Mika/Notes/Computer Stuff: Difference between revisions

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(→‎Command line: dish space to disk space)
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* rsync -rP: synches data with the options recursive and partial.
* rsync -rP: synches data with the options recursive and partial.
* ssh-keygen -p: lets me change the ssh password.
* ssh-keygen -p: lets me change the ssh password.
* df -h sizes for dish space  
* df -h sizes for disk space  
* du -h sizes for all folders
* du -h sizes for all folders

Revision as of 18:54, 24 February 2011

Miscellaneous

Writing down things I've learned. Some miscellaneous stuff are:

  • AJAX example: Checks if the username you entered is taken.
  • Javascript example: Drag choices up and down.
  • The tool to take a screen-videoshot (screencast) is to install recordmydesktop.
  • i686 (or i386) are 32 bit. Intel 64 bit processor is usually marked by _64 (really?)
  • Add a keyword (i.e. g) to a bookmark (i.e. http://www.google.com/search?q=%s) to make a shortcut in the address bar in Firfox.
  • R tutorial
  • Vector graphics vs Raster graphics
  • To rid the high pitch noise on my X61s, add options processor max_cstate=2 to your /etc/modprobe.d/options file.
  • In order to have certain things started every time I start my laptop, I can add things to the .Xsession file and start the session with Xsession when I log in. I've added things like gnome-power-management and awesome (awesome should be at the end).
  • I installed chromium by following this instruction.
  • Change network manager keyring by Applications > Accessories > Passwords and Encryption Keys.
  • Firefox forgets history after 7 days even though it's set to remember for up to 90 days. I went about:config and changed browser.history_expire_days to 90 days.
  • Converting 3gp to avi: I had to do sudo apt-get install ffmpeg libavcodec-extra-52 to get extra libraries. Then, a variation of ffmpeg -i input.3gp -f avi -vcodec xvid -acodec mp3 -ar 22050 output.avi because it gave errors for xvid (change to libxvid) and mp3 (change to libmp3lame). Still not working but it at least makes the output file.
  • Things to check out: gcommons, bak, acabed
  • In order to hide oversized background on a website, use in CSS: overflow:hidden;
  • sh files --> sh file.sh
  • imap folder can be merged by tagging all msgs in one folder and ;s (save) in the folder of my choice.
  • tgz files: gzip -d filename
  • baobao: graphical tool for space analysis
  • ibus-daemon wasn't working. I couldn't start it by ctrl-space: 1) ps ax |grep ibus (this showed "defunct for ibus) 2) ps ax |grep X 3) restart X by killing

the process (That didn't fix it. See the next point.)

  • upon Ubuntu Upgrade, the Japanese input stopped working ("no input window" in ibus). I uninstalled scim and it's all fixed now.
  • smbclient -L (server name) to see the list of services on the server.

Debian

  • Look at packages.qa.debian for todo's and qa.debian under my name for all the bugs and other information.
  • Popcon means popularity contest but there are people who install a package but don't use popcon.

Inkscape

  • I wanted to use a landscape canvas: Go to File -> Document Property - Choose Landscape.
  • I wanted to use text: Press F8.

Bug Report

  • I have trouble using Inkscape because it crashes when I try to use text. Here's how to get a backtrace:

gdb <path to inkscape executable>

(gdb) run [parameters (optional)]
# Carry out the actions to make the program crash
(gdb) bt

R

  • expression and assignment

PHP

Problem:

Again, I was doing this tutorial. I got the update/delete working but not insert. Even when I typed in the values, it returned Missing Values.

Solution

I said name="id" in select3.php in the form part for insert3.php but I said _POST[ID] in insert3.php. I changed it to id and it works fine now.


Problem:

I was doing this tutorial. First of all, I didn't quite write down the codes right:

  • incorrect update/delete versions linked from select.php
  • <?= is good <? = is not good
  • _GET['X'] is good but _GET["X"] is not good.
  • Don't free memory in the php that is required_once

After fixing all these, I got:

"failed query" SQL:SELECT Name WHERE ID =

Solution

Since I got the same message for both update and delete, I figured that the problem was elsewhere. I looked at select3 and after update3.php? I said id= instead ID= . I capitalized the id for bother update3 and delete3 and it works fine now.

MySQL

To be sorted:

Cheat Sheet

  • mysql_connect()
  • mysql_select_db()
  • mysql_query()
  • mysql_num_rows()
  • mysql_free_result()
  • mysql_close()
  • This is for outputting mysql queries into a text file: mysql > select * from table INTO OUTFILE '/tmp/test.txt';

Problem:

I tried to write a php and connect to mysql in it but I got an error:

Fatal Error: undefined function mysql_connect()

Solution:

This page suggested that mysql isn't enabled by dafault in php5. I installed php5-mysql and restarted apache2 (don't know if that was necessary) and now it works.


Problem:

I restarted my computer because I couldn't start gimp unless I was root. Clint told me that I should sudo /etc/init.d/dbus restart , which basically restarted my whole computer. Since then, I couldn't use mysql because I kept getting this error:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Solution:

I followed this and restarted mysql by:

/etc/init.d/mysql restart

But it fails. It seems like I touched my.cnf and didn't restart mysql, so when my computer restarted, it incorporated the changes I made in my.cnf and mysql stopped working. I reinstalled mysql-server through apt-get, restarted mysql and now it's fine.



Problem:

I have a bunch of text files from USDA, which contain bits and pieces USDA ASCII databases. I want to put them into mysql.

Solution:

1. I found schema.sql that Erik created, so I'm going to borrow it rather than creating my own.

mysql databasename < schema.sql -p


Problem:

mysql> create database newdatabase;

ERROR 1044 (42000): Access denied for user 'user'@'localhost'...

Solution:

mysql

1. Check grants for 'user'@'localhost' in mysql:

mysql> show grants for 'user'@'localhost';

2. Log into mysql as root (has all privileges) and change grants for a specific user:

mysql> grant all privileges on *.* to 'user'@'localhost';

Query OK, 0 rows affected (0.00 sec)

3. Log back into mysql as user (now has all privileges) and try creating a new database again.


Python

To be sorted

  • TypeError: fetchone() takes exactly 1 argument (2 given)
    • This really means 1 argument given because each method comes with an argument to begin with.
  • To obtain input, I can use raw_input().

Problem:

I wanted to create a wiki table from CIA's Infant Mortality Rate ranking data. I didn't want to change to the wiki table format, so I decided to write a python code.

Solutions:

I had to read a text file, make a list for each line, take out the words I need, and print in the wiki table format. I did the following first to change tabs to commas but that was probably not necessary:

    sed 's/\\t/,/g' Desktop/rawIMRdata.text > rawIMRdata2.text


When I forgot /g, it only outputted the last line.

Here's the python code:

    imr_data = open("rawIMRdata6.text")
    #f = file("imr_data","r")
    print {| class="wikitable" border="1" \n|- \n!  Ranking 1 \n!  Country 2 \n!  IMR \n
    for line in imr_data.readlines():
        # To make a list for each line from text file:
        a = line.split(',')
        #print a and strip the space after each word
        one = a[0].strip()
        two = a[1].strip()
        three = a[3].strip()	
        combined = '|-\n|' + one + '\n|' + two + '\n|' + three   
        print combined
    print r|}

Django


  • Tried setting up Django on my computer by following this tutorial

Problem:

It worked mostly ok but I couldn't go further than the second to the last coding box on page 4. I kept getting long error messages.

Solution:

Django tutorial about django.contrib.admin

1. Check if I typed in the correct codes.

2. Check if the output are the same everwhere:

Although the codes were correct, they didn't create all the necessary things, so it couldn't find the index.html.

  • I went to setting.py to specify:
    • the absolute path for Template_Dir. Don't forget the , after '/path/' .
    • two additional Installed_Apps: myprj_myapp (where I save my project) and django.contrib.admin . Run python manage.py syncdb afterwards.

This created myapp_post and django_admin_log in mysql database.


Javascript


JS Tutorial


HTML/CSS

Problem I couldn't put the content and the sidebar side by side.

Solution CSS: added floar:left to content.

Problem: I didn't know how to align text on both sides in html or css.

Solution: HTML: p style="text-align:justify CSS: p.special {text-align:justify;}

---

Problem:

I didn't know what meant.

Solution:

This website says: An HTML table has two kinds of cells:

   * Header cells - contains header information (created with the th element)
   * Standard cells - contains data (created with the td element)

Problem:

I didn't know what <form name="form1"> meant.

Solution:

"A form is an area that can contain form elements.

Form elements are elements that allow the user to enter information (like text fields, textarea fields, drop-down menus, radio buttons, checkboxes, etc.) in a form." とほほのjavascript

GPG/PGP

1. Make a gpg key. 2. Register on pool.sks-keyservers.net.

Command line

  • arch: get architecture info
  • uname -a: print system info
  • xev: finds information on the pressed keys
  • xmodmap -e "keycode ###=Multi_key": Enter the key number in ### to set the compose key.
  • import -windows root screenshot.png: Takes a screenshot of the entire screen instead of a window.
  • sudo acpi -V: tells me the temperature of my computer.
  • cat /etc/issue: gives the current version of Ubuntu
  • rsync -rP: synches data with the options recursive and partial.
  • ssh-keygen -p: lets me change the ssh password.
  • df -h sizes for disk space
  • du -h sizes for all folders