/*
  malloc.c

  demonstrates dynamic memory allocation in C

*/

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

#define BLKSIZ 10


main() {

  FILE *fp;
  char *buf, k;
  int  bufsiz, i;

  // open file for reading
  if (( fp = fopen( "myfile.dat","r" )) == NULL ) {
    perror( "error opening myfile.dat" );
    exit( 1 );
  }

  // allocate memory for input buffer
  bufsiz = BLKSIZ;
  buf = (char *)malloc( sizeof(char)*bufsiz );

  // read contents of file
  i = 0;
  while (( k = fgetc( fp )) != EOF ) {
    buf[i++] = k;
    if ( i == bufsiz ) {
      bufsiz += BLKSIZ;
      buf = (char *)realloc( buf,sizeof(char)*bufsiz );
    }
  }
  if ( i >= bufsiz-1 ) {
    bufsiz += BLKSIZ;
    buf = (char *)realloc( buf,sizeof(char)*bufsiz );
  }
  buf[i] = '\0';

  // output file contents to the screen
  printf( "buf=[%s]\n",buf );

  // close file
  fclose( fp );

} // end main()