Fscanf, fprintf and printf

Question

I have a problem with reading and showing on screen. The program it read from the keyboard a series of data, save them in a binary file and then allow the query of how this information is in the bin file, showing them on the screen;

#include <stdio.h>
#include <stdlib.h>


int main(int argc, char **argv)
{

FILE *mestre, *indice;
int opcao, i=0;
int resp = 0, resp4 = 0;

/* lay-out do arquivo mestre */
struct reg_mestre
{   int posicao;
    char nome_pacote[20];
    char destino[15];
    float preco;
    int nr_dias;
    char meio_transporte[15];
 };

struct reg_mestre dados[50];

/* lay-out do arquivo de índices */
struct reg_indice
{   char nome_pacote[20];
    int posicao;
};

struct reg_indice dados2[50];

do {    

    printf ("Bem vindo ao catalogo da agência de viagens!\n");
    printf ("\nO que deseja fazer: \n");
    printf ("\n1 - Adicionar\n");
    printf ("2 - Remover\n");
    printf ("3 - Alterar\n");
    printf ("4 - Exibir todo o Catalogo\n");
    printf ("5 - Consultar um destino específico\n");

    printf("\n\nESCOLHA: ");
    scanf ("%d", &opcao);

    if (opcao == 1){

            mestre = fopen("//home//vitor//Desktop//mestre.bin", "ab");
            indice = fopen("//home//vitor//Desktop//indice.bin", "ab");

            if (mestre){  
                        i++;
                        printf ("--------------------------------------------");
                        printf ("\nPACOTE: %d\n",i); 
                        printf ("\nNome do Pacote: ");
                        __fpurge(stdin); //fflush do linux
                        fflush(stdin); 
                        gets (dados[i].nome_pacote);
                        fflush(stdin);
                        __fpurge(stdin);
                        printf ("Destino: ");
                        fflush(stdin);  
                        __fpurge(stdin);            
                        gets (dados[i].destino);
                        fflush(stdin);
                        __fpurge(stdin); 
                        printf("Preço: ");
                        scanf ("%f", &dados[i].preco);
                        __fpurge(stdin);
                        fflush(stdin); 
                        printf ("Dias: ");
                        scanf ("%d", &dados[i].nr_dias);
                        __fpurge(stdin);
                        fflush(stdin); 
                        printf ("Meios de Transporte: ");
                        __fpurge(stdin);
                        gets (dados[i].meio_transporte);
                        __fpurge(stdin);  
                        fflush(stdin);                      
                        fprintf(mestre,"%s %s %f %d %s\n",dados[i].nome_pacote, dados[i].destino, dados[i].preco, dados[i].nr_dias, dados[i].meio_transporte);
                        fprintf(indice,"%d %s\n", i, dados2[i].nome_pacote); 

                        fclose(mestre); 
                        fclose(indice);
                        printf ("Deseja fazer mais alguma operação? (1 - Sim / 0 - Não): ");
                        scanf ("%d", &resp);
                        if (resp != 0)                  
                            printf ("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
            }

            else {

                 printf ("Erro na abertura do arquivo");
            } 

    }


    else if (opcao == 2 ){

            mestre = fopen("//home//vitor//Desktop//mestre.bin", "wb");
            indice = fopen("//home//vitor//Desktop//indice.bin", "wb");

            if (mestre){ 
                printf("Erro na abertura do arquivo");              
            }
            else {
                    printf ("Deu certo");
                }       
        }


    else if (opcao == 3 ){

            mestre = fopen("//home//vitor//Desktop//mestre.bin", "wb");
            indice = fopen("//home//vitor//Desktop//indice.bin", "wb");

            if (mestre){ 
                printf("Erro na abertura do arquivo");                  
            }

            else {
                    printf("O arquivo abriu!");
            }       
    }

    else if (opcao == 4){

            char ch1[20], ch2[20], ch3[20];
            float fl1;
            int it1;


            mestre = fopen("//home//vitor//Desktop//mestre.bin", "rb");
            indice = fopen("//home//vitor//Desktop//indice.bin", "rb");

            if (mestre){

                while((fscanf(mestre,"%s%s%.2f%.1d%s", ch1, ch2, fl1, it1, ch3))!=EOF ){
                        printf("%s %s %f %d %s \n", ch1, ch2, fl1, it1, ch3);
                }

            }

            else {
                    printf ("O arquivo não existe ou está corrompido.\n");
                    printf ("Deseja fazer mais alguma operação? (1 - Sim / 0 - Não): ");
                    scanf ("%d", &resp4);
                    if (resp4 != 0)                 
                        printf ("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
            }       
        }

    else if (opcao == 5){

            mestre = fopen("//home//vitor//Desktop//mestre.bin", "rb");
            indice = fopen("//home//vitor//Desktop//indice.bin", "rb");

            if (mestre){ 
                printf("Erro na abertura do arquivo");              
            }

            else {
                    printf("O arquivo abriu!");
            }       
        }
    }while (resp != 0 || resp4 != 0);

return 0;

}

The problem is how the results are shown on the screen at the end of the program, they appear like this:

Name of 0.000000 0
Package: Victor 0.000000 0
Figueredo Destination: 0.000000 0
Bahia Price: 0.000000 0
23.000000 Days: 0.000000 0
2 Half 0.000000 0
Transport: 0.000000 0
Plane Transport: 0.000000 0

Could someone explain to me why it is separating the words and what the 0.00000 signiica?

Answer 1

I haven’t been going over your code, but I have two pieces of advice

1) Checks the result of scanf() with the number of assignments

//while((fscanf(mestre,"%s%s%.2f%.1d%s", ch1, ch2, fl1, it1, ch3))!=EOF ){
while(fscanf(mestre,"%s%s%.2f%.1d%s", ch1, ch2, fl1, it1, ch3) == 5) {
/*                                                             ^^^^ */

2) Use string size to avoid buffer overflow

//while((fscanf(mestre,"%s%s%.2f%.1d%s", ch1, ch2, fl1, it1, ch3))!=EOF ){
//while(fscanf(mestre,"%s%s%.2f%.1d%s", ch1, ch2, fl1, it1, ch3) == 5) {
while(fscanf(mestre,"%19s%19s%.2f%.1d%19s", ch1, ch2, fl1, it1, ch3) == 5) {
/*                    ^^  ^^          ^^ */

Answer 2

Use as help this code:

int main () {
FILE * pFile;
long lSize;
char * buffer;
size_t result;

pFile = fopen ( "myfile.bin" , "rb" );
if (pFile==NULL) {fputs ("File error",stderr); exit (1);}

// obtain file size:
fseek (pFile , 0 , SEEK_END);
lSize = ftell (pFile);
rewind (pFile);

// allocate memory to contain the whole file:
buffer = (char*) malloc (sizeof(char)*lSize);
if (buffer == NULL) {fputs ("Memory error",stderr); exit (2);}

// copy the file into the buffer:
result = fread (buffer,1,lSize,pFile);
if (result != lSize) {fputs ("Reading error",stderr); exit (3);}

/* the whole file is now loaded in the memory buffer. */

// terminate
fclose (pFile);
free (buffer);
return 0;
}