Truncation error when receiving a string - c

Question

Ok, so the aim of the game here is for each one of 64 processors (representing an 8x8 grid) to generate a random number (between 0 and 1), and give process zero a string representing the complete situation. For example grid:
[0,1,0,1]
[1,1,1,1]
[0,0,0,0]
would ultimately get have string '0101111000' for a 4x3.
Each process can only communicate with the ones above and to their left.
To do this, I have each process receive a string of all numbers on its right (if it's not on the far right), add its number to the front of the string and send it to the left.
If the process is on the far left, it also receives a string from the process below it (not including bottom left, rank 56), the description of the state of all nodes below that rank .It joins its own value, the left and bottom strings, and sends it up.
All far left nodes begin their row's string.
My attempted code is below:
#include <stdio.h>
#include "mpi.h"
#include <string.h>
#include <stdlib.h>
int farLeft(int rank){// edit
if (rank%8==0){
return 1;
}
return 0;
}
int farRight(int rank){// edit
if (rank%8==7){
return 1;
}
return 0;
}
int main(argc, argv)
int argc;
char **argv;
{
char inputList[100],myWhisp[100],snum[256];
int rank,value;
MPI_Status status;
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
srand(rank);
value = rand() % 2;
sprintf(snum, "%d", value);
strcpy(myWhisp,snum);
if (farLeft(rank)){
MPI_Recv(inputList, strlen(inputList)+1, MPI_CHAR, rank+1, 0, MPI_COMM_WORLD, &status);
strcat(snum,inputList);
strcpy(myWhisp,snum);
if (rank !=56){
MPI_Recv(inputList, strlen(inputList)+1, MPI_CHAR, rank+8, 0, MPI_COMM_WORLD, &status);//rank48 crashes here
strcat(myWhisp,inputList);
}
strcpy(inputList,myWhisp);
if(rank==0){
printf("%s\n",inputList);
}
else{
MPI_Send(inputList, strlen(inputList)+1, MPI_CHAR, rank-8, 0, MPI_COMM_WORLD);
}
}
else if (farRight(rank)){
strcpy(inputList,myWhisp);
MPI_Send(inputList, strlen(inputList)+1, MPI_CHAR, rank-1, 0, MPI_COMM_WORLD);
}
else{
MPI_Recv(inputList, strlen(inputList)+1, MPI_CHAR, rank+1, 0, MPI_COMM_WORLD, &status);
strcat(snum,inputList);
strcpy(inputList,snum);
MPI_Send(inputList, strlen(inputList)+1, MPI_CHAR, rank-1, 0, MPI_COMM_WORLD);
}
MPI_Finalize();
return 0;
}
I'm getting a truncation error with rank 48, the second last rank in the far left. This happens on the receive function below if(rank != 56). So there's something wrong with the way I send/ receive inputString I guess...
Thanks very much.

Answer 1

You're passing the count parameter of MPI_Recv as strlen(inputList)+1, but inputList was never initialised. You probably want sizeof(inputList) here.