view rvinterf/etmsync/fsnew.c @ 407:19e5a3e2f9c0

fcup-settime: moved time() retrieval a little closer to the output A fundamental problem with all simple time transfer tools is that there is always some delay between the time retrieval on the source system and that transmitted time being set on the destination, and the resulting time on the destination system is off by that delay amount. This delay cannot be fully eliminated when working in a simple environment like ours, but we should make our best effort to minimize it. In the present case, moving the atinterf_init() call before the time() retrieval should make a teensy-tiny improvement.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 11 Aug 2018 21:52:17 +0000
parents 0cb766828d7a
children 003e48f8ebe1
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/*
 * In this module we are going to implement the commands that upload
 * new FreeCalypso-invented stuff into the FFS of our FC devices.
 */

#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "exitcodes.h"

char batterytab_compile_tool[] = "/opt/freecalypso/bin/compile-fc-batt";
char charging_compile_tool[]   = "/opt/freecalypso/bin/compile-fc-chg";

upload_fc_table_from_ascii(asciisrc, compiletool, ffs_pathname)
	char *asciisrc, *compiletool, *ffs_pathname;
{
	char tmpfile[] = "/tmp/fc-fsioXXXXXX";
	int tmpfd;
	pid_t child, waitres;
	int status, rc;

	tmpfd = mkstemp(tmpfile);
	if (tmpfd < 0) {
		fprintf(stderr, "unable to get temp file via mkstemp()\n");
		return(ERROR_UNIX);
	}
	close(tmpfd);
	child = vfork();
	if (child < 0) {
		fprintf(stderr, "unable to vfork to run compiler tool\n");
		unlink(tmpfile);
		return(ERROR_UNIX);
	}
	if (!child) {
		execl(compiletool, compiletool, asciisrc, tmpfile, 0);
		perror(compiletool);
		_exit(ERROR_UNIX);
	}
	waitres = waitpid(child, &status, 0);
	if (waitres != child || !WIFEXITED(status)) {
		fprintf(stderr, "unexpected wait result after compiler run\n");
		unlink(tmpfile);
		return(ERROR_UNIX);
	}
	rc = WEXITSTATUS(status);
	if (rc) {
		unlink(tmpfile);
		return rc;
	}
	rc = fwrite_from_file(ffs_pathname, tmpfile);
	unlink(tmpfile);
	return rc;
}

cmd_write_battery_table(argc, argv)
	char **argv;
{
	return upload_fc_table_from_ascii(argv[1], batterytab_compile_tool,
					  "/etc/batterytab");
}

cmd_write_charging_config(argc, argv)
	char **argv;
{
	return upload_fc_table_from_ascii(argv[1], charging_compile_tool,
					  "/etc/charging");
}