从文件中读取二维数组，并在第一行中给出尺寸

Question

I wrote a code to read 2D array of integers from file with dimensions given in the first line . while running it it gives me the following error :

* Error in `./shell': double free or corruption (out): 0x000000000144a0c0 * Aborted (core dumped)

here is my code

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


int main(int argc , char* argv[])
{
FILE * fp;
char * line = NULL;
char * token ;
size_t len = 0;
ssize_t read;
int i;
int j ;
int flag = 0 ;
int row = 0 ;
int **matr ;
char cwd[1024];

getcwd(cwd, sizeof(cwd)) ;
char *matrix = malloc(strlen(cwd)+10);
// here but your file name

asprintf(&matrix,"%s%s",cwd,"/matrix");

fp = fopen(matrix, "r");
if (fp == NULL)
{
    exit(EXIT_FAILURE);
}

while ((read = getline(&line, &len, fp)) != -1)
{

    if(flag == 0)
    {
        token = strtok (line," ");
        i = atoi(token);
        token = strtok (NULL, " ");
        if (token != NULL)
        {
            j = atoi(token);

        }
        printf("%d   %d\n",i,j);
        flag =1 ;
        matr = (int**)malloc(i*sizeof(int*));
        int e ;
        for(e=0; e<=i; e++)
        {
            matr[e] = (int*)malloc(j*sizeof(int));
        }
    }

    else if(row <i)
    {
        int col = 0 ;
        token = strtok (line,"\t");
        while (token != NULL && col<j)
        {
            matr[row][col] = atoi(token);
            printf("%d ",matr[row][col]);
            col++ ;
            token = strtok (NULL,"\t");
        }
        printf("\n");
        row++ ;
    }

  }

fclose(fp);
return 0;
}

any solution ?

Answer 1

the posted code has a unrecoverable memory leak.

the pointer matrix is set to point to some allocated memory by a call to the malloc() function,

Then that pointer is overlayed by the call to asprintf() suggest either using sprintf() or replace the call to malloc() with char *matrix = NULL;