구차니의 잡동사니 모음

static int
openredirect(union node *redir)
{
    char *fname;
    int f;

    switch (redir->nfile.type) {
    case NFROM:
        fname = redir->nfile.expfname;
        f = open(fname, O_RDONLY);
        if (f < 0)
            goto eopen;
        break;
    case NFROMTO:
        fname = redir->nfile.expfname;
        f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
        if (f < 0)
            goto ecreate;
        break;
    case NTO:
        /* Take care of noclobber mode. */
        if (Cflag) {
            fname = redir->nfile.expfname;
            f = noclobberopen(fname);
            if (f < 0)
                goto ecreate;
            break;
        }
        /* FALLTHROUGH */
    case NCLOBBER:
        fname = redir->nfile.expfname;
        f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
        if (f < 0)
            goto ecreate;
        break;
    case NAPPEND:
        fname = redir->nfile.expfname;
        f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666);
        if (f < 0)
            goto ecreate;
        break;
    default:
#if DEBUG
        abort();
#endif
        /* Fall through to eliminate warning. */
    case NTOFD:
    case NFROMFD:
        f = -1;
        break;
    case NHERE:
    case NXHERE:
        f = openhere(redir);
        break;
    }

    return f;
 ecreate:
    ash_msg_and_raise_error("cannot create %s: %s", fname, errmsg(errno, "nonexistent directory"));
 eopen:
    ash_msg_and_raise_error("cannot open %s: %s", fname, errmsg(errno, "no such file"));
}