Error Segmentation fault (core dumped) in read and break string code

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I need to read each line of an input file, break it into tokens and save each token in a position of a struct. I am able to do this partially, but at a certain point in the file, Segmentation fault occurs and the program does not read the file completely. I have visited other posts of the site, but I could not solve my problem.

The input and mold file:

RESULTADO,SWIMMING MEN'S 400 M FREESTYLE,OURO,CHINA,PRATA,SOUTH KOREA,BRONZE,UNITED STATES
RESULTADO,SWIMMING WOMEN'S 400 M INDIVIDUAL MEDLEY,OURO,CHINA,PRATA,UNITED STATES,BRONZE,CHINA
RESULTADO,WEIGHTLIFTING WOMEN'S 48 KG,OURO,CHINA,PRATA,JAPAN,BRONZE,NORTH KOREA
CONSULTA,BRAZIL

And the output file (as test), should be the type:

RESULTADO SWIMMING MEN'S 400 M FREESTYLE OURO CHINA PRATA SOUTH KOREA BRONZE UNITED STATES
RESULTADO SWIMMING WOMEN'S 400 M INDIVIDUAL MEDLEY OURO CHINA PRATA UNITED STATES BRONZE CHINA
RESULTADO WEIGHTLIFTING WOMEN'S 48 KG OURO CHINA PRATA JAPAN BRONZE NORTH KOREA
CONSULTA BRAZIL

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

struct Frase{ //struct para guardar os tokens(em pos[40])
struct Linha{
char pos[40];
};
struct Linha teste[10];
};

struct Copia{//struct auxiliar para copia, le as linhas do arquivo de entrada
char frase[200];  
};

struct Frase TOTAL[1000];

void LeArquivo(){
char * valor = (char *) malloc(40);
FILE *arq,*arq1;
int i;
struct Copia vetor[1000];//vetor auxiliar para copia
arq=fopen("teste.txt","r");//arquivo de entrada
arq1=fopen("saida.txt","w");//arquivo usado apenas pra testar se esta lendo corretamente
for(i=0;i<1000;i++){//percorre todos os espaços do vetor, parapoderimprimir no arquivo de saida de teste
while((fgets(vetor[i].frase,sizeof(vetor[i].frase),arq))!=NULL ){

valor = strtok(vetor[i].frase,",");
strcpy(TOTAL[i].teste[0].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[0].pos);

valor = strtok(NULL,",");
strcpy(TOTAL[i].teste[1].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[1].pos);

valor = strtok(NULL,",");
if(valor!=NULL){
strcpy(TOTAL[i].teste[2].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[2].pos);

valor = strtok(NULL,",");
strcpy(TOTAL[i].teste[3].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[3].pos);

valor = strtok(NULL,",");
strcpy(TOTAL[i].teste[4].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[4].pos);

valor = strtok(NULL,",");
strcpy(TOTAL[i].teste[5].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[5].pos);

valor = strtok(NULL,",");
strcpy(TOTAL[i].teste[6].pos,valor);
fprintf(arq1,"%s ",TOTAL[i].teste[6].pos);

valor = strtok(NULL,"\n");
strcpy(TOTAL[i].teste[7].pos,valor);
fprintf(arq1,"%s\n",TOTAL[i].teste[7].pos);  
}

if(strcmp(TOTAL[i].teste[0].pos,"RESULTADO")==0)
{
printf("%s %s %s\n",TOTAL[i].teste[3].pos,TOTAL[i].teste[5].pos,TOTAL[i].teste[7].pos); 
}
else printf("%s \n",TOTAL[i].teste[1].pos);
}}
free(valor);
fclose(arq1);
fclose(arq);
}

int main(){
LeArquivo();
return 0;
}
c string
  • 1

    If you run your program inside a debugger it will be possible to know which line of your program is responsible for the segfault. If you are using an IDE as visualstudio you probably already have a built-in debugger and if you cannot use a command line debugger like gdb.

  • The definition of struct Linha within the struct Frase not cool. Improves code indentation.

1 answer

0

Your immediate problem is in education free(valor);

valor = malloc(40);
for (...) {
    valor = strtok(...); // OOPS, "memory leak"
}
free(valor);             // OOPS, não podes fazer free
                         // a uma memória que não venha de malloc

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