[C] Output mancante con uso di printf()

[AMRITA1979]

Ciao,
sto scrivendo un client in C, dato che vorrei vedere se sono riuscita a fare bene tutte le connessioni con il socket, volevo fare un debug.
Il problema è che metto printf() dovunque ma sullo schermo non compare niente.
Che dovrei fare?
Usare il preprocessore di C?????????????

[andbin]

Originariamente inviato da AMRITA1979
Il problema è che metto printf() dovunque ma sullo schermo non compare niente.
Che dovrei fare?

Mettere fflush(stdout); dopo le printf.

[AMRITA1979]

ho seguito le tue istruzione ma non me le stampa ugualmente
Perchè??????????

[MItaly]

Posta il codice incriminato.

[AMRITA1979]

questo è il main:
int main(int argc, char *argv[])
{
int sockfd;
struct sockaddr_in name;
fd_set active_fd_set, write_fd_set;
int i;
struct sockaddr_in servername;
size_t size;
char command;
char buffer[MAXMSG];
char avgstr[8*trhx_sensors];
long int number;
struct hostent *h;
int st, r;
char n;
unsigned char d;
char m, l;
long timevar;
/* Open syslog*/
openlog("trhxd",LOG_PID | LOG_NDELAY,LOG_DAEMON);
printf("l = %d\n", l);
/* Create socket */
sockfd = socket(PF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
syslog(LOG_ERR,"main: socket() failed");
exit (1);
}
//#ifdef DEBUG
/*printf("connect = %d\n", connect);
printf("LOG_PID = %d\n", LOG_PID);
printf("sockfd = %d\n", sockfd);
printf("r = %d\n", r);
printf("tcpport = %d\n", tcpport);
printf("st = %d\n", st);
printf("syslog = %d\n", syslog);
printf("LOG_ERR = %d\n", LOG_ERR);
printf("servername = %d\n", servername);*/
//printf("l = %d\n", l);
//printf("buffer = %d\n", buffer);
//fflush(stdout);
//#endif
/* Initialize address */
name.sin_family = AF_INET;
name.sin_port = htons (tcpport);
/* extabilish connection */
size = sizeof (servername);
if(connect(sockfd,(struct sockaddr *)&servername, &size) < 0)
{
syslog(LOG_ERR,"main: accept() failed");
exit (1);
}
/* Since the connect call assigns a random address
* to the local end of this connectionm let's use
* getsockname to see waht it assigned.
*/
if (getsockname (sockfd,(struct sockaddr *)&servername, &name) <0)
{
syslog(LOG_ERR,"main: connect() failed");
fprintf(stderr, "%s: unable to read socket address\n", argv[0]);
exit (1);
}
if ((r = read(sockfd, buffer,MAXMSG)) > 0 )
{
buffer[r] = 0;
}
/* Initialize the set of active sockets. */
FD_ZERO (&active_fd_set);
FD_SET (sockfd, &active_fd_set);
while (1)
{
write_fd_set = active_fd_set;
if (terminator)
{
close(sockfd);
exit(0);
}
st=select(FD_SETSIZE, &write_fd_set, NULL, NULL, NULL);
if (st<0)
{
sprintf(buffer,"main: select() failed (error code %d)",errno);
syslog(LOG_ERR,buffer);
exit (1);
}
else
{
/*il client invia i dati a server*/
if (write_to_server (i, &command, &n, &d)<0)
{
close(i);
FD_CLR (i, &active_fd_set);
}
else
{
switch(command)
{
case '?': /* Help */
send(sockfd,"?",10,0);
if(send(sockfd,(struct sockaddr *)&servername,size, 0) !=size)
{
sprintf(buffer,"%s%s\r\n");
}
read_from_server(i, buffer, strlen(buffer));
//printf("\n Help\n");
break;

case 'l': /* Log line & exit */
/*send(sockfd,"l",10,0);
if(send(sockfd,(struct sockaddr *)&servername,size, 0) !=size)
{
sprintf(buffer,"%ld %s", time(NULL), avgstr);
}
recv(sockfd,(struct sockaddr *)&servername, l,0);*/
sprintf(buffer,"%ld %s", time(NULL), avgstr);
read_from_server(i, buffer, strlen(buffer));
close(i);
FD_CLR (i, &active_fd_set);
buffer[0]=0;
//scanf("%d",avgstr[8*trhx_sensors]);
break;
printf("l = %d", l);
fflush(stdout);
default:
sprintf(buffer,"?\r\n");
break;
}
if (st)
{
syslog(LOG_NOTICE,"main: serial I/O failed");
}
if (buffer[0])
{
read_from_server(i, buffer, strlen(buffer));
}
}
}
}

[MItaly]

Usa il tag [code] quando inserisci codice, altrimenti non si vede l'indentazione (e il C senza indentazione è quasi illeggibile).

[AMRITA1979]

int main(int argc, char *argv[])
{
int sockfd;
struct sockaddr_in name;
fd_set active_fd_set, write_fd_set;
int i;
struct sockaddr_in servername;
size_t size;
char command;
char buffer[MAXMSG];
char avgstr[8*trhx_sensors];
long int number;
struct hostent *h;
int st, r;
char n;
unsigned char d;
char m, l;
long timevar;
/* Open syslog*/
openlog("trhxd",LOG_PID | LOG_NDELAY,LOG_DAEMON);
printf("l = %d\n", l);
/* Create socket */
sockfd = socket(PF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
syslog(LOG_ERR,"main: socket() failed");
exit (1);
}
//#ifdef DEBUG
/*printf("connect = %d\n", connect);
printf("LOG_PID = %d\n", LOG_PID);
printf("sockfd = %d\n", sockfd);
printf("r = %d\n", r);
printf("tcpport = %d\n", tcpport);
printf("st = %d\n", st);
printf("syslog = %d\n", syslog);
printf("LOG_ERR = %d\n", LOG_ERR);
printf("servername = %d\n", servername);*/
//printf("l = %d\n", l);
//printf("buffer = %d\n", buffer);
//fflush(stdout);
//#endif
/* Initialize address */
name.sin_family = AF_INET;
name.sin_port = htons (tcpport);
/* extabilish connection */
size = sizeof (servername);
if(connect(sockfd,(struct sockaddr *)&servername, &size) < 0)
{
syslog(LOG_ERR,"main: accept() failed");
exit (1);
}
/* Since the connect call assigns a random address
* to the local end of this connectionm let's use
* getsockname to see waht it assigned.
*/
if (getsockname (sockfd,(struct sockaddr *)&servername, &name) <0)
{
syslog(LOG_ERR,"main: connect() failed");
fprintf(stderr, "%s: unable to read socket address\n", argv[0]);
exit (1);
}
if ((r = read(sockfd, buffer,MAXMSG)) > 0 )
{
buffer[r] = 0;
}
/* Initialize the set of active sockets. */
FD_ZERO (&active_fd_set);
FD_SET (sockfd, &active_fd_set);
while (1)
{
write_fd_set = active_fd_set;
if (terminator)
{
close(sockfd);
exit(0);
}
st=select(FD_SETSIZE, &write_fd_set, NULL, NULL, NULL);
if (st<0)
{
sprintf(buffer,"main: select() failed (error code %d)",errno);
syslog(LOG_ERR,buffer);
exit (1);
}
else
{
/*il client invia i dati a server*/
if (write_to_server (i, &command, &n, &d)<0)
{
close(i);
FD_CLR (i, &active_fd_set);
}
else
{
switch(command)
{
case '?': /* Help */
send(sockfd,"?",10,0);
if(send(sockfd,(struct sockaddr *)&servername,size, 0) !=size)
{
sprintf(buffer,"%s%s\r\n");
}
read_from_server(i, buffer, strlen(buffer));
//printf("\n Help\n");
break;

case 'l': /* Log line & exit */
/*send(sockfd,"l",10,0);
if(send(sockfd,(struct sockaddr *)&servername,size, 0) !=size)
{
sprintf(buffer,"%ld %s", time(NULL), avgstr);
}
recv(sockfd,(struct sockaddr *)&servername, l,0);*/
sprintf(buffer,"%ld %s", time(NULL), avgstr);
read_from_server(i, buffer, strlen(buffer));
close(i);
FD_CLR (i, &active_fd_set);
buffer[0]=0;
//scanf("%d",avgstr[8*trhx_sensors]);
break;
printf("l = %d", l);
fflush(stdout);
default:
sprintf(buffer,"?\r\n");
break;
}
if (st)
{
syslog(LOG_NOTICE,"main: serial I/O failed");
}
if (buffer[0])
{
read_from_server(i, buffer, strlen(buffer));
}
}
}
}

[LexLex]

:quote: :quote: :quote: :quote: :quote: :quote: :quote:

AHAHHAHHHh AHHHahahHaHA H ahA ha hA hAHhAHhah HaHa HaHahHahHhahhHahAH

Mi viene da piangere !!

[Metallica]

Originariamente inviato da LexLex
:quote: :quote: :quote: :quote: :quote: :quote: :quote:

AHAHHAHHHh AHHHahahHaHA H ahA ha hA hAHhAHhah HaHa HaHahHahHhahhHahAH

Mi viene da piangere !!

[mondobimbi]

sei sicura che il socket si apra? Altrimenti il programma ti esce quasi subito.
Stai sicura che la printf funziona, se non ti stampa vuol dire che il programma non raggiunge quel punto, sposta quindi il printf più a monte.
In alternativa puoi usare gdb, un ottimo debugger che ti permette di inserire breakpoint e viewponts.
ciao
sergio