Thread: I need help please...my program is crashing

Hi I'm a student and my professor want us to make a C program in LINUX in wich the parent process generates two child processes. The parent will read data from stdin and will send it to his children.

The 1st child will show on screen the text read from his father,to standard output.

The 2nd child will show the read data in a file. When the parent has as input an "exit", he will send termination signals to his children and will exit.

So here I let you the code I did and the errors I get when I have to compile. The teacher want us to program it like the way is shown below , with that structure.

The program is in spanish, so the variable names too,I hope that won't be a problem and you can help me as soon as posible because I'm desperate...THANK YOU!!!!

Code:

 
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>


int pidHijo1; // global var for 1st child
int descrTub1[2]; //global var for 1st pipe

int pidHijo2; //global var for 2nd child
int descrTub2[2]; //global var for 2nd pipe


char bufferLectura[256]; //buffer



void ProcesoHijo1(); //1st child process
void ProcesoHijo2(); //2nd child process
void ProcesoPadre(); //parent process


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


pipe(descrTub1); 

pidHijo1 = fork();

if (pidHijo1 == 0) {
ProcesoHijo1();
return 0;
}


pidHijo2 = fork();

if (pidHijo2 == 0)
ProcesoHijo2();
else
ProcesoPadre();


}

void ProcesoHijo1() { 

close(0); 
dup(descrTub1[0]); 
while (1) { 
fgets(bufferLectura, 255, stdin); 
printf("%s\n", bufferLectura);
}
}

void ProcesoHijo2() { 
int descrFichero;

close(0); 
dup(descrTub1[0]); 

descrFichero = open("salida.txt", O_RDWR | O_TRUNC, 0600);

while(1) { 
fgets(bufferLectura,255,descrTub1[0]); 
write(descrFichero, bufferLectura, strlen(bufferLectura));
}


}

void ProcesoPadre() { 


close(2); 
dup(descrTub1[1]); 

printf("[Proceso padre] Introduce un texto, o exit para salir> ");
fgets(bufferLectura, 255);

while(strcmp(bufferLectura, "exit")) { 

fprintf(stderr, bufferLectura); 
write(descrTub2[0], bufferLectura, strlen(bufferLectura)); 

printf("<[Proceso padre] Introduce un texto, o exit para salir> "); //[Parent Process] Insert text or exit
fgets(bufferLectura, 255);
}


kill(pidHijo1, SIGTERM);
kill(pidHijo2, SIGTERM);


}

ERRORS:

ejercicio.c: In function ‘ProcesoHijo2’:
ejercicio.c:71: warning: passing argument 3 of ‘fgets’ makes pointer from integer without a cast
/usr/include/stdio.h:624: note: expected ‘struct FILE * __restrict__’ but argument is of type ‘int’
ejercicio.c:72: warning: incompatible implicit declaration of built-in function ‘strlen’
ejercicio.c: In function ‘ProcesoPadre’:
ejercicio.c:85: error: too few arguments to function ‘fgets’
ejercicio.c:89: warning: format not a string literal and no format arguments
ejercicio.c:90: warning: incompatible implicit declaration of built-in function ‘strlen’
ejercicio.c:93: error: too few arguments to function ‘fgets’

Originally Posted by Adak

This is correct - note that it has the file pointer as the third parameter for fgets(). Your other fgets() calls, do not have that.

Code:

fgets(bufferLectura, 255, stdin);

I can't help you with a lot of this, but this is a few of your errors.

ejercicio.c:71: warning: passing argument 3 of ‘fgets’ makes pointer from integer without a cast
/usr/include/stdio.h:624: note: expected ‘struct FILE * __restrict__’ but argument is of type ‘int’
ejercicio.c:85: error: too few arguments to function ‘fgets’
ejercicio.c:93: error: too few arguments to function ‘fgets’


Looks like you have not yet included string.h, if you want to use strlen(), you'll want it.

Wow GOD BLESS YOU!!! my errors have decreased because of that (string.h). Yes,I know those others are my errors, but the thing is that the professor told us to program this without knowing C, and without teaching it...so I'm getting a "little bit" crazy because of that... So,I have trouble with fgets and I don't know what to do, but you helped me anyway MANY THANKS.

Is it just me or are we experiencing an epidemic of people who don't know how to indent code?

Looks like their first time swimming in the pool, instead of practicing their swimming on the deck.