Struct in C, functions with structs

Question

I have this functions , and i am trying to search in an array in a struct. Now I cant understand where my mistake is, but I believe that is, at the part where function is defined, where I try convert the player country into lowercase.( which in the file holds names of country). when I run the program, and I enter the country name the program just stops and crashes after I enter the name i want to search for.

Anyone can help me? Thank you .

#define NAME_LENGTH 50
#define NUM_PLAYERS 200

struct player_champ
{
    char player_country[NAME_LENGTH];
};

int search_player_by_country( struct player_champ  ptr_player[] , char asked_name[NAME_LENGTH], int lines_got);   
int main (void)    
{
    struct player_champ  player_info[NUM_PLAYERS] = { { 0 } };
    char asked_country[NAME_LENGTH]= {0};

    fflush(stdin);
    printf("\nEnter the name of the country you want to search for.\n\n>>>");
    fgets(asked_country, sizeof(asked_country)-1, stdin);
    asked_country[strlen(asked_country)-1] = '\0';
    search_player_by_country ( player_info, asked_country, num_lines_read);

    int search_player_by_country( struct player_champ ptr_player[] , char asked_country[NAME_LENGTH], int lines_got)
    {
        char temp_asked_country[NAME_LENGTH], temp_country_name[NAME_LENGTH];
        int i,k,z=0,j,counter=0;

        // there is a part of the code here that converts what user entered to lower case as well.

        for (i = 0 ; i < lines_got; i ++)
        {     
            k=0;

            /* while (ptr_player[i].player_country)
            {
                temp_country_name[j] = tolower (ptr_player.player_country);
                j++;
            }*/

            for (k = 0 ; k < lines_got; k ++)
            {
               temp_country_name[k] = tolower (ptr_player[k].player_country);
               k++;
            }
            temp_country_name[k] = '\0';

            if (strstr(temp_country_name, temp_asked_country) != NULL)
            {
               print_info( ptr_player[i]);
            }
        }
    }

@Barmar, at this piece of code it doesn't, but in my program, I think it does because I call scanf and fgets multiply times. — user2512806
– user2512806, Commented Jul 23, 2013 at 4:15
fflush only has an effect on output streams, not input streams. — Barmar
– Barmar, Commented Jul 23, 2013 at 4:16
You didn't initialize ptr_player beyond setting it to empty in this code segment. — abiessu
– abiessu, Commented Jul 23, 2013 at 4:18
also you have nested function definition... mate that code needs house keeping. — yeyo
– yeyo, Commented Jul 23, 2013 at 4:23

Barmar · Accepted Answer · 2013-07-23 04:37:20Z

3

This code is totally wrong:

    for (k = 0 ; k < lines_got; k ++)
    {
        temp_country_name[k] = tolower (ptr_player[k].player_country);
        k++;
    }

You're incrementing k twice -- in the loop header and in the body.
The target of the assignment is a single character in the temp_country_name string, but the parameter to tolower() is an entire string. Aren't you getting a warning from the compiler saying that the parameter to tolower() is the wrong type (it expects a char, you're giving it a char*)?
You're already iterating over lines in the outer loop using i. This loop should just iterate over characters.

Try this:

    for (k = 0 ; ptr_player[i].player_country[k]; k ++)
    {
        temp_country_name[k] = tolower (ptr_player[i].player_country[k]);
    }

ptr_player[i] is the player from element i in the array. player_country[k] is character k in that string. So ptr_player[i].player_country[k] is the k'th character in the i'th player's country.

There are probably other problems in your code, I haven't tried to find them.

edited Jul 23, 2013 at 4:37

answered Jul 23, 2013 at 4:27

Barmar

789k57 gold badges554 silver badges669 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

user2512806 Over a year ago

passing argument 1 of 'tolower' makes integer from pointer without a cast [enabled by default]| this is the warning I get, Yeah you are right about that k++, but if you see there is a while loop commented out, I was trying to use a while loop before.

user2512806 Over a year ago

Would you mind explaining to me, what does:ptr_player[i].player_country[k] do in each places it occurs.

Barmar Over a year ago

I added an explanation.

Amarnath Krishnan Over a year ago

@user2512806 ptr_player[i] points to a player at an instance and ptr_player[i].player_country[k] will point to a players country char sequence.. assumiing you have a player user1 and he is from INDIA.. than ptr_player[0] will point to user1 and ptr_player[0].player_country[0] will point to first character of user1 's country.. (i.e) ptr_player[0].player_country[0] should point to ' I ', ptr_player[0].player_country[1] should point to ' N ' and it goes like this..

user2512806 Over a year ago

@AmarnathKrishnan Yeah, I do understand that part, but why it needs to be on the for loop, inside the parenthesis?

|

Collectives™ on Stack Overflow

Struct in C, functions with structs

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related