Function configfile_replace_var

lightningd/configs.c:411–463

This comments out the config file entry or maybe replace one */

/* This comments out the config file entry or maybe replace one */
static void configfile_replace_var(struct lightningd *ld,
				   const struct configvar *cv,
				   const char *replace)
{
	char **lines, *template, *contents;
	const char *err;
	int outfd;

	switch (cv->src) {
	case CONFIGVAR_CMDLINE:
	case CONFIGVAR_CMDLINE_SHORT:
	case CONFIGVAR_PLUGIN_START:
	case CONFIGVAR_SETCONFIG_TRANSIENT:
		/* These can't be commented out */
		abort();
	case CONFIGVAR_EXPLICIT_CONF:
	case CONFIGVAR_BASE_CONF:
	case CONFIGVAR_NETWORK_CONF:
		break;
	}

	/* If it changed *now*, that's fatal: we already set it locally! */
	err = grab_and_check(tmpctx, cv->file, cv->linenum, cv->configline,
			     &lines);
	if (err)
		fatal("%s", err);

	if (replace)
		lines[cv->linenum - 1] = cast_const(char *, replace);
	else
		lines[cv->linenum - 1] = tal_fmt(lines, "# setconfig commented out (see config.setconfig): %s",
						 lines[cv->linenum - 1]);

	log_info(ld->log, "setconfig: %s line %u of %s (%s)",
		 replace ? "replaced" : "commented out",
		 cv->linenum, cv->file, cv->configline);

	template = tal_fmt(tmpctx, "%s.setconfig.XXXXXX", cv->file);
	outfd = mkstemp(template);
	if (outfd < 0)
		fatal("Creating %s: %s", template, strerror(errno));

	contents = tal_strjoin(tmpctx, take(lines), "\n", STR_TRAIL);
	if (!write_all(outfd, contents, strlen(contents)))
		fatal("Writing %s: %s", template, strerror(errno));
	if (fsync(outfd) != 0)
		fatal("Syncing %s: %s", template, strerror(errno));

	if (rename(template, cv->file) != 0)
		fatal("Renaming %s over %s: %s",
		      template, cv->file, strerror(errno));
	close(outfd);
}

static const char *base_conf_file(const tal_t *ctx,
				  struct lightningd *ld,