceInfo
gDeviceInfo.XAddr.port = 1234;
strcpy( gDeviceInfo.XAddr.hostname, "myhost");
strcpy( gDeviceInfo.XAddr.url, "http://junk.com");
gDeviceInfo.type = 777;
// ... and, if a callback is available, call it with the device info
if (gCB) gCB(&gDeviceInfo, gUserData);
else puts("No callback available");
}
void set_probe_cb(onvif_probe_cb cb, void * pdata) {
gCB = cb;
gUserData = pdata;
}
Here is the Objective-C wrapper header (oclib.h):
#ifndef oclib_h
#define oclib_h
#import "clib.h"
#import <Foundation/Foundation.h>
/**
* Interface of an Objective-C wrapper around C code in clib.*. We could have
* gone straight to C from Swift, but I'm trying to keep the example close to the
* code in the question. Also, this extra Objective C layer could be helpful in
* translating data structures, such as DEVICE_BINFO, between C and Swift, since
* Objective-C plays much nicer with C data types. This is no surprise: any C code
* is valid Objective-C (Objective-C is a strict superset of C).
*/
#interface MyWrapper : NSObject
-(id)init;
// Please note: this one takes a single argument, while the C function it wraps
// takes 2; see the implementation.
-(void) setProbeCB:(onvif_probe_cb) cb;
-(void) findDevice;
#end
#endif /* oclib_h */
And the wrapper implementation (oclib.m):
#import "oclib.h"
/**
* Implementation of our Objective-C wrapper.
*/
#implementation MyWrapper
-(id)init { return self; }
-(void) setProbeCB:(onvif_probe_cb) cb {
// We don't want anything other than device info to be passed back and
// forth via the callback, so this wrapper function takes a single argument
// and passes 0 as the 2nd argument to the wrapped C function.
set_probe_cb(cb, 0);
}
-(void) findDevice {
find_device();
}
#end
Finally, here is the Swift code that implements the callback (main.swift):
var w : MyWrapper = MyWrapper()
/**
* This is the callback implementation in Swift. We don't use the 2nd argument, userData, but it still
* has to be present to satisfy the way the callback function pointer is specified in C code.
*/
func cameraDiscovered( info : UnsafeMutablePointer<DEVICE_BINFO>, userData : UnsafeMutablePointer<Void>) {
print("Called the Swift callback!")
let devInfo : DEVICE_BINFO = info.memory;
print( "The device type is \(devInfo.type)")
print( "The device port is \(devInfo.XAddr.port)")
}
// Provide the callback to C code via Objective-C
w.setProbeCB(cameraDiscovered)
// ... and call a function that will cause the C code to invoke the callback.
w.findDevice()
The bridging header just has #import oclib.h, thus exposing the contents of both C and Objective-C headers to Swift.
The expected output:
Called the Swift callback!
The device type is 777
The device port is 1234

how to find the first and follow values of grammar

i have the following grammar and i would like to create the First & follow table. if i have a case that the first of non terminal is epsilon should i take also all the terminals that came after this non terminal from is rule?
S-> ABC
A->Aa/aB
B->Bb/epsilon
C->Cc/epsilon
and my question is:
in the first of C i need to get First(C) = {epsilon,c) and First(B) = {epsilon,b)?
i got the following results but still i think i have problems:
|first|follow
S |a |$
A |a |a
B |eps,b|b,a,$
C |eps,c|$
Finding the FIRST and Follow of a Grammar written in txt FILE:
#include<stdio.h>
#include<string.h>
#define size 10
int i,j,l,m,n=0,o,p,nv,z=0,x=0;
char str[size],temp,temp2[size],temp3[20],*ptr;
struct prod
{
char left_of_non_term[size],right_of_nonTerm[size][size],first[size],fol[size];
int n;
}pro[size];
int main()
{
FILE *f;
for(i=0;i<size;i++)
pro[i].n=0;
f=fopen("lab6.txt","r");
while(!feof(f))
{
fscanf(f,"%s",pro[n].left_of_non_term);
if(n>0)
{
if( strcmp(pro[n].left_of_non_term,pro[n-1].left_of_non_term) == 0 )
{
pro[n].left_of_non_term[0]='\0';
fscanf(f,"%s",pro[n-1].right_of_nonTerm[pro[n-1].n]);
pro[n-1].n++;
continue;
}
}
fscanf(f,"%s",pro[n].right_of_nonTerm[pro[n].n]);
pro[n].n++;
n++;
}
printf("\nGiven Grammar");
printf("\n-------------\n");
for(i=0;i<n;i++)
for(j=0;j<pro[i].n;j++)
printf("%s = %s\n",pro[i].left_of_non_term,pro[i].right_of_nonTerm[j]);
pro[0].first[0]='#';
for(i=0;i<n;i++)
{
for(j=0;j<pro[i].n;j++)
{
if( pro[i].right_of_nonTerm[j][0]<65 || pro[i].right_of_nonTerm[j][0]>90 )
{
pro[i].first[strlen(pro[i].first)]=pro[i].right_of_nonTerm[j][0];
}
else if( pro[i].right_of_nonTerm[j][0]>=65 && pro[i].right_of_nonTerm[j][0]<=90 )
{
temp=pro[i].right_of_nonTerm[j][0];
if(temp=='S')
pro[i].first[strlen(pro[i].first)]='#';
findter();
}
}
}
printf("-------------");
printf("\n\nFIRST\n");
for(i=0;i<n;i++)
{
printf("\n%s -> { ",pro[i].left_of_non_term);
for(j=0;j<strlen(pro[i].first);j++)
{
for(l=j-1;l>=0;l--)
if(pro[i].first[l]==pro[i].first[j])
break;
if(l==-1)
printf("%c ",pro[i].first[j]);
}
printf("}");
}
for(i=0;i<n;i++)
temp2[i]=pro[i].left_of_non_term[0];
pro[0].fol[0]='$';
for(i=0;i<n;i++)
{
for(l=0;l<n;l++)
{
for(j=0;j<pro[i].n;j++)
{
ptr=strchr(pro[l].right_of_nonTerm[j],temp2[i]);
if( ptr )
{
p=ptr-pro[l].right_of_nonTerm[j];
if(pro[l].right_of_nonTerm[j][p+1]>=65 && pro[l].right_of_nonTerm[j][p+1]<=90)
{
for(o=0;o<n;o++)
if(pro[o].left_of_non_term[0]==pro[l].right_of_nonTerm[j][p+1])
strcat(pro[i].fol,pro[o].first);
}
else if(pro[l].right_of_nonTerm[j][p+1]=='\0')
{
temp=pro[l].left_of_non_term[0];
if(pro[l].right_of_nonTerm[j][p]==temp)
continue;
if(temp=='S')
strcat(pro[i].fol,"$");
findfol();
}
else
pro[i].fol[strlen(pro[i].fol)]=pro[l].right_of_nonTerm[j][p+1];
}
}
}
}
printf("\n\n\n");
for(i=0;i<n;i++)
{
printf("\nFOLLOW (%s) -> { ",pro[i].left_of_non_term);
for(j=0;j<strlen(pro[i].fol);j++)
{
for(l=j-1;l>=0;l--)
if(pro[i].fol[l]==pro[i].fol[j])
break;
if(l==-1)
printf("%c",pro[i].fol[j]);
}
printf(" }");
}
printf("\n");
//getch();
}
void findter()
{
int k,t;
for(k=0;k<n;k++)
{
if(temp==pro[k].left_of_non_term[0])
{
for(t=0;t<pro[k].n;t++)
{
if( pro[k].right_of_nonTerm[t][0]<65 || pro[k].right_of_nonTerm[t][0]>90 )
pro[i].first[strlen(pro[i].first)]=pro[k].right_of_nonTerm[t][0];
else if( pro[k].right_of_nonTerm[t][0]>=65 && pro[k].right_of_nonTerm[t][0]<=90 )
{
temp=pro[k].right_of_nonTerm[t][0];
if(temp=='S')
pro[i].first[strlen(pro[i].first)]='#';
findter();
}
}
break;
}
}
}
void findfol()
{
int k,t,p1,o1,chk;
char *ptr1;
for(k=0;k<n;k++)
{
chk=0;
for(t=0;t<pro[k].n;t++)
{
ptr1=strchr(pro[k].right_of_nonTerm[t],temp);
if( ptr1 )
{
p1=ptr1-pro[k].right_of_nonTerm[t];
if(pro[k].right_of_nonTerm[t][p1+1]>=65 && pro[k].right_of_nonTerm[t][p1+1]<=90)
{
for(o1=0;o1<n;o1++)
if(pro[o1].left_of_non_term[0]==pro[k].right_of_nonTerm[t][p1+1])
{
strcat(pro[i].fol,pro[o1].first);
chk++;
}
}
else if(pro[k].right_of_nonTerm[t][p1+1]=='\0')
{
temp=pro[k].left_of_non_term[0];
if(pro[l].right_of_nonTerm[j][p]==temp)
continue;
if(temp=='S')
strcat(pro[i].fol,"$");
findfol();
chk++;
}
else
{
pro[i].fol[strlen(pro[i].fol)]=pro[k].right_of_nonTerm[t]
[p1+1];
chk++;
}
}
}
if(chk>0)
break;
}
}
Also Make a text File named it lab6.txt . and put grammers like below
S ABCDE
A a|0
B b|0
C c
D d|0
E e|0
Here space after NonTerminal Indicates the -> this sign and 0 indicates epsilon.

if statement obj-c zero input

here is code.
int main(int argc, const char * argv[])
{
#autoreleasepool {
int x,y;
//BOOL divsibleYESOrNo;
NSLog(#"enter two number for test it\n");
scanf("%i %i",&x,&y);
if ( x%y ==0 ) {
NSLog(#"YES,it can be");
}
else if (x%y !=0) {
NSLog(#"no there cant.");
}
else
NSLog(#"zero is not allow");
}
return 0;
}
this code can not detect if the user input two zero.
how can I modify this code that can detect the input values are zero?
Thanks
Anything % 0 is undefined, so you'll need to add a check for y == 0 before your other if statements. It has to be the first if statement in order to make sure it gets evaluated; otherwise one of your other statements will catch it erroneously first.
if ( y == 0 ) {
NSLog(#"zero is not allowed.");
}
else if ( x%y == 0 ) {
NSLog(#"YES,it can be");
}
else {
NSLog(#"no there cant.");
}