+ return 1;
+}
+
+FILE *ask_and_safe_open(const char* filename, const char* what, const char* mode)
+{
+ FILE *r;
+ char *directory;
+ char *fn;
+
+ /* Check stdin and stdout */
+ if(!isatty(0) || !isatty(1))
+ {
+ /* Argh, they are running us from a script or something. Write
+ the files to the current directory and let them burn in hell
+ for ever. */
+ fn = xstrdup(filename);
+ }
+ else
+ {
+ /* Ask for a file and/or directory name. */
+ fprintf(stdout, _("Please enter a file to save %s to [%s]: "),
+ what, filename);
+ fflush(stdout);
+
+ if((fn = readline(stdin, NULL, NULL)) == NULL)
+ {
+ fprintf(stderr, _("Error while reading stdin: %s\n"), strerror(errno));
+ return NULL;
+ }
+
+ if(strlen(fn) == 0)
+ /* User just pressed enter. */
+ fn = xstrdup(filename);
+ }
+
+ if((strchr(fn, '/') == NULL) || (fn[0] != '/'))
+ {
+ /* The directory is a relative path or a filename. */
+ char *p;
+
+ directory = get_current_dir_name();
+ asprintf(&p, "%s/%s", directory, fn);
+ free(fn);
+ free(directory);
+ fn = p;
+ }
+
+ umask(0077); /* Disallow everything for group and other */
+
+ /* Open it first to keep the inode busy */
+ if((r = fopen(fn, mode)) == NULL)
+ {
+ fprintf(stderr, _("Error opening file `%s': %s\n"),
+ fn, strerror(errno));
+ free(fn);
+ return NULL;
+ }
+
+ /* Then check the file for nasty attacks */
+ if(!is_safe_path(fn)) /* Do not permit any directories that are
+ readable or writeable by other users. */
+ {
+ fprintf(stderr, _("The file `%s' (or any of the leading directories) has unsafe permissions.\n"
+ "I will not create or overwrite this file.\n"),
+ fn);
+ fclose(r);
+ free(fn);
+ return NULL;
+ }
+
+ free(fn);
+
+ return r;