Masking a String (UNIX C)

Posted on 1997-02-25
Last Modified: 2008-02-20
Given a string = "" I want to use another string, mask = "" and mask out the string above.
The result being "".
I want this to work with:

"" mask = ""
To result in: ""
Any Ideas or code that could help ?
Question by:r1ccard0
  • 2

Expert Comment

ID: 1249387
I don't hae any code, but an idea:
1. Split the strings into parts usinf strtok(...)
2. Convert the parts into integers
3. Mask the integers
4. Make a new string using sprintf(...)

Does this help you ?
Regards Michael

Expert Comment

ID: 1249388
Do you still want the code?

Author Comment

ID: 1249389


Accepted Solution

emmons earned 30 total points
ID: 1249390
int main()
char *String1 = "";
char *Mask = "";
char Result[128];
unsigned char Dectets[4], DectMask[4];

StrToNums( String1, Dectets);
StrToNums( Mask, DectMask);
sprintf( Result, "%d.%d.%d.%d",
        Dectets[0] & DectMask[0],
        Dectets[1] & DectMask[1],
        Dectets[2] & DectMask[2],
        Dectets[3] & DectMask[3]);
        printf( "The answer is %s\n", Result);

int StrToNums( char *String1, unsigned char *Num)
int i;
char *next_char;
char number;
unsigned char bin_val;
unsigned char additional;
next_char = String1;

        printf( "%s\n", String1);
        for( i=0; i<4; i++) {
                bin_val = 0;
                while(( number = *next_char++) != '.') {
                        printf( "nextchar = %c\n", number);
                        bin_val *= 10;
                        printf( "1 binval = %d (%o)\n", bin_val, bin_val);
                        additional = number - '0';
                        printf( "additional %d (%o)\n", additional, additional);
                        bin_val += additional;
                        printf( "2 binval = %d (%o)\n", bin_val, bin_val);
                        if( *next_char == '\0') break;
                printf("Result = %d (%o)\n", bin_val, bin_val);
                Num[i] = bin_val;
        printf( "%s = %d-%d-%d-%d\n", String1, Num[0], Num[1], Num[2], Num[3]);


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