glibc/manual/examples/memopen.c

#include <stdio.h>

static char buffer[] = "foobar";

int
main (void)
{
  int ch;
  FILE *stream;

  stream = fmemopen (buffer, strlen (buffer), "r");
  while ((ch = fgetc (stream)) != EOF)
    printf ("Got %c\n", ch);
  fclose (stream);

  return 0;
}