HitThat is it. So easy, just switching among buttons, to highlightkey, then hit to accept the license.
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-backports/Release.gpg Unable to connect to us.archive.ubuntu.com:http:
sudo rm /var/lib/apt/lists/* -vf sudo apt-get update
qyang@lubuntu-laptop:~$ service anacron start
qyang@lubuntu-laptop:~$ service anacron status
● anacron.service - Run anacron jobs
Loaded: loaded (/lib/systemd/system/anacron.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2015-11-21 09:19:57 AEDT; 4s ago
Main PID: 10233 (anacron)
CGroup: /system.slice/anacron.service
└─10233 /usr/sbin/anacron -dsq
Nov 21 09:19:57 lubuntu-laptop systemd[1]: Started Run anacron jobs.
Nov 21 09:19:57 lubuntu-laptop systemd[1]: Starting Run anacron jobs...
Nov 21 09:19:57 lubuntu-laptop anacron[10233]: Anacron 2.3 started on 2015-11-21
Nov 21 09:19:57 lubuntu-laptop anacron[10233]: Will run job `cron.daily' in 5 min.
Nov 21 09:19:57 lubuntu-laptop anacron[10233]: Will run job `svnsyncPQAFW.daily' in 15 min.
Nov 21 09:19:57 lubuntu-laptop anacron[10233]: Jobs will be executed sequentially
root@trac ~# cat /etc/crontab # /etc/crontab: system-wide crontab # Unlike any other crontab you don't have to run the `crontab' # command to install the new version when you edit this file # and files in /etc/cron.d. These files also have username fields, # that none of the other crontabs do. SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin # m h dom mon dow user command 17 * * * * root cd / && run-parts --report /etc/cron.hourly 25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily ) 47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly ) 52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly ) #25 6 * * * root test -x /usr/sbin/anacron || ( cd /root/AuctionResults && run-parts --report /root/AuctionResults) 00 12 * * 7 root test -x /usr/sbin/anacron || ( cd /root/AuctionResults && run-parts --report /root/AuctionResults) #Run any executable files,eg.runpython under nominated folder AuctionResults
root@trac ~# ls -al ~/AuctionResults total 852 drwxr-xr-x 2 root root 4096 Nov 15 12:00 . drwx------ 11 root root 4096 Sep 9 00:41 .. -rwxr-xr-x 1 root root 1105 Jul 14 13:48 file-retrieve-via-url.py -rwxr-xr-x 1 root root 39 Jun 9 22:43 runpython
qyang@lubuntu-laptop:~/Svn_Local_Personal/A_001_Notes$ locate cron |grep bin /usr/bin/crontab /usr/sbin/anacron /usr/sbin/cron
/etc/cron.daily/.placeholder /etc/cron.daily/0anacron /etc/cron.daily/apport /etc/cron.daily/apt /etc/cron.daily/bsdmainutils /etc/cron.daily/dpkg /etc/cron.daily/logrotate /etc/cron.daily/man-db /etc/cron.daily/mlocate /etc/cron.daily/ntp /etc/cron.daily/passwd /etc/cron.daily/popularity-contest /etc/cron.daily/update-notifier-common /etc/cron.hourly/.placeholder /etc/cron.monthly/.placeholder /etc/cron.monthly/0anacron /etc/cron.weekly/.placeholder /etc/cron.weekly/0anacron /etc/cron.weekly/fstrim /etc/cron.weekly/man-db /etc/cron.weekly/update-notifier-common /etc/default/anacron /etc/default/cron /etc/init/anacron.conf /etc/init/cron.conf /etc/init.d/anacron /etc/init.d/cron
R (sampling rate) = 100MS/s fs (signal being sampled = 70MHz fN (the Nyquist frequency) = 50MHz fa (aliased frequency) = 30MHz The frequency of the aliased signal can be found from the following simple equation: fa = |R*n - fs|Although sampling at twice the Nyquist frequency will ensure that you measure the correct frequency of your signal, it will not be sufficient to capture the shape of the waveform. If the shape of the waveform is desired, you should sample at a rate approximately 10 times the Nyquist theory.
If known input frequency range, then sample rate more than 2*InputFreqRange? will remove aliasing. However, real input signal could include signal frequency higher than wanted frequency range, these high frequency signal will cause aliasing at pre-designed smapling rate. (high freq signal and low freq signal end up with same sampling points at lower (than required) sampling rate.) That's the whole reason u need anti-aliasing filter in the front end to filter out unsupported high frequency signals.
#!/usr/bin/env python
import urllib
from datetime import datetime
saveFileName = "Sydney-Auction-Result-"+datetime.now().strftime("%Y%m%d%H%M%S")+".pdf"
urllib.urlretrieve ("http://domainmastheads.homepriceguide.com.au/saturday_auction_results/Sydney.pdf",saveFileName )
saveFileName = "Adelaide-Auction-Result-"+datetime.now().strftime("%Y%m%d%H%M%S")+".pdf"
urllib.urlretrieve ("http://domainmastheads.homepriceguide.com.au/saturday_auction_results/Adelaide.pdf",saveFileName )
saveFileName = "Melbourne-Auction-Result-"+datetime.now().strftime("%Y%m%d%H%M%S")+".pdf"
urllib.urlretrieve ("http://domainmastheads.homepriceguide.com.au/saturday_auction_results/Melbourne.pdf",saveFileName )
saveFileName = "Brisbane-Auction-Result-"+datetime.now().strftime("%Y%m%d%H%M%S")+".pdf"
urllib.urlretrieve ("http://domainmastheads.homepriceguide.com.au/saturday_auction_results/Brisbane.pdf",saveFileName )
#saveFileName = "Sydney-Domain-Auction-Result-"+datetime.now().strftime("%Y%m%d%H%M%S")+".pdf"
#urllib.urlretrieve ("http://www.domain.com.au/apm/saturday_auction_results/Sydney_Domain.pdf",saveFileName )
# Creat source folder and files and blank destination folder
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ mkdir src dst
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ mkdir src/a
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ echo "hell a" > src/a/file1.txt
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
└── src
└── a
└── file1.txt
# rsync to test folder and file synch. Both 'a' and 'file1' appeared under 'dst'.
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ └── a
│ └── file1.txt
└── src
└── a
└── file1.txt
# Test newly added folder 'b' being synched
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ mkdir src/b
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ ├── a
│ │ └── file1.txt
│ └── b
└── src
├── a
│ └── file1.txt
└── b
# Test newly added file 'file2.txt' being synched
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ echo "hell b" > src/b/file2.txt
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ ├── a
│ │ └── file1.txt
│ └── b
│ └── file2.txt
└── src
├── a
│ └── file1.txt
└── b
└── file2.txt
# Test newly delete folder 'a' and 'file1.txt' inside being synched.
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rm -rf src/a/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ └── b
│ └── file2.txt
└── src
└── b
└── file2.txt
# Test newly delete file 'file2.txt' being synched.
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rm src/b/file2.txt
rm: remove regular file ‘src/b/file2.txt’? y
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ └── b
└── src
└── b
# Add back 'file2.txt' and check
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ echo "hell b" > src/b/file2.txt
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ └── b
│ └── file2.txt
└── src
└── b
└── file2.txt
# modify 'file2.txt' and check synch
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ cat dst/b/file2.txt
hell b
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ vi src/b/file2.txt
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ cat src/b/file2.txt
Modified ...hello b
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ rsync --delete --checksum --recursive src/ dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ cat dst/b/file2.txt
Modified ...hello b
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ └── b
│ └── file2.txt
└── src
└── b
└── file2.txt
Using cp command line for multiple files copy
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ └── b
│ └── file2.txt
└── src
├── a
│ └── file1.txt
└── b
├── file2.txt
└── file3.txt
5 directories, 4 files
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ cp {src/a/file1.txt,src/b/file{2..3}.txt} dst/
qyang@lubuntu-laptop:~/Trash/Sandbox-Trial$ tree
.
├── dst
│ ├── b
│ │ └── file2.txt
│ ├── file1.txt
│ ├── file2.txt
│ └── file3.txt
└── src
├── a
│ └── file1.txt
└── b
├── file2.txt
└── file3.txt
#!/bin/bash pushd ~/Svn_Local_Proj/Cascade/Firmware/ svn up # Synch two local SVN copies,but ingore .svn etc. rsync --delete --cvs-exclude --checksum --recursive ~/Svn_Local_Proj/Cascade/Firmware/ ~/Svn_Local_Proj_HomeTrac/Proj_FW/ pushd ~/Svn_Local_Proj_HomeTrac/Proj_FW/ svn up #Add new files to repo if there are new files svn add --force * --auto-props --parents --depth infinity svn ci -m"Auto Synch SVN copy to Trac from Lubuntu" popd popd
#!/bin/bash # Copy from AWS # Password based ssh access, but downside is disclose plain text password. Better use ssh key pair based access # sshpass -p "Password" scp -pv root@qqec2.tklapp.com:~/AuctionResults/*.pdf ./ rsync --checksum qqec2:~/AuctionResults/*.pdf ./ echo "Done synch with AWS" ssh qqec2 "if [ ! -d 'AuctionResults-Bkup' ]; then mkdir -v AuctionResults-Bkup; echo 'Created folders that doesnot exist';fi; #ssh qqec2 "if [ ! -d "AuctionResults-Bkup" ]; " #"then mkdir -v AuctionResults-Bkup; " #"echo "Created folders that doesnot exist";" #"fi;" #"cp -vp AuctionResults/*.pdf AuctionResults-Bkup/"" echo "Done moving all download pdf files to bkup folder on AWS"
explorer . # For windows command line nautilus . # Linux command line open . # MAC OS X dolphin . # Linux KDE 4
qyang@lubuntu-laptop:~$ dpkg --list |grep manpage ii manpages 3.74-1ubuntu1 all Manual pages about using a GNU/Linux system ii manpages-dev 3.74-1ubuntu1 all Manual pages about using GNU/Linux for development ii manpages-posix 2.16-1 all Manual pages about using POSIX system ii manpages-posix-dev 2.16-1 all Manual pages about using a POSIX system for development
#apt-get install manpages-posix manpages-posix-dev #yum install man-pages #yum install libstdc++-docs to see man page of C++ library
$man pthreads $man ldd $man pthread_mutex_lock $man std::iostream $man std::vector $man malloc
[q.yang@fedora20 Trash]$ gcc testsomain.c -o testsomain -L./ -ltestso
[q.yang@fedora20 Trash]$ gcc testsomain.c testso.c -o testsomain
#include#include "testso.h" int main(void) { printf("Testing calling function in *.so \n"); Ext_PrintHello(); }
#includevoid Ext_PrintHello(void) { printf("%s Invoked from external module.\n",__func__); }
//#error "this file has been included here" void Ext_PrintHello(void);
[q.yang@fedora20 Trash]$ gcc -shared -fPIC -o libtestso.so testso.c
[q.yang@fedora20 Trash]$ gcc testsomain.c -o testsomain -L./ -ltestso
[q.yang@fedora20 Trash]$ LD_LIBRARY_PATH=./ [q.yang@fedora20 Trash]$ export LD_LIBRARY_PATH
[q.yang@fedora20 Trash]$ ./testsomain Testing calling function in *.so Ext_PrintHello Invoked from external module.
duser@10.1.1.8:~/Trash$ file libtestso.so libtestso.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, BuildID[sha1]=0xf54c8aad49c8dfd0220885eab40fe703c0e5495b, not stripped duser@10.1.1.8:~/Trash$ ldd libtestso.so libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb754b000) /lib/ld-linux.so.2 (0xb770f000)
duser@10.1.1.8:~/Trash$ld -L./ -ltestso --verbose .................. .................. ================================================== attempt to open /usr/i686-linux-gnu/lib32/libtestso.so failed attempt to open /usr/i686-linux-gnu/lib32/libtestso.a failed attempt to open /usr/local/lib32/libtestso.so failed attempt to open /usr/local/lib32/libtestso.a failed attempt to open /lib32/libtestso.so failed attempt to open /lib32/libtestso.a failed attempt to open /usr/lib32/libtestso.so failed attempt to open /usr/lib32/libtestso.a failed attempt to open /usr/local/lib/i386-linux-gnu/libtestso.so failed attempt to open /usr/local/lib/i386-linux-gnu/libtestso.a failed attempt to open /usr/local/lib/libtestso.so failed attempt to open /usr/local/lib/libtestso.a failed attempt to open /lib/i386-linux-gnu/libtestso.so failed attempt to open /lib/i386-linux-gnu/libtestso.a failed attempt to open /lib/libtestso.so failed attempt to open /lib/libtestso.a failed attempt to open /usr/lib/i386-linux-gnu/libtestso.so failed attempt to open /usr/lib/i386-linux-gnu/libtestso.a failed attempt to open /usr/lib/libtestso.so failed attempt to open /usr/lib/libtestso.a failed /usr/bin/ld.bfd.real: cannot find -ltestso
duser@10.1.1.8:~/Trash$ ld -L./ -ltestso --verbose .................... .................... ================================================== attempt to open .//libtestso.so succeeded -ltestso (.//libtestso.so) libc.so.6 needed by .//libtestso.so found libc.so.6 at /lib/i386-linux-gnu/libc.so.6 ld-linux.so.2 needed by /lib/i386-linux-gnu/libc.so.6 found ld-linux.so.2 at /lib/i386-linux-gnu/ld-linux.so.2 /usr/bin/ld.bfd.real: warning: cannot find entry symbol _start; not setting start address
public class MyCounter
{
private int count = 0; // count starts at zero
public synchronized void setCount(int amount)
{
count = amount;
}
public synchronized int getCount()
{
return count;
}
}
#include <iostream> #include <cstring> #include <vector> using namespace std; namespace DemoFunPt { typedef void (*CallBackFunc)(int i_input); // Register callback function vector<CallBackFunc> Callbackfuncs; void Func_A(int i_input) { cout<< "Hello from Func_A " << i_input << endl; } void Func_B(int i_input) { cout<< "Hello from Func_B " << i_input << endl; } void RegisterCallbackFunc(CallBackFunc i_FuncPt) { Callbackfuncs.push_back(i_FuncPt); } } int main() { DemoFunPt::RegisterCallbackFunc(DemoFunPt::Func_A); DemoFunPt::RegisterCallbackFunc(DemoFunPt::Func_B); for(int i=0; i< DemoFunPt::Callbackfuncs.size(); i++){ DemoFunPt::Callbackfuncs[i](i); } cout<<"Done demo" << endl; return 0; }
root@trac ~# g++ funcpointer.cpp -o test root@trac ~# ./test Hello from Func_A 0 Hello from Func_B 1 Done demo
./CreatAutoStartShell.py vncserverstart /home/qyang/startvncserver.sh ./CreatAutoStartShell.py startxcompmgr /home/qyang/startxcompmgr.shstartvncserver.sh
#!/bin/bash vncserver &startxcompmgr.sh
#!/bin/bash xcompmgr -n &CreatAutoStartShell.py
#!/usr/bin/env python3 import os import sys home = os.environ["HOME"] name = sys.argv[1]; command = sys.argv[2] launcher = ["[Desktop Entry]", "Name=", "Exec=", "Type=Application", "X-GNOME-Autostart-enabled=true"] dr = home+"/.config/autostart/" if not os.path.exists(dr): os.makedirs(dr) file = dr+name.lower()+".desktop" if not os.path.exists(file): with open(file, "wt") as out: for l in launcher: l = l+name if l == "Name=" else l l = l+command if l == "Exec=" else l out.write(l+"\n") else: print("file exists, choose another name")
#!/usr/bin/env python import matplotlib.pyplot as plt import datetime ax = tuple([datetime.datetime(2015, 10, 27, 17, 17, sec) for sec in range(1,10)]) print ax ay = tuple(range(1,10)) plt.plot(ax,ay) # Beautify the display format plt.gcf().autofmt_xdate() plt.show()When doing enough zoom in, it will display in macro seconds resolution. When zooming out enough,it will display dates.
#include <stdio.h>
#define TEST_3
void FuncA ()
{
#ifdef TEST_0
// 0 value initialization only happen once if defined 'static'.
static int StaticVar=0;
#endif
#ifdef TEST_1
// 0 value initialization happen every time when FuncA is called.
int StaticVar=0;
#endif
#ifdef TEST_2
// When not give inital value, system set StaticVar to '0'
// Changed value will stay next time when FuncA is called as StaticVar
// is defined with keyward 'static'.
static int StaticVar;
printf("StaticVar is : %d\n",StaticVar);
StaticVar = 2;
#endif
#ifdef TEST_3
// When no 'static', system set StaticVar to a random value.
// (I think it depends on what value in stack.)
// But in test it seems, StaticVar keep same value as it's retrieving
// value from same postion in stack.
int StaticVar;
printf("StaticVar is : %d\n",StaticVar);
StaticVar = 3;
#endif
printf("StaticVar is : %d\n",StaticVar);
StaticVar++;
}
void main()
{
FuncA();
FuncA();
FuncA();
FuncA();
FuncA();
FuncA();
printf ("====Done====\n");
}
The results after defining different test cases:qyang@lubuntu-laptop:~$ ./Learn_static StaticVar is : 0 StaticVar is : 1 StaticVar is : 2 StaticVar is : 3 StaticVar is : 4 StaticVar is : 5 ====Done====Test_1
qyang@lubuntu-laptop:~$ ./Learn_static StaticVar is : 0 StaticVar is : 0 StaticVar is : 0 StaticVar is : 0 StaticVar is : 0 StaticVar is : 0 ====Done====Test_2
qyang@lubuntu-laptop:~$ ./Learn_static StaticVar is : 0 StaticVar is : 2 StaticVar is : 3 StaticVar is : 2 StaticVar is : 3 StaticVar is : 2 StaticVar is : 3 StaticVar is : 2 StaticVar is : 3 StaticVar is : 2 StaticVar is : 3 StaticVar is : 2 ====Done====Test_3
qyang@lubuntu-laptop:~$ ./Learn_static StaticVar is : 134513947 StaticVar is : 3 StaticVar is : 4 StaticVar is : 3 StaticVar is : 4 StaticVar is : 3 StaticVar is : 4 StaticVar is : 3 StaticVar is : 4 StaticVar is : 3 StaticVar is : 4 StaticVar is : 3 ====Done====
When you have a pointer to an object, the object may actually be of a class that is derived from the class of the pointer (e.g., a Vehicle* that is actually pointing to a Car object; this is called “polymorphism”多态性). Dynamic binding is a result of virtual functions.
cp {*.doc,*.pdf} ~
This will copy anything ending with .doc or .pdf to the users home directory. Note that spaces are not allowed after the commas (or anywhere else).find -regex ".*\.\(xls\|csv\)"find -name "*.xls" -o -name "*.csv"
In [33]: 10*math.log(10,10) Out[33]: 10.0 In [34]: 10*math.log(2,10) 2 times Out[34]: 3.0102999566398116 how 3 dB derived
git fetch --dry-run
Useful Tips Section
Visit the Useful Tips Section Visit the Useful Tips Section
The tag defines a hyperlink, which is used to link from one page to another. In HTML 4.01, the tag could be either a hyperlink or an anchor. In HTML5, the tag is always a hyperlink, but if it has no href attribute, it is only a placeholder for a hyperlink. HTML5 has some new attributes, and some HTML 4.01 attributes are no longer supported.
#!/bin/sh xrdb $HOME/.Xresources xsetroot -solid grey -cursor_name left_ptr autocutsel -fork lxsession -s Lubuntu -e LXDE
GNOME Keyring is a collection of components in GNOME that store secrets, passwords, keys, certificates and make them available to applications.
GNOME Keyring is integrated with the user's login, so that their secret storage can be unlocked when the user logins into their session.
GNOME Keyring is based around a standard called PKCS#11, which is a standard way for applications to manage certificates and keys on smart cards or secure storage.
[globals] bitmap_cache=yes bitmap_compression=yes port=3389 crypt_level=low channel_code=1 # set empty username because VNC auth # doesn't actually use username, so no # point in asking the user for one. [xrdp1] name=Active Local Login lib=libvnc.so username= password=ask ip=127.0.0.1 port=5900 [xrdp2] name=Clean Session lib=libvnc.so username= password=ask ip=127.0.0.1
port=5901
$sudo vino-preferences
