如何在Linux中使用C ++代码读取AT命令

Question

I wrote the following code in which I am trying to send a message from a SM5100b GSM(which is connected to a Rasberry Pi) to my mobile. It is working but I can check the results of AT commands for example Ok, Ok, +CME ERROR: 4, Ok only when I have Cutecom emulator opened. How can I write a "read" function in this code to give me these results during the compiling line by line? I tried something like out = read(fd, n, sizeof(n)) but I did not have results. I am using Raspian a Debian OS and Codeblocks.

#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 */


int open_port(void)
{
 int fd; /* File descriptor for the port */
 int n,d,e,f,o,out;
 fd = open("/dev/ttyAMA0", O_RDWR | O_NOCTTY | O_NDELAY);
 if (fd == -1)
  {
  /* Could not open the port. */
   perror("open_port: Unable to open /dev/ttyAMA0");
  }
 else
  fcntl(fd, F_SETFL, 0);
  sleep(2);
  n = write(fd, "AT\r\n", 4);
  if (n < 0)
  fputs("write() of 4 bytes failed!\n", stderr);
  sleep(2);

  d = write(fd, "AT+CMGF=1\r", 10);
  if (d < 0)
  fputs("write() of 10 bytes failed!\n", stderr);
  sleep(2);

  e = write(fd, "AT+CMGS=\"6034****\"\r", 20);
  if (e < 0)
  fputs("write() of 20 bytes failed!\n", stderr);
  sleep(2);

  f = write(fd, "hello\r\x1A", 10);
  if (f < 0)
  fputs("write() of 10 bytes failed!\n", stderr);
  sleep(2);

  return (fd);
  }

  int main(void)
  {
  open_port();
  }

Answer 1

You could make a function called like sendAT, which would do something like this:

int sendAT(char* command,int fd) {
  size_t cmdlen = strlen(command);

  int n = write(fd,command, cmdlen);
  if (n != cmdlen)
      return -1
  char reply[40];
  n = read(fd,reply,sizeof(reply));
  reply[n] = 0; //Terminate the string
  if (strcmp(reply, "OK")==0) 
      return 0; //All went well
  else
      return -1; //Some error occurred
}

At the moment you have a lot of duplicated code that does the same thing for every command that you send to the phone.