-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);
-
- fn = readline(stdin, NULL, NULL);
-
- if(!fn)
- {
- fprintf(stderr, _("Error while reading stdin: %s\n"), strerror(errno));
- return NULL;
+bool change_config_file(meshlink_handle_t *mesh, const char *name, const char *key, const char *value) {
+ char filename[PATH_MAX];
+ char tmpname[PATH_MAX];
+ char buf[MAX_STRING_SIZE];
+ const int keylen = strlen(key);
+
+ snprintf(filename, PATH_MAX, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
+ snprintf(tmpname, PATH_MAX, "%s.tmp", filename);
+
+ FILE *in = fopen(filename, "r");
+ if(!in) {
+ // Hm, maybe the file does not exist? Try appending.
+ return append_config_file(mesh, name, key, value);
+ }
+
+ FILE *out = fopen(tmpname, "w");
+ if(!out) {
+ logger(mesh, MESHLINK_ERROR, "Failed to write `%s': %s", tmpname, strerror(errno));
+ fclose(in);
+ return false;
+ }
+
+ bool ignore = false;
+
+ while(readline(in, buf, sizeof buf)) {
+ if(ignore) {
+ if(!strncmp(buf, "-----END", 8))
+ ignore = false;
+ } else {
+ if(!strncmp(buf, "-----BEGIN", 10))
+ ignore = true;
+ }
+
+ if(!ignore && !strncmp(buf, key, keylen)) {
+ if(strchr("\t =", buf[keylen])) {
+ continue;
+ }
+ }
+
+ fputs(buf, out);
+ fputc('\n', out);
+ }
+
+ if(ferror(in)) {
+ logger(mesh, MESHLINK_ERROR, "Failed to read `%s': %s", filename, strerror(errno));
+ fclose(in);
+ fclose(out);
+ return false;
+ }
+
+ fclose(in);
+
+ fprintf(out, "%s = %s\n", key, value);
+
+ if(ferror(out)) {
+ logger(mesh, MESHLINK_ERROR, "Failed to write `%s': %s", tmpname, strerror(errno));
+ fclose(out);
+ return false;
+ }
+
+ fclose(out);
+
+#ifdef HAVE_MINGW
+ // We cannot atomically replace files on Windows.
+ char bakname[PATH_MAX];
+ snprintf(bakname, PATH_MAX, "%s.bak", filename);
+ if(rename(tmpname, bakfile) || rename(bakfile, filename)) {
+ rename(bakfile, filename);
+#else
+ if(rename(tmpname, filename)) {
+#endif
+ logger(mesh, MESHLINK_ERROR, "Failed to update `%s': %s", filename, strerror(errno));
+ return false;