Read from serial port only works in main... ??
I am writing code to read from the serial port on my linux machine. I go through the initialization and then when i call read(fd...) in the main function I can read the data correctly. Once I try to pass the fd to another function, so main is short and sweet, the data i get is garbage. I have been struggling with this error for so long that I have even tried doing all the init and reading in the function I want to handle the data and after everything is initialized properly, the read still gives me garbage.
Code:
void sample(int fd)
{
int i;
char* buf = (char*)malloc(128);
for(i=0;i<100;i++) { read(fd, buf, 1); printf("%s", buf); fflush(stdout); }
} // sample
int init(int* fd)
{
struct termios oldtio, newtio;
*fd = open(MODEMDEVICE, O_RDWR | O_NOCTTY);
if (*fd <0) { perror(MODEMDEVICE); exit(-1); }
tcgetattr(*fd,&oldtio); /* save current modem settings */
newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;
newtio.c_iflag = IGNPAR;
newtio.c_oflag = 0;
newtio.c_lflag = 0;
newtio.c_cc[VMIN]=1;
newtio.c_cc[VTIME]=0;
tcflush(*fd, TCIFLUSH);
tcsetattr(*fd,TCSANOW,&newtio);
return(1);
} // init
int main( int argc , char * argv[] )
{
int fd;
char* buf = (char*)malloc(128);
if (!init(&fd))
return 1;
for(i=0;i<100;i++) { read(fd, buf, 1); printf("%s", buf); fflush(stdout); } // works
sample(fd); // fails
close(fd);
} // main
I have printed out both file descriptors before I do my read and they are the same value. So is there something else that is the reason behind my issue?
Thanks,
Chris
