+int filename_equal(const Filename *f1, const Filename *f2)
+{
+ return !strcmp(f1->path, f2->path);
+}
+
+int filename_is_null(const Filename *fn)
+{
+ return !fn->path[0];
+}
+
+void filename_free(Filename *fn)
+{
+ sfree(fn->path);
+ sfree(fn);
+}
+
+int filename_serialise(const Filename *f, void *vdata)
+{
+ char *data = (char *)vdata;
+ int len = strlen(f->path) + 1; /* include trailing NUL */
+ if (data) {
+ strcpy(data, f->path);
+ }
+ return len;
+}
+Filename *filename_deserialise(void *vdata, int maxsize, int *used)
+{
+ char *data = (char *)vdata;
+ char *end;
+ end = memchr(data, '\0', maxsize);
+ if (!end)
+ return NULL;
+ end++;
+ *used = end - data;
+ return filename_from_str(data);
+}
+
+#ifdef DEBUG
+static FILE *debug_fp = NULL;
+
+void dputs(char *buf)
+{
+ if (!debug_fp) {
+ debug_fp = fopen("debug.log", "w");
+ }
+
+ write(1, buf, strlen(buf));
+
+ fputs(buf, debug_fp);
+ fflush(debug_fp);
+}
+#endif
+
+char *get_username(void)
+{
+ struct passwd *p;
+ uid_t uid = getuid();
+ char *user, *ret = NULL;
+
+ /*
+ * First, find who we think we are using getlogin. If this
+ * agrees with our uid, we'll go along with it. This should
+ * allow sharing of uids between several login names whilst
+ * coping correctly with people who have su'ed.
+ */
+ user = getlogin();
+ setpwent();
+ if (user)
+ p = getpwnam(user);
+ else
+ p = NULL;
+ if (p && p->pw_uid == uid) {
+ /*
+ * The result of getlogin() really does correspond to
+ * our uid. Fine.
+ */
+ ret = user;
+ } else {
+ /*
+ * If that didn't work, for whatever reason, we'll do
+ * the simpler version: look up our uid in the password
+ * file and map it straight to a name.
+ */
+ p = getpwuid(uid);
+ if (!p)
+ return NULL;
+ ret = p->pw_name;
+ }
+ endpwent();
+
+ return dupstr(ret);
+}
+
+/*
+ * Display the fingerprints of the PGP Master Keys to the user.
+ * (This is here rather than in uxcons because it's appropriate even for
+ * Unix GUI apps.)
+ */
+void pgp_fingerprints(void)
+{
+ fputs("These are the fingerprints of the PuTTY PGP Master Keys. They can\n"
+ "be used to establish a trust path from this executable to another\n"
+ "one. See the manual for more information.\n"
+ "(Note: these fingerprints have nothing to do with SSH!)\n"
+ "\n"
+ "PuTTY Master Key (RSA), 1024-bit:\n"
+ " " PGP_RSA_MASTER_KEY_FP "\n"
+ "PuTTY Master Key (DSA), 1024-bit:\n"
+ " " PGP_DSA_MASTER_KEY_FP "\n", stdout);
+}
+
+/*
+ * Set and clear fcntl options on a file descriptor. We don't
+ * realistically expect any of these operations to fail (the most
+ * plausible error condition is EBADF, but we always believe ourselves
+ * to be passing a valid fd so even that's an assertion-fail sort of
+ * response), so we don't make any effort to return sensible error
+ * codes to the caller - we just log to standard error and die
+ * unceremoniously. However, nonblock and no_nonblock do return the
+ * previous state of O_NONBLOCK.
+ */
+void cloexec(int fd) {
+ int fdflags;
+
+ fdflags = fcntl(fd, F_GETFD);
+ if (fdflags < 0) {
+ fprintf(stderr, "%d: fcntl(F_GETFD): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+ if (fcntl(fd, F_SETFD, fdflags | FD_CLOEXEC) < 0) {
+ fprintf(stderr, "%d: fcntl(F_SETFD): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+}
+void noncloexec(int fd) {
+ int fdflags;
+
+ fdflags = fcntl(fd, F_GETFD);
+ if (fdflags < 0) {
+ fprintf(stderr, "%d: fcntl(F_GETFD): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+ if (fcntl(fd, F_SETFD, fdflags & ~FD_CLOEXEC) < 0) {
+ fprintf(stderr, "%d: fcntl(F_SETFD): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+}
+int nonblock(int fd) {
+ int fdflags;
+
+ fdflags = fcntl(fd, F_GETFL);
+ if (fdflags < 0) {
+ fprintf(stderr, "%d: fcntl(F_GETFL): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+ if (fcntl(fd, F_SETFL, fdflags | O_NONBLOCK) < 0) {
+ fprintf(stderr, "%d: fcntl(F_SETFL): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+
+ return fdflags & O_NONBLOCK;
+}
+int no_nonblock(int fd) {
+ int fdflags;
+
+ fdflags = fcntl(fd, F_GETFL);
+ if (fdflags < 0) {
+ fprintf(stderr, "%d: fcntl(F_GETFL): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+ if (fcntl(fd, F_SETFL, fdflags & ~O_NONBLOCK) < 0) {
+ fprintf(stderr, "%d: fcntl(F_SETFL): %s\n", fd, strerror(errno));
+ exit(1);
+ }
+
+ return fdflags & O_NONBLOCK;
+}
+
+FILE *f_open(const Filename *filename, char const *mode, int is_private)