Find Student Function

a function that searchs a student in database and returns his file name

findStudent() is a function that searches for a student's file in the database based on their name. And we're going to explain it

1. Function Definition:

char* findStudent(char* nom, char* prenom)

• This function takes two arguments: nom and prenom, which represent the last name and first name of the student, respectively.

• The function returns a char* pointer, which points to the file path of the student's record if found, or NULL if not found.

Code snippet:

char* findStudent(char* nom, char* prenom) {
    char option1[100];
    char option2[100];
    FILE* tmp1;
    FILE* tmp2;

    sprintf(option1, "database/%s_%s.txt", nom, prenom);
    sprintf(option2, "database/%s_%s.txt", prenom, nom);

    tmp1 = fopen(option1, "r");
    tmp2 = fopen(option2, "r");

    if (tmp1 != NULL) {
        fclose(tmp1);
        if (tmp2 != NULL) {
            fclose(tmp2);
        }
        char* result = malloc(strlen(option1) + 1); // Allocate memory for the result
        strcpy(result, option1); // Copy option1 to result
        return result;
    } else if (tmp2 != NULL) {
        fclose(tmp2);
        char* result = malloc(strlen(option2) + 1); // Allocate memory for the result
        strcpy(result, option2); // Copy option2 to result
        return result;
    }

    return NULL;
}

2. Variable Declarations:

char option1[100];
char option2[100];
FILE* tmp1;
FILE* tmp2;

Variable	Description
option1 and option2	character arrays used to store the two possible file paths for the student's record based on the provided names.
tmp1 and tmp2	file pointers used to check if the corresponding files exist.

3. Function Tasks:

3.1 Generating File Paths:

sprintf(option1, "database/%s_%s.txt", nom, prenom);
sprintf(option2, "database/%s_%s.txt", prenom, nom);

• These lines use sprintf to generate the file paths by concatenating the provided names with the "database/" directory path.

3.2 Opening Files:

tmp1 = fopen(option1, "r");
tmp2 = fopen(option2, "r");

• These lines attempt to open the files using the generated file paths for reading ("r" mode).

• tmp1 is used to check if the file with the nom_prenom.txt naming scheme exists.

• tmp2 is used to check if the file with the prenom_nom.txt naming scheme exists.

3.3 File Existence Checking:

if (tmp1 != NULL) {
    fclose(tmp1);
    if (tmp2 != NULL) {
        fclose(tmp2);
    }
    char* result = malloc(strlen(option1) + 1); // Allocate memory for the result
    strcpy(result, option1); // Copy option1 to result
    return result;
} else if (tmp2 != NULL) {
    fclose(tmp2);
    char* result = malloc(strlen(option2) + 1); // Allocate memory for the result
    strcpy(result, option2); // Copy option2 to result
    return result;
}

• If tmp1 is not NULL, it means that the file with the nom_prenom.txt naming scheme so function returns it.

• Else if tmp2 is not NULL, it means that the file with prenom_nom.txt naming scheme so function returns it.

• Otherwice, both doesn't exist so function will return NULL.