scp windows recursive copy problem

 In you encounter scp problem when doing a recursive copy from Windows to Linux, try adding the -O parameter.

scp -r -O sample-files/ target-server:/target-path/

Run X11 application in docker

 To run X11 / X-Window application in docker, the following tutorial provides a simple approach to archive it:

https://blog.yadutaf.fr/2017/09/10/running-a-graphical-app-in-a-docker-container-on-a-remote-server/

Stop QGIS from generating the .aux.xml files when opening GeoTiff files

1. Start QGIS
2. Go to "Settings" > "Options"
3. In Options window, find "System", then "Environment"
4. Add environment variable "GDAL_PAM_ENABLED" with value equals "NO"
5. Restart QGIS

Reference: https://blog.csdn.net/u014311125/article/details/108625203

Compile fanvanzh's 3dtiles in Linux

Working for fanvanzh's 3dtiles Linux compilation for days. Some items for reminding everybody how wants to do the same thing.

liwei0705 did a good move in making fanvanzh's 3dtiles converter works. But if you are using a new version of OSG and GDAL, pay attention to the following summarised reminders when building your own version of "_3dtile"

• Delete 3dtiles/bin, it is for windows only

• Compile your own OpenSceneGraph
• Copy OpenSceneGraph /lib to 3dtiles
• Copy OpenSceneGraph /include/* to 3dtiles/src/osg/*

• If not compile OpenSceneGraph on your own, you can install "openscenegraph" and "libopenscenegraph-dev" instead
• Delete /lib in 3dtiles (the /lib is for self-compiled OSG, GDAL actually)
• Delete 3dtiles/src/osg/ (no need to provide OSG header, use the one in libopenscenegraphi-dev)

• Install gdal-bin, libgdal-dev
• rm -rf 3dtiles/src/gdal (we will use libraries and header by gdal-bin and libgdal-dev)

• Source file: src/tileset.cpp
• Hide up #ifdef _WIN32, turn on "epsg_convert" and "wkt_convert"
• Comment out GDAL_DATA: 
• // CPLSetConfigOption("GDAL_DATA", path);

• For epsg_convert( )
• Don't use importFromEPSG(), use:
• // For 2326 Input (Hard code the input SRS) (Ref)
• inRs.importFromProj4("+proj=tmerc +lat_0=22.3121333333333 +lon_0=114.178555555556 +k=1 +x_0=836694.05 +y_0=819069.8 +ellps=intl +towgs84=-162.619,-276.959,-161.764,-0.067753,2.243648,1.158828,-1.094246 +units=m +no_defs +type=crs");
• // for 4326 Output (Hard code the output SRS) (Ref)
• outRs.importFromProj4("+proj=longlat +datum=WGS84 +no_defs +type=crs");

• Source file: src/earcut.hpp
• Add header files
• #include <stdexcept>
• #include <limits>

• Source file: build.rs
• In linux bulid config, add:
• println!("cargo:rustc-link-lib=gdal");

• When running the ./target/release/_3dtile
• export LD_LIBRARY_PATH=./lib

• Side notes, if you use "cargo run" for debugging and when to rebuild the project when some CPP files are modified, add the following in linux build config (build.rs): (reference)
• println!("cargo:rerun-if-changed=./src/tileset.cpp");

Setup autostart services in Linux with SELinux

1) Create your start / stop script in a predefined directory (e.g. /development/service-script/ )

• /development/service-script/start-cmd
• /development/service-script/stop-cmd

2) Allow SELinux to execute binaries in the predefined directory /development/service-script/ (!! important for SELinux)

    chcon -R -t bin_t /development/service-script/

3) Create abc.service in /etc/systemd/system/

    # Systemd unit file for ABC service

    [Unit] 
    Description=ABC service
    After=syslog.target network.target

    [Service]
    Type=forking

    ExecStart=/development/service-script/start-cmd
    ExecStop=/development/service-script/stop-cmd

    User=service_owner
    Group=service_owner
    UMask=0007
    RestartSec=10
    Restart=always

    [Install]
    WantedBy=multi-user.target

4) Reload systemd

    systemctl daemon-reload

5) Start ABC service

    systemctl start abc

6) If ABC service is working, then we can enabled it for autostart

    systemctl enable abc

NO_PUBKEY when updating QGIS in Linux / Ubuntu (2022)

Update the key file (qgis-archive.gpg) by:

wget  -qO  -  https://qgis.org/downloads/qgis-2022.gpg.key  |  gpg  --no-default-keyring  --keyring  gnupg-ring:/etc/apt/trusted.gpg.d/qgis-archive.gpg  --import

The NO_PUBKEY error message will be gone for 'apt update'

Separated dock for multiple workspace in Ubuntu

Separated dock for multiple workspace in Ubuntu, set the following to be true:

gsettings set org.gnome.shell.extensions.dash-to-dock isolate-workspaces true

Skip basic authentication headers before passing a request to proxypass target host

This can be done via "RequestHeader unset Authorization" 

<Location "/some_path">

    Require all granted

    ProxyPass https://target-host

    RequestHeader unset Authorization

</Location>

Reference: 1, 2

Ubuntu deactivate shift+numpad = number

 setxkbmap -option 'numpad:microsoft'

Reference: codegrepper.com 

Extract PDF content (from CHP) with Python

import re

import sys

import urllib.request

import pdfplumber

import pandas as pd

if (len(sys.argv) < 2):

    print("\n\nSyntax: python extract_pdf.py date_string (e.g. 20220124) \n\n")

    exit()

def main():    

    date_string  = sys.argv[1] # e.g. 20220124

    pdf_file_name = f"ctn_{date_string}.pdf" # PDF from CHP: https://www.chp.gov.hk/files/pdf/ctn_20220124.pdf

    #download_pdf( pdf_file_name )

    extract_pdf( pdf_file_name )

def extract_pdf( pdf_file_name ):

    with pdfplumber.open( f"./pdf/{pdf_file_name}" ) as pdf:

        for page in pdf.pages:

            #print(page)

            for table in page.extract_tables():

                df = pd.DataFrame(table[1:], columns=table[0])

                for index, row in df.iterrows():

                    if (isinstance(row[0], str) and len(row[0])>0):

                        rowid = row[0].replace(".","")

                        title = row[1].split("\n")

                        for i in range(0,len(title)):                            

                            if (re.search(u'[\u4e00-\u9fff]', title[i]) is None):

                                title[i] = ""

                        print(rowid, "".join(title))

def download_pdf ( pdf_file_name ) :

    pdfFile = urllib.request.urlopen(f"https://www.chp.gov.hk/files/pdf/{pdf_file_name}")

    file = open(f"./pdf/{pdf_file_name}", "wb")

    file.write(pdfFile.read())

    file.close()

main()