我有一些非常基本的gpxlogger代码，可以很好地将所有数据写入文件。 （下同）
gpxlogger -d -f /home/pi/Desktop/EPQ/temp_gps/gpslog
但是我希望这段代码始终写入同一个文件而不会覆盖它。因此，如果可能的话，当它开始记录时，它将转到文件的底部并开始在那里记录数据，低于已记录的数据。
谢谢， 丹。
Javascript读取xml文件
<script src="http://maps.google.com/maps?file=api&v=2&key=ABQIAAAA7_kD1t_m22HBF9feCaDPZxQwcATY4FXmxYwkk9LNWGtAQdNKTBS1kBsTEqrRPg2kWxuNdmf2JVCIkQ" type="text/javascript"></script>
<script src="http://gmaps-utility-library.googlecode.com/svn/trunk/markermanager/release/src/markermanager.js"> </script><script>
var map;
function initialize () {
if (GBrowserIsCompatible()) {
map = new GMap2(document.getElementById("map_canvas"));
map.setCenter(new GLatLng(53.423027, -1.523462), 10);
map.addControl(new GLargeMapControl());
map.addControl(new GMapTypeControl());
map.addMapType(G_PHYSICAL_MAP);
map.setMapType(G_PHYSICAL_MAP);
addMarkersFromXML();
}
}
function addMarkersFromXML(){
var batch = [];
mgr = new MarkerManager(map);
var request = GXmlHttp.create();
request.open('GET', 'gpslog.xml', true);
request.onreadystatechange = function() {
if (request.readyState == 4 && request.status == 200) {
var xmlDoc = request.responseXML;
var xmlrows = xmlDoc.documentElement.getElementsByTagName("trkpt");
for (var i = 0; i < xmlrows.length; i++) {
var xmlrow = xmlrows[i];
var xmlcellLatitude = parseFloat(xmlrows[i].getAttribute("lat"));
var xmlcellLongitude = parseFloat(xmlrows[i].getAttribute("lon"));
var point = new GLatLng(xmlcellLatitude,xmlcellLongitude);
//get the time of the pin plot
var xmlcellplottime = xmlrow.getElementsByTagName("time")[0];
var celltextplottime = xmlcellplottime.firstChild.data;
//get the elevation of the pin plot
var xmlcellplotelevation = xmlrow.getElementsByTagName("ele")[0];
var celltextplotelevation = xmlcellplotelevation.firstChild.data;
//get the number of satellites at the time of the pin plot
var xmlcellplotsat = xmlrow.getElementsByTagName("sat")[0];
var celltextplotsat = xmlcellplotsat.firstChild.data;
var htmlString = "Time: " + celltextplottime + "<br>" + "Elevation: " + celltextplotelevation + "<br>" + "Satellites: " + celltextplotsat;
//var htmlString = 'yes'
var marker = createMarker(point,htmlString);
batch.push(marker);
}
mgr.addMarkers(batch,10);
mgr.refresh();
}
}
request.send(null);
}
function createMarker(point,html) {
var marker = new GMarker(point);
GEvent.addListener(marker, "click", function() {
marker.openInfoWindowHtml(html);
});
return marker;
}
</script>
</head>
<body onload="initialize()" onunload="GUnload()">
<div id="map_canvas" style="width: 1350px; height: 800px"></div>
<div id="message"></div>
</body>
</html>
答案 0 :(得分：0)
您遇到了一个守护进程的gpxlogger问题，该文件名需要-f标志，并且会覆盖该文件。你知道吗。
我看到有两种选择。 不作为守护程序运行gpxlogger
gpxlogger >> /home/pi/Desktop/EPQ/temp_gps/gpslog
或将其作为守护程序运行，并将cat文件作为可附加文件运行
gpxlogger -d -f /home/pi/Desktop/EPQ/temp_gps/gpslog & cat /home/pi/Desktop/EPQ/temp_gps/gpslog >> /home/pi/Desktop/EPQ/temp_gps/gpslog_concatenated
答案 1 :(得分：0)
另一种查看它的方法是创建顺序日志，然后将它们与gpsbable连接起来，但为了做到这一点，你需要有一个脚本和一个索引。
制作索引echo 0 > ~/.gpxfilecount
打开收藏的编辑器并创建一个包含以下内容的文件：
#! /usr/bin/bash
COUNT=`cat ~/.gpxfilecount`
echo $(($COUNT + 1 )) > ~/.gpxfilecount
filename="gpxlogfile${COUNT}.gpx"
exec gpxlogger -d -f $filename
标记脚本可执行文件chmod +x ~/bin/gpxer.sh（或收藏夹名称）。
每次启动gpxlogger时，都会创建一个递增的文件名。然后可以通过gpsbable gpsbabel -i geo -f gpxlogfile1.gpx -f gpxlogfile2.gpx -f gpxlogfile3.gpx -o gpx -F biglogcat.gpx将这些文件连接起来而不会流泪......或者gpsbable可以工作。
答案 2 :(得分：0)
这是另一种选择。
查看gps3.py，将其和以下脚本放入目录。
它从gpsd读取数据;如果gpx日志文件不存在，则创建它;追加＆＃34; trackpoint＆＃34;数据存在时的数据;同时保持相同的文件并附加＆＃34; trackpoint＆＃34;重启后的数据。
将两者放在同一目录中，然后让你javascript读取文件。或者将整个结构放在同一个脚本中。
#!/usr/bin/env python
# coding=utf-8
""" gpx logger to create and append a gpx formatted log of gpsd data """
import os
import time
import gps3
from datetime import datetime
the_connection = gps3.GPSDSocket()
the_fix = gps3.Fix()
the_log = '/tmp/gpx3.gpx'
creation = datetime.utcnow()
fmt = '%Y-%m-%d %H:%M:%S %Z%z'
genesis = creation.strftime(fmt)
if not os.path.isfile(the_log):
header = ('<?xml version = "1.0" encoding = "utf-8"?>\n'
'<gpx version = "1.1" '
'creator = "GPSD 3.9 - http://catb.org/gpsd" '
'client = "gps3.py - http://github.com/wadda/gps3"'
'xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"'
'xmlns = "http://www.topografix.com/GPX/1/1"'
'xsi:schemaLocation = "http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">\n '
'<metadata>\n '
' <time>{}\n'
'</metadata>\n').format(genesis)
f = open(the_log, 'w')
f.write(header)
f.close()
try:
for new_data in the_connection:
if new_data:
the_fix.refresh(new_data)
if not isinstance(the_fix.TPV['lat'], str): # lat determinate of when data is 'valid'
latitude = the_fix.TPV['lat']
longitude = the_fix.TPV['lon']
altitude = the_fix.TPV['alt']
time = the_fix.TPV['time']
mode = the_fix.TPV['mode']
tag = the_fix.TPV['tag']
sats = the_fix.satellites_used()
hdop = the_fix.SKY['hdop']
vdop = the_fix.SKY['vdop']
pdop = the_fix.SKY['pdop']
trackpoint = ('<trkpt lat = {} lon = {}>\n'
' <ele>{}</ele>\n'
' <time>{}</time>\n'
' <src>GPSD tag ="{}"</src>\n'
' <fix>{}</fix >\n'
' <sat>{}</sat>\n'
' <hdop>{}</hdop>\n'
' <vdop>{}</vdop>\n'
' <pdop>{}</pdop>\n'
'</trkpt>\n').format(latitude, longitude, altitude, time, tag, mode, sats[1], hdop, vdop, pdop)
addendum = open(the_log, 'a')
addendum.write(trackpoint)
addendum.close()
except Exception as error:
print('Danger-Danger',error)
答案 3 :(得分：0)
我很好奇从头开始构建gpx文件看起来只使用minidom。不幸的是生活干预了，抱歉延迟......
当这个脚本（下面）gpex3.py仍然有点粗糙和低效（每秒读/写）时，它与gps3.py放在同一个目录中，它会创建一个可附加的gpx档案/tmp/gpx3.gpx
#! /usr/bin/python3
# coding=utf-8
"""banana"""
import xml.dom.minidom
import gps3
import time
from datetime import datetime, timezone, timedelta
import os
import sys
gps_connection = gps3.GPSDSocket()
gps_fix = gps3.Fix()
the_log = '/tmp/gpx3.gpx'
def start_time():
"""time in the beginning"""
timestart = str(datetime.utcnow().replace(tzinfo=(timezone(timedelta(0)))))
return timestart
def close(doc):
"""write file to disk and close"""
log_write = open(the_log, "w")
doc.writexml(log_write)
log_write.close()
if os.path.isfile(the_log):
doc = xml.dom.minidom.parse(the_log) # opens the pre-existing
gpx_element = doc.firstChild
else:
doc = xml.dom.minidom.Document()
gpx_element = doc.createElement("gpx")
doc.appendChild(gpx_element)
trk_element = doc.createElement("trkseg")
trk_element.setAttribute("began", start_time())
gpx_element.appendChild(trk_element)
utc = alt = hdop = vdop = pdop = mode = sats = tag = 'n/a'
try:
tpv_list = {'time': utc, 'ele': alt, 'tag': tag}
sky_list = {'hdop': hdop, 'vdop': vdop, 'pdop': pdop}
# misc_list = {'sat': sats, 'fix':mode} # just an account
element = {}
x = 1 # for the 'is it working?'
for new_data in gps_connection:
if new_data:
gps_fix.refresh(new_data)
if not isinstance(gps_fix.TPV['lat'], str):
trkpt_element = doc.createElement("trkpt")
trk_element.appendChild(trkpt_element)
trkpt_element.setAttribute('lat', str(gps_fix.TPV['lat']))
trkpt_element.setAttribute('lon', str(gps_fix.TPV['lon']))
# tpv_list[key]
for key in tpv_list:
if key == 'ele':
element[key] = '{}'.format(gps_fix.TPV['alt']) # because consistency with labels is a horrible.
else:
element[key] = '{}'.format(gps_fix.TPV[key])
# sky_list[key]
for key in sky_list:
element[key] = '{}'.format(gps_fix.SKY[key])
# Misc.
element['sat'] = '{}'.format(gps_fix.satellites_used()[1])
element['fix'] = '{}'.format(("ZERO", "NO_FIX", "2D", "3D")[gps_fix.TPV['mode']])
for key in element:
trkpt_data = doc.createElement(key)
trkpt_element.appendChild(trkpt_data)
new_value = doc.createTextNode(element[key])
trkpt_data.appendChild(new_value)
# print(doc.toprettyxml())
close(doc) # write to file with every trackpoint
print('Cycle', x) # Only an "is it working?"
x += 1
time.sleep(1)
except KeyboardInterrupt:
gps_connection.close()
print("\nTerminated by user\nGood Bye.\n")
if __name__ == '__main__':
pass