问题
I am using serial programming for get connected serial cable to my iPhone
my code is as under
#include <stdio.h> /* Standard input/output definitions */
#include <string.h> /* String function definitions */
#include <unistd.h> /* UNIX standard function definitions */
#include <fcntl.h> /* File control definitions */
#include <errno.h> /* Error number definitions */
#include <termios.h> /* POSIX terminal control definitions */
static struct termios gOriginalTTYAttrs;
static int OpenSerialPort()
{
int fileDescriptor = -1;
int handshake;
struct termios options;
// Open the serial port read/write, with no controlling terminal, and don't wait for a connection.
// The O_NONBLOCK flag also causes subsequent I/O on the device to be non-blocking.
// See open(2) ("man 2 open") for details.
fileDescriptor = open("/dev/tty.iap", O_RDWR | O_NOCTTY | O_NONBLOCK);
if (fileDescriptor == -1)
{
printf("Error opening serial port %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Note that open() follows POSIX semantics: multiple open() calls to the same file will succeed
// unless the TIOCEXCL ioctl is issued. This will prevent additional opens except by root-owned
// processes.
// See tty(4) ("man 4 tty") and ioctl(2) ("man 2 ioctl") for details.
if (ioctl(fileDescriptor, TIOCEXCL) == -1)
{
printf("Error setting TIOCEXCL on %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Now that the device is open, clear the O_NONBLOCK flag so subsequent I/O will block.
// See fcntl(2) ("man 2 fcntl") for details.
if (fcntl(fileDescriptor, F_SETFL, 0) == -1)
{
printf("Error clearing O_NONBLOCK %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Get the current options and save them so we can restore the default settings later.
if (tcgetattr(fileDescriptor, &gOriginalTTYAttrs) == -1)
{
printf("Error getting tty attributes %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// The serial port attributes such as timeouts and baud rate are set by modifying the termios
// structure and then calling tcsetattr() to cause the changes to take effect. Note that the
// changes will not become effective without the tcsetattr() call.
// See tcsetattr(4) ("man 4 tcsetattr") for details.
options = gOriginalTTYAttrs;
// Print the current input and output baud rates.
// See tcsetattr(4) ("man 4 tcsetattr") for details.
printf("Current input baud rate is %d\n", (int) cfgetispeed(&options));
printf("Current output baud rate is %d\n", (int) cfgetospeed(&options));
// Set raw input (non-canonical) mode, with reads blocking until either a single character
// has been received or a one second timeout expires.
// See tcsetattr(4) ("man 4 tcsetattr") and termios(4) ("man 4 termios") for details.
cfmakeraw(&options);
options.c_cc[VMIN] = 1;
options.c_cc[VTIME] = 10;
// The baud rate, word length, and handshake options can be set as follows:
cfsetspeed(&options, B19200); // Set 19200 baud
options.c_cflag |= (CS8); // RTS flow control of input
printf("Input baud rate changed to %d\n", (int) cfgetispeed(&options));
printf("Output baud rate changed to %d\n", (int) cfgetospeed(&options));
// Cause the new options to take effect immediately.
if (tcsetattr(fileDescriptor, TCSANOW, &options) == -1)
{
printf("Error setting tty attributes %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Success
return fileDescriptor;
// Failure "/dev/tty.iap"
error:
if (fileDescriptor != -1)
{
close(fileDescriptor);
}
return -1;
}
int main(int args, char *argv[])
{
int fd;
char somechar[8];
fd=OpenSerialPort(); // Open tty.iap with no hardware control, 8 bit, BLOCKING and at 19200 baud
if(fd>-1)
{
write(fd,"*",1); // Write handshaking message over serial
///////////////////////////////////////////////////////////////////////////////////////////////////
// After this, our device or our PC program should be strobing serial ground to gain access to the Iphone Serial Line
//////////////////////////////////////////////////////////////////////////////////////////////////
read(fd,&somechar[0],1); // Read 1 byte over serial. This will block (wait) untill the byte has been received
if(somechar[0]=='*') // Check if this byte is a "handshaking" message
{
printf("Serial connection established!\n"); // If it is, we have established a connection to the device and can freely read/write over serial!
while(1) // Do this forever or untill someone presses CTRL+C
{
read(fd,&somechar[0],1); // Read a character over serial!
putchar(somechar[0]); // Write the character to the Terminal!!
}
}
}
return 0;
}
but when i am going to check the cable is connected or not i got one Error like this
Error opening serial port /dev/tty.iap - Operation not permitted(1).
is there any one know the solution and please give me suggestion if i am going in wrong way actually i am a new in iOS development so more confused.
Thanks
回答1:
Perhaps the following articles iPhone Serial Communication may help?
iPhone/iPod Touch Serial Port Tutorial By Collin Meyer
and
iPhone Serial Communication
回答2:
I got the same error when trying to open the serial port on a jailbroken iPod Touch running iOS 5.0 using a binary created with Xcode. However when I used gcc (for the iPhone with appropriate flags set) on the command line on my Mac instead of Xcode and created a command line app for iOS, the binary that was generated was able to open the serial port and read commands from my external accessory. This should be possible to create a library and link it with Xcode and have the same result (though I haven't tried it yet).
Update: Unfortunately creating a library in gcc and linking it in an Xcode project came up with the same error as before. Possible solutions:
- call the command line app from the iOS Xcode GUI app
- compile the app itself with
gccinstead of Xcode
Actually, it's even simpler than this, found it while going through the second link in Fulvio's answer: You just need to move the app to a different directory than where Xcode normally puts them. As suggested in the blog entry, I put my app in a directory for Cydia apps (/private/var/stash/Applications), and was able to open the serial port--no gcc compiling necessary.
So my gcc-compiled command-line app was able to read from the serial port because I was executing it in the root's home directory, which also doesn't have the restrictions of the normal apps directory (/private/var/mobile/Applications)--whatever those restrictions might be.
来源：https://stackoverflow.com/questions/7608001/connect-the-accessory-to-my-jailbreak-iphone-device