Материал из C\C++ эксперт
Save array in memory into file
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int i;
double *p;
FILE *fp;
/* get memory */
p = malloc(10 * sizeof(double));
if(!p) {
printf("Allocation Error");
exit(1);
}
/* generate 10 random numbers */
for(i = 0; i < 10; i++)
p[i] = (double) rand();
if((fp = fopen("my.txt", "wb")) == NULL) {
printf("Cannot open file.\n");
exit(1);
}
/* write the entire array in one step */
if( fwrite(p, 10*sizeof(double), 1, fp) != 1) {
printf("Write Error.\n");
exit(1);
}
fclose(fp);
free(p); /* free memory */
/* get memory again */
p = malloc(10 * sizeof(double));
if(!p) {
printf("Allocation Error");
exit(1);
}
if((fp = fopen("my.txt", "rb"))==NULL) {
printf("Cannot open file.\n");
exit(1);
}
/* read the entire array in one step */
if(fread(p, 10 * sizeof( double ), 1, fp) != 1) {
printf( " Read Error.\n " );
exit( 1 );
}
fclose( fp );
/* display the array */
for(i = 0; i < 10; i++)
printf("%f ", p[ i ]);
free(p);
return 0;
}
