CODEWITHSUNDEEP
c
Allemis
Allemis

Reputation: 57

C: strtod loop, counting white spaces

I´m having some troubles with my C project. I read a line using fgets(line, 1024, stdin). In the line, there should be exactly 4 arguments separated by white spaces, if not, the program should write a warning. Something like this:

"1f 2 4 34" --> "ok"
"af b v" --> "warning"
"a bbgd c v d" --> "warning"

I was thinking of using a "strtod" function loop, however I´m not sure how. This is my idea:

    char * ptr;
    int i = 0;
    ptr= strtok (line," ");
    while (ptr!= NULL) /*I would like to count the white spaces*/
    {
        i++;
        ptr= strtok (NULL, " "); /*I suppose this part is not correct*/
    }

    if(i != 3) /*3 white spaces --> 4 arguments*/
    {...}

Thank you for any answer.

Upvotes: 0

Views: 256

Answers (1)

Oldest Software Guy
Oldest Software Guy

Reputation: 741

$ man strtok

is your friend. The routine eats all occurrences of the delimiter group and returns the address of a null-terminated string.

Don't try to count the spaces, count the number of times strtok(3) returns a non-null value.

Upvotes: 1

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