Category Archives: Ubuntu

SFTP Command to Transfer Files on Remote Servers

SSH File Transfer Protocol, a network protocol used for secure file transfer over secure shell.

SFTP (Secure File Transfer Protocol) runs over SSH protocol on standard port 22 by default to establish a secure connection. SFTP has been integrated into many GUI tools (FileZilla, WinSCP, FireFTP etc.).

Below are the most used commands for SFTP:

1. Connect to SFTP

To connect with SFTP we can use below commands.

[root@salayhin ~]# sftp salayhin@20.42.230.5

Connecting to 20.42.230.5...
tecmint@20.42.230.5's password:
sftp>

If we are using AWS we can add the pem file location with this command.

[root@salayhin ~]# sftp -i PemFile.pem salayhin@20.42.230.5

Continue reading SFTP Command to Transfer Files on Remote Servers

Python locale error: unsupported locale setting

Sometimes we are getting local error and cannot install packages via pip.

I found a solution to get rid of it.

Run this command from your command line interface.

$ export LC_ALL=C

Output from locale is:

$ locale
LANG=co404
LANGUAGE=
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_PAPER="C"
LC_NAME="C"
LC_ADDRESS="C"
LC_TELEPHONE="C"
LC_MEASUREMENT="C"
LC_IDENTIFICATION="C"
LC_ALL=C

Mysql ‘Got error -1 from storage engine’ error

Today I got an error while updating my mysql record . I got “Mysql ‘Got error -1 from storage engine’ error” every time I try to update.

Below are the logs I found from my mysql error logs:

MySQL Error log path: /var/log/mysql/error.log

InnoDB: A new raw disk partition was initialized or
InnoDB: innodb_force_recovery is on: we do not allow
InnoDB: database modifications by the user. Shut down
InnoDB: mysqld and edit my.cnf so that newraw is replaced
InnoDB: with raw, and innodb_force_... is removed.

Finally I got solution for that. To solve this issue follow below steps.

1. Stop your mysql server

 sudo service mysql stop 

2. Set innodb_force_recovery to 0 or remove this line from /etc/mysql/my.cnf

 innodb_force_recovery = 0 

3. Start your mysql server

 sudo service mysql start 

This will solve your problem.

Happy Coding 🙂

vi – basic commands

vi is a screen-oriented text editor originally created for the Unix operating system.

Basic commands:

To Start vi:

* vi filename Create or Edit filename starting at line 1
* vi -r filename Recover filename that was being edited 

To Exit vi:

* :x<return> Quit vi, writing out modified file to file named in original invocation
* :wq<return> Quit vi, writing out modified file to file named in original invocation
* :q<return> Quit or exit vi
* :q!<return> Quit vi even though latest changes have not 

Moving the cursor:

* j or <return> [or down-arrow] Move cursor down one line
* k[or up-arrow] Move cursor up one line
* h or<backspace> [or left-arrow]

Move cursor left one line:

* l or<space>[or right-arrow] Move cursor right one line
* 0(zero) Move cursor to start of current line(the one with the arrow)
* $ Move cursor to end of the current line
* w Move cursor to beginning of next word Basic vi commands7. b Move cursor back to beginning of preceding word
* :0<return> or 1G Move cursor to first line in file
* :n<return>or nG Move cursor to line n in file
* :$<return>or G Move cursor to last line in file

Screen Manipulation:

* ^f Move forward one screen
* ^b Move backward one screen
* ^d Move down(forward) one half screen
* ^u Move up(back)one half sreen
* ^l Redraws the screen
* ^r Redraws the screen,removing the deleted lines 

Adding,Changing,Deleting the text:

* u Undo whatever you just did(a simple toggle)

Inserting or Adding text:

* i Insert text before cursor,until<esc>hit
* I Insert text at beginning of current line,until<esc>hit
* a Append text after cursor,until<esc>hit
* A Append text to end of current line,until<esc>hit
* o Open and put text in a new line below current line,until<esc>hit
* O Open and put text in a new line above current line,until<esc>hit

Basic vi commandsChanging the text:

* r Replace single character under cursor(no <esc>needed)
* R Replace characters,starting with current cursor position,until<esc>hit
* cw Change the current word with new text,starting with the character under cursor,until<esc>hit
* cNw Change N words beginning with the character under cursor,until<esc>hit
* c change(replace)the characters in the current line,until<esc>hit
* cc change(replace)the characters in the current line,stopping when <esc>hit
* Ncc or cNc change(replace)the next N lines,starting with the current line,stopping when <esc>hit

Deleting the text:

* x Delete single character under cursor
* Nx Delete N characters, starting with character under cursor
* dw Delete the single word beginning with character under cursor
* dNw Delete N words beginning with character under cursor
* D Delete the remainder of the line,starting with current cursor position
* dd Delete entire current line
* Ndd or dNd Delete N lines beginning with the current line

Basic vi commandsCutting and pasting the text:

* yy Copy (yank,cut) the current line into buffer
* Nyy or yNy copy(yank,cut) the next N lines,including the current line, into the buffer
* p put(paste) the lines in the buffer into the text after the current line

Searching the text:

* /string Search forward for occurence of string in text
* ?string Search backward for occurence of string in text
* n Move to next occurence of search string
* N Move to next occurence of search string in opposite direction

Determining line numbers:

* :.= Returns line number of current line at bottom of screen
* := Returns the total number of lines at bottom of the screen
* ^g Provides the current line number, along with the total number of lines,in the file at the bottom of the screen

Saving and reading files:

* :r filename<return> Read file named filename and insert after current line(the line with arrow) Basic vi commands2. :w<return> Write current contents to a file named in original vi call
* :w newfile<return> Write current contents to a new file named newfile
* :12,35w smallfile<return> Write the contents of the line numbered 12 through 35 to a new file named smallfile
* :w! prevfile<return> Write current contents over a pre-existing file named prevfile

Command line history in ubuntu terminal

Here is few command for getting history in ubuntu terminal.

All history:

 history

 Output:
  483  cat /etc/nginx/nginx.conf 
  487  clear
  488  history
  490  which sh
  496  history 10

This will output like this. First part is the process ID and second part is command.

Get only last 10 history

 history 10

Search for history:

 history | grep nginx

Output: 
483  cat /etc/nginx/nginx.conf 

Running Previous Commands:

 !483
 
 Output:
 483  cat /etc/nginx/nginx.conf 

Hope this will help you to save time.

Happy coding 🙂

Install Oracle Java 7/8 (JDK and JRE) In Ubuntu 14.04

You can install Oracle Java 8 (JDK8 and JRE8) In Ubuntu 14.04 easily.

Add PPA repository and install Oracle Java 7/8 using the following commands:

Oracle Java 7:

 sudo add-apt-repository ppa:webupd8team/java
 sudo apt-get update
 sudo apt-get install oracle-java7-installer 

Oracle Java 8:

 sudo add-apt-repository ppa:webupd8team/java
 sudo apt-get update
 sudo apt-get install oracle-java8-installer 

Check installation:

 java -version
 
 Or,

 javac -version

Happy coding 🙂