trim.c

#include <stdio.h>

#define NO_OF_PORTS 8
#define TRUE 1
#define FALSE 0

static long pow(int x, int y)
{
    int ii;
    long result = 1;

    for (ii=0; ii<y; ii++)
        result *= x;

    return result;
}

int atoi_fake(const char* string)
{
    int result = 0;
    int ii = 0, cnt = 0;

    for(ii = 0; ii<strlen(string); ii++) {
        if(string[ii] >= '0' && string[ii] <= '9')
            cnt++;
        else
            break;
    }

    for (ii=0; ii<cnt; ii++) {
        result = result + (string[ii]-'0')*pow(10, cnt-ii-1);
    }

    return result;
}

unsigned char trim2int(unsigned char* PortList, const char* szbuf, unsigned short iLen)
{
    unsigned char port = 0;
    unsigned short cnt = 0;
    unsigned short j = 0;
    short iStart;

    iStart = 0;

    for (j=0; j<iLen; j++) {
        if ((szbuf[j] >=  '0' && szbuf[j] <= '9') || szbuf[j]  == ',' || szbuf[j]  == '-') {
            if (szbuf[j] == ',' || (j == iLen - 1) ) {
                port = atoi_fake(szbuf + iStart);
                iStart = j + 1;
                if (port == 0 || port > NO_OF_PORTS || cnt>=NO_OF_PORTS) {
                    return FALSE;
                }
                PortList[cnt] = port;
                cnt++;
            }
        }
    }

    return TRUE;
}

int main(void)
{
    char str[] = "5";
    char portlist[8] = {0};
    char i;

    trim2int(portlist, str, strlen(str));

    for (i=0; i<8; i++)
    {
        if (portlist[i] != 0)
            printf("%d, ", portlist[i]);
    }

    return 0;
}