uart_main.c

//
#include <stdio.h>
#include <conio.h>
#include "uart_win32.h"

#define dbg_printf //printf

static bool hex = false;
static void on_comm_read(uart_obj *uart, const char *buf, const int l)
{
    static int counter = 0;
    if (l < 1) return;

    if (hex)
    {
        unsigned char *s = (unsigned char *)buf;
        for (int i = 0; i < l; i++)
        {
            printf("%02X ", s[i]);
            counter++;
            if (counter % 32 == 0) printf("\n");
        }
    }
    else
    {
        static char s[20 * 1024];
        memcpy(s, buf, min(sizeof(s) - 1, l));
        s[l] = '\0';
        printf(s);
    }
}

static void on_comm_close(uart_obj *uart, const enum_comm_close reason)
{
    dbg_printf("COM closed: %s\n", reason == cc_shutdown ? "shutdown" : "error");
    exit(0);
}

void help()
{
    printf("UART util command line options:\n");
    printf("UART port options:\n");
    printf("\t -port      <integer>                     (mandatory)\n");
    printf("\t -baud      <integer>\n");
    printf("\t -databits  <integer>\n");
    printf("\t -stopbits  <integer>\n");
    printf("\t -parity    none | even | odd | mark | space\n");
    printf("Common options:\n");
    printf("\t -help/-?                                 show this\n");
    printf("\t -hex       use hex display\n");
    printf("\t -cr        cr | lf | crlf | lfcr         default: cr\n");
    printf("\t -input     string | char \n"
           "\n"
           "Note: string: based on 'gets' (default),\n"
           "              can use UP/DOWN to access input history\n"
           "      char  : based on 'getch' (low level)");
}

static uart_obj uart;
static char     cr[3] = {'\r', '\0'};
static bool     use_getch = false;

void interact_direct();
void interact_str();
BOOL ctrl_handler(DWORD fdwCtrlType);

int uart_main(const int argc, const char *args[])
{   
    int port = -1;
    int baud = -1;
    char parity[20] = {'\0'};
    int  databits = -1;
    int  stopbits = -1;

#define load_i_param(param) \
    if (strcmp(args[i], "-"#param) == 0)   \
    {   param = atoi(args[i + 1]); i += 2; }

#define load_b_param(param) \
    if (strcmp(args[i], "-"#param) == 0)   \
    {   param = true; i++; }    

    if (argc < 2)
    {
        help();
        return -1;
    }

    int i = 1;
    while (i < argc - 1)
    {
        load_i_param(port)
        else load_i_param(baud)
        else load_i_param(databits)
        else load_i_param(stopbits)
        else load_b_param(hex)
        else if ((strcmp(args[i], "-?") == 0) || (strcmp(args[i], "-help") == 0))
        {
            help();
            return -1;
        }
        else if (strcmp(args[i], "-cr") == 0)
        {
            if (strcmp(args[i + 1], "cr") == 0) strcpy(cr, "\r");
            else if (strcmp(args[i + 1], "lf") == 0) strcpy(cr, "\n");
            else if (strcmp(args[i + 1], "crlf") == 0) strcpy(cr, "\r\n");
            else if (strcmp(args[i + 1], "lfcr") == 0) strcpy(cr, "\r\r");
            i += 2;
        }
        else if (strcmp(args[i], "-input") == 0)
        {
            if (strcmp(args[i + 1], "string") == 0) use_getch = false;
            else if (strcmp(args[i + 1], "char") == 0) use_getch = true;
            i += 2;
        }
        else if (strcmp(args[i], "-parity") == 0)
        {
            strncpy(parity, args[i + 1], 19);
            i += 2;
        }
        else
            i++;
    }

    if (port < 0)
    {
        fprintf(stderr, "Port unspecified\n");
        return -1;
    }

    if (uart_open(&uart, 
                  port, 
                  baud, 
                  parity, 
                  databits, 
                  stopbits, 
                  f_on_comm_read(on_comm_read),
                  &uart,
                  f_on_comm_close(on_comm_close),
                  &uart) == NULL) 
    {
        fprintf(stderr, "Failed to open the specified port COM%d\n", port);
        return -1;
    }
    else
    {
        fprintf(stderr, "Port COM%d is opened. Input mode: %s\n", port, use_getch ? "CHAR" : "STRING");
        fprintf(stderr, "Use Ctrl+C to close port and exit.\n");
    }

    if (!SetConsoleCtrlHandler((PHANDLER_ROUTINE)ctrl_handler, TRUE))
        fprintf(stderr, "WARNING: SetConsoleCtrlHandler failed.\n");
    
    if (use_getch)
        interact_direct();
    else
        interact_str();
}

void interact_str()
{
    char s[10240 + 1];
    while (true)
    {        
        s[0] = '\0';
        gets(s);
        if (strlen(s) >= sizeof(s) - 1)
        {
            uart_shutdown(&uart);
            break;
        }

        strcat(s, cr);
        uart_send(&uart, s, strlen(s));
    }
}

void interact_direct()
{
    while (true)
    {
        char ch = getch();
        
        // although it is said that getch can't be used to capture Ctrl+C
        if (ch == 3)
        {
            dbg_printf("Ctrl+C: breaking...\n");
            uart_shutdown(&uart);
            break;
        }

        if (ch == '\r')
            uart_send(&uart, cr, strlen(cr));
        else
            uart_send(&uart, &ch, 1);

        putchar(ch);
    }
}

BOOL ctrl_handler(DWORD fdwCtrlType) 
{ 
    switch (fdwCtrlType) 
    {
        case CTRL_C_EVENT: 
            uart_shutdown(&uart);
            return TRUE;
  
        case CTRL_BREAK_EVENT: 
            return FALSE; 

        // console close/logoff/shutdown
        case CTRL_CLOSE_EVENT: 
        case CTRL_LOGOFF_EVENT: 
        case CTRL_SHUTDOWN_EVENT:
            uart_shutdown(&uart);
            return FALSE; 

        default: 
            return FALSE; 
    } 
}