+ * "" -> []
+ * "\n" -> [""]
+ * "a\nb" -> ["a"; "b"]
+ * "a\nb\n" -> ["a"; "b"]
+ * "a\nb\n\n" -> ["a"; "b"; ""]
+ *
+ * The original string is written over and destroyed by this
+ * function (which is usually OK because it's the 'out' string
+ * from command()). You can free the original string, because
+ * add_string() strdups the strings.
+ */
+char **
+split_lines (char *str)
+{
+ char **lines = NULL;
+ int size = 0, alloc = 0;
+ char *p, *pend;
+
+ if (strcmp (str, "") == 0)
+ goto empty_list;
+
+ p = str;
+ while (p) {
+ /* Empty last line? */
+ if (p[0] == '\0')
+ break;
+
+ pend = strchr (p, '\n');
+ if (pend) {
+ *pend = '\0';
+ pend++;
+ }
+
+ if (add_string (&lines, &size, &alloc, p) == -1) {
+ return NULL;
+ }
+
+ p = pend;
+ }
+
+ empty_list:
+ if (add_string (&lines, &size, &alloc, NULL) == -1)
+ return NULL;
+
+ return lines;
+}
+
+/* printf helper function so we can use %Q ("quoted") and %R to print
+ * shell-quoted strings. See HACKING file for more details.
+ */
+static int
+print_shell_quote (FILE *stream,
+ const struct printf_info *info ATTRIBUTE_UNUSED,
+ const void *const *args)
+{
+#define SAFE(c) (c_isalnum((c)) || \
+ (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.')
+ int i, len;
+ const char *str = *((const char **) (args[0]));
+
+ for (i = len = 0; str[i]; ++i) {
+ if (!SAFE(str[i])) {
+ putc ('\\', stream);
+ len ++;
+ }
+ putc (str[i], stream);
+ len ++;
+ }
+
+ return len;
+}
+
+static int
+print_sysroot_shell_quote (FILE *stream,
+ const struct printf_info *info,
+ const void *const *args)
+{
+ fputs (sysroot, stream);
+ return sysroot_len + print_shell_quote (stream, info, args);
+}
+
+#ifdef HAVE_REGISTER_PRINTF_SPECIFIER
+static int
+print_arginfo (const struct printf_info *info ATTRIBUTE_UNUSED,
+ size_t n, int *argtypes, int *size)
+{
+ if (n > 0) {
+ argtypes[0] = PA_STRING;
+ size[0] = sizeof (const char *);
+ }
+ return 1;
+}
+#else
+#ifdef HAVE_REGISTER_PRINTF_FUNCTION
+static int
+print_arginfo (const struct printf_info *info, size_t n, int *argtypes)
+{
+ if (n > 0)
+ argtypes[0] = PA_STRING;
+ return 1;
+}
+#else
+#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined"
+#endif
+#endif
+
+/* Perform device name translation. Don't call this directly -
+ * use the RESOLVE_DEVICE macro.
+ *
+ * See guestfs(3) for the algorithm.
+ *
+ * We have to open the device and test for ENXIO, because
+ * the device nodes themselves will exist in the appliance.