#include <stdio.h>
#include <errno.h>
#include <string.h>

char buf[BUFSIZ];

static void write_text(const char *text, FILE *stream)
{
    size_t len;
    size_t written;

    len = strlen(text);
    written = fwrite(text, 1, len, stream);
    printf("fwrite(%s) => %zu bytes written/%zu [errno=%i, ferror=%i]\n",
           text, written, len, errno, ferror(stream));
}


int main(int argc, char ** argv)
{
    int n;
    FILE *f;

    f = fopen("/dev/full", "w");
#if 0
    n = setvbuf(f, (char *) NULL, _IOLBF, 0);
    printf("setvbuf(NULL) => %i [errno=%d]\n", n, errno);
#elif 0
    n = setvbuf(f, (char *) buf, _IOLBF, BUFSIZ);
    printf("setvbuf(%zd bytes) => %i [errno=%d]\n", BUFSIZ, n, errno);
#endif

#if 0
    /* works correctly */
    write_text("hello", f);
    write_text("\n", f);
#else
    write_text("hello\n", f);
#endif

#if 0
    n = fflush(f);
    printf("fflush() => %i [errno=%d]\n", n, errno);
#endif

#if 0
    write_text("a", f);
#endif

    n = fclose(f);
    printf("fclose() => %i [errno=%d]\n", n, errno);

    return 0;
}