SMS sample code

Hi, i'm not sure is there someone who can help me to correct some sameple code that I found on the web and assembled ? I'm not a programmer, only a unix administrator and of course i'm trying to pickup asap.

The whole idea is I want to have a utility that will allow me to send SMS(short messages) with a GSM modem connected to my linux box. The utility should accept command like "sendsms +6198765432 "This is a simple SMS"

With this code I'm able to do like:

#sendsms ATZ ----to get modem attention.

But how can I make it to be able to make sure of the SendSMS function to be able do like :like "sendsms +6198765432 "This is a simple SMS" ?

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <time.h>

#define BUFSIZE (65536+100)
unsigned char readbuf[BUFSIZE];

static struct termios term;
static struct termios gOriginalTTYAttrs;
int InitConn(int speed);

void SendCmd(int fd, void *buf, size_t size)
{

  if(write(fd, buf, size) == -1) {
    fprintf(stderr, "SendCmd error. %s\n", strerror(errno));
    exit(1);
  }
}

void SendStrCmd(int fd, char *buf)
{
  fprintf(stderr,"Sending command to modem: %s\n",buf);
  SendCmd(fd, buf, strlen(buf));
}

int ReadResp(int fd)
{
  int len = 0;
  struct timeval timeout;
  int nfds = fd + 1;
  fd_set readfds;
  int select_ret;

  FD_ZERO(&readfds);
  FD_SET(fd, &readfds);

  // Wait a second
  timeout.tv_sec = 1;
  timeout.tv_usec = 500000;

  fprintf(stderr,"-");
  while (select_ret = select(nfds, &readfds, NULL, NULL, &timeout) > 0)
  {
    fprintf(stderr,".");
    len += read(fd, readbuf + len, BUFSIZE - len);
    FD_ZERO(&readfds);
    FD_SET(fd, &readfds);
    timeout.tv_sec = 0;
    timeout.tv_usec = 500000;
  }
  if (len > 0) {
    fprintf(stderr,"+\n");
  }
  readbuf[len] = 0;
  fprintf(stderr,"%s",readbuf);
  return len;
}

int InitConn(int speed)
{
  int fd = open("/dev/modem", O_RDWR | O_NOCTTY);

  if(fd == -1) {
    fprintf(stderr, "%i(%s)\n", errno, strerror(errno));
    exit(1);
  }

  ioctl(fd, TIOCEXCL);
  fcntl(fd, F_SETFL, 0);

  tcgetattr(fd, &term);
  gOriginalTTYAttrs = term;

  cfmakeraw(&term);
  cfsetspeed(&term, speed);
  term.c_cflag = CS8 | CLOCAL | CREAD;
  term.c_iflag = 0;
  term.c_oflag = 0;
  term.c_lflag = 0;
  term.c_cc[VMIN] = 0;
  term.c_cc[VTIME] = 0;
  tcsetattr(fd, TCSANOW, &term);

  return fd;
}
void CloseConn(int fd)
{
    tcdrain(fd);
    tcsetattr(fd, TCSANOW, &gOriginalTTYAttrs);
    close(fd);
}

void SendAT(int fd)
{
  char cmd[5];

  //  SendStrCmd(fd, "AT\r");
  sprintf(cmd,"AT\r");
  SendCmd(fd, cmd, strlen(cmd));
}

void AT(int fd)
{
  fprintf(stderr, "Sending command to modem: AT\n");
  SendAT(fd);
  for (;;) {
    if(ReadResp(fd) != 0) {
      if(strstr((const char *)readbuf,"OK") != NULL)
      {
        break;
      }
    }
    SendAT(fd);
  }
}

int SetPDUMode(int fd)
{
    AT(fd);
    SendStrCmd(fd, "ATE0\r");
    ReadResp(fd);
    SendStrCmd(fd, "AT+CMGF=0\r");
    ReadResp(fd);
    if(strstr(readbuf,"OK"))
          return 0;
  return -1;
}

typedef unsigned char        UCHAR;
typedef unsigned char        *LPSTR;
typedef unsigned char        *LPBYTE;
extern LPSTR BinToHex(LPBYTE p, int len);

int SendSMS(int fd, char *to, char *text)
{
    UCHAR buf[200];
    UCHAR at_cmd[1024];
    LPSTR strHex;
    int len;
    int pdu_len;
    int retry = 10;
 
    fd = InitConn(115200);
    SetPDUMode(fd);
    len = ComposeSubmitSms(buf, sizeof(buf), to, NULL, text);
    strHex = BinToHex(buf, len);
    pdu_len = strlen(strHex)/2-1;
    //printf("%d: %s\n",strlen(strHex)/2-1, strHex);
    sprintf(at_cmd,"AT+CMGS=%d\r",pdu_len);
    fprintf(stderr,"S");
    SendStrCmd(fd, at_cmd);
    do{
        len = ReadResp(fd);
    }while(!strstr(readbuf,">") && retry-- > 0);
    if(retry > 0)
    {
        fprintf(stderr,">");
        sprintf(at_cmd,"%s\032",strHex); //CTRL-Z
        SendStrCmd(fd, at_cmd);
        do{
            fprintf(stderr,".");
            len = ReadResp(fd);
        }while(!strstr(readbuf,"+CMGS:") && retry-- > 0);
    }
    if(retry > 0)
    {
        fprintf(stderr,"OK\n");
        CloseConn(fd);
        return 0;//success
    }
    else{
        fprintf(stderr,"%s: %s\n",at_cmd,readbuf);
        free(strHex);
    }
    CloseConn(fd);
    return -1;//failed
}


int main(int argc, char **argv)
{
  int fd;
  char cmd[1024];
  if(argc < 2)
  {
        fprintf(stderr,"usage: %s <at command>\n",argv[0]);
        fprintf(stderr,"examples:\t%s \"AT+XSIMSTATE=1\"\n",argv[0]);
        exit(1);
  }
  fd = InitConn(115200);

  AT(fd);
  sprintf(cmd,"%s\r",argv[1]);
  SendStrCmd(fd,cmd);
  ReadResp(fd);
  CloseConn(fd);
  return 0;
}

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I think you'd have to be a fair bit more specific about what you want help with. What is working, and more importantly what is NOT working, and in what way does it not work?

--
Mats