CODEWITHSUNDEEP
cstringfile
Zerothis
Zerothis

Reputation: 9

How to find a specific string in a file

I have the following file:

username=teste1;
status=ONLINE;
username=teste2;
status=ONLINE;
username=teste3;
status=OFFLINE;

Where one of the lines represents the user name and the bottom line represents the user's status just like above.

I would like to search for a specific username and show its status. But I can't seem to get the right return.

For now I have the following code:

int isUserOnline(char *username) {

    FILE *f;

    f = fopen(FILE_NAME,"r");
    int i = 0;

    char line[MAX] = {'\0'};
    char destiny[MAX] = {'\0'};
    while(!feof(f)) {

        bzero(destiny, sizeof(destiny));

        fgets(line, sizeof(line), f);
        valueAfterEquals(destiny, line);
        if(strcmp(destiny, username)) {
            bzero(destiny, sizeof(destiny));
            fgets(line, sizeof(line), f);
            valueAfterEquals(destiny, line);
            printf("is: %s \n", destiny);
            if(strcmp(destiny, "OFFLINE")) {
                return 1;
            }
            else 
                return 0;
        }
    }
}

The code above should look for the username and check if it exists, if it is offline, return one;

The valueAfterEquals function is, just takes the value after the equal sign and assigns it to a string:

void valueAfterEquals(char * destiny, char * buffer){

    int k = 0;
    while(buffer[k] != '='){ 
        k++;
    }

    int i = 0;
    k++; //pular o '='
    while(buffer[k] != ';'){
        destiny[i] = buffer[k]; 
        k++;
        i++;
    }
}

Upvotes: 0

Views: 100

Answers (1)

KleberPF
KleberPF

Reputation: 120

I suggest using fscanf or sscanf. Consider the following example:

char exampleStr[] = "username=teste1;";
char username[64];
// TO DO: add error checking on sscanf
sscanf(exampleStr, "%*[^=]=%[^;]", username); // username now holds "teste1"
if (strcmp(username, targetUsername) == 0)
{
    // usernames are equal, do whatever you want
}

Upvotes: 1

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