Sending Signal to parent doesn´t work - c

Question

I´m trying to make a program that "reveals" MD5 encryption. For that, I´m using a fork().The Parent reads from the file and sends the word readed to the child who process the MD5 and compares it.
The thing is that I want to send back the comparison to the father trough a pipe, I´m trying to do it with signal() but it doesn´t work.
¿Can you give me some help?
My "trash" code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include<sys/types.h>
#include <openssl/md5.h>
#include <unistd.h>
#include<sys/time.h>
#include"semaforo.h"
#include<sys/wait.h>
#include<signal.h>
#define LONG_MAX_LINEA 100
#define NOM_ARCHIVO "commonPass.txt"
int boca2[2];
int flag=0;
void senal(int signumber){
flag=1;
printf("PAR");
return;
}
int main()
{
int boca1[2];
int pid;
char linea[LONG_MAX_LINEA];
char aux;
struct timeval t1;
struct timeval t2;
gettimeofday(&t1, 0);
int cont=0;
FILE* entrada;
int tamLinea;
int tamSalida;
const unsigned char* prueba;
int i;
int andando=1;
unsigned char result[MD5_DIGEST_LENGTH];
int nacimiento;
sem_bin semaforo(true);
int x;
char salida[2];
const unsigned char md50[MD5_DIGEST_LENGTH] = {0xbe, 0x48, 0x44, 0x81, 0x0c, 0xf8, 0xf6, 0x4c, 0x82, 0x0d, 0x71, 0x88, 0x37, 0xc5, 0xf5, 0x3b};
const unsigned char md51[MD5_DIGEST_LENGTH] = {0xb3, 0x40, 0x35, 0xd5, 0x66, 0x44, 0xdb, 0x4a, 0xb8, 0x4f, 0x12, 0x93, 0x63, 0x5f, 0x36, 0x64};
const unsigned char md52[MD5_DIGEST_LENGTH] = {0xf0, 0x4b, 0x5c, 0xaf, 0x6e, 0x61, 0xd9, 0x4c, 0x97, 0x0f, 0x39, 0x2b, 0x13, 0x66, 0x11, 0x18};
const unsigned char md53[MD5_DIGEST_LENGTH] = {0x27, 0x4f, 0x26, 0x46, 0xa2, 0x69, 0xf5, 0x74, 0x12, 0xd5, 0xfc, 0xd3, 0xbf, 0x9d, 0xfd, 0x0c};
const unsigned char md54[MD5_DIGEST_LENGTH] = {0x08, 0x70, 0x28, 0x07, 0xb4, 0xd2, 0xf6, 0x2b, 0x65, 0xbb, 0x74, 0x4d, 0x63, 0x16, 0xd1, 0x41};
const unsigned char md55[MD5_DIGEST_LENGTH] = {0xb8, 0x8f, 0x6a, 0x0f, 0x48, 0xcd, 0x38, 0x30, 0x85, 0x5f, 0x0a, 0xca, 0x82, 0x97, 0xa4, 0x25};
if(pipe(boca1)== -1 || pipe(boca2)==-1){
perror("tuberia");
exit(-1);
}
entrada = fopen(NOM_ARCHIVO, "r");
if (entrada == NULL){
perror(NOM_ARCHIVO);
return EXIT_FAILURE;
}
if(!semaforo.creado()){
perror("No se crea el semaforo");
return EXIT_FAILURE;
}
for(nacimiento=0; nacimiento<1; nacimiento++){
pid=fork();
if(pid==0){
break;
}
}
switch(pid){
case -1: perror("fork");
exit (-1);
case 0:
while(1){
semaforo.wait();
read(boca1[0],&tamLinea, sizeof(int));
read(boca1[0],linea, tamLinea);
semaforo.signal();
linea[tamLinea-1]=0;
tamLinea-=2;
if(strcmp(linea, "exitprimo")==0)
exit(0);
prueba= reinterpret_cast<const unsigned char *>(linea);
MD5(prueba, tamLinea, result);
cont++;
if(!memcmp(result,md50,MD5_DIGEST_LENGTH) || !memcmp(result,md51,MD5_DIGEST_LENGTH)
|| !memcmp(result,md52,MD5_DIGEST_LENGTH) || !memcmp(result,md53,MD5_DIGEST_LENGTH)
|| !memcmp(result,md54,MD5_DIGEST_LENGTH) || !memcmp(result,md55,MD5_DIGEST_LENGTH)){
signal(SIGUSR1,senal);
sleep(1);
}
}
default:
while(1){
fgets(linea, LONG_MAX_LINEA, entrada);
if(feof(entrada)){
for(x=0; x<1; x++){
write(boca1[1],"exitprimo",9);
}
gettimeofday(&t2, NULL);
printf("eso es todo el archivo\n\n");
printf("Tiempo trancurrido: %f seg.\n\n", (double)(t2.tv_usec-t1.tv_usec)/1000000 +
(double)(t2.tv_sec - t1.tv_sec));
exit(0);
}
tamLinea=strlen(linea)+1;
write(boca1[1],&tamLinea, sizeof(int));
write(boca1[1], linea, tamLinea);
}
}
}

Answer 1

tou don't register a signal handler to USR1 so no reason for the function to be called void senal(int signumber)
you can checkout my post, it might help...
https://omerdagan.000webhostapp.com/linux_signal.html
hope that might help... It is also very well documented process on-line
NOTE: I have not looked at the rest of your logic