Scripting on Jaymin Patel

English to Gujarati Dictionary in Linux

Sun, 15 Apr 2012 12:50:00 +0530

This post is for all Linux Desktop users from Gujarat who are looking for an English to Gujarati dictionary in Linux Desktop.

In Linux, for English to Gujarati dictionary we open up a browser for an online database, but here we achieved it in just one tiny shell script.

The constraint is that it requires internet connection as it uses an online database, but the good thing about this tool is that it has an updated dictionary database and it supports clipboard capture so we don't have to type a word each time.

Auto Logout in Linux

Sun, 16 May 2010 11:41:00 +0530

Almost everyone is forgetful and used to leave the Linux/Unix login session open without logging out. So, how to make sure all the Linux systems will automatically logout users after idle for certain minutes?

In fact, the simplest way is to configure the TMOUT shell variable!

export TMOUT=60

This export command will immediately get the Linux OS to automatically logout a user after his/her login session being idle for 60 seconds or 1 minute!

Setup Proxy Setting in a Text-Based Linux Machine

Sun, 16 May 2010 11:32:00 +0530

In a generic scenario, internet access is running through a proxy in small offices. In that case, Linux command line utilities that require internet access to work like wget, curl, yum, and apt-get don't work. The questions that come up:

How to install packages using proxy by yum?
How to install packages using proxy by apt-get?
How to download a file from command line using wget?

All these utilities depend on shell variables http_proxy and ftp_proxy to work with a proxy.

Argument List Too Long

Sun, 16 May 2010 11:25:00 +0530

Suppose, there are 1,30,000 files to move from one directory to another, what will happen?

# mv *.txt test

Oh!! There is an error:

mv: Argument list too long.

What to do? Simple answer is to use find command:

# find . -maxdepth 1 -name '*.txt' -exec mv '{}' test \;

Here,

Option	Description
`.`	Defines search directory
`-maxdepth`	Disables recursive search. With `-maxdepth 1` it will only search in current directory
`-name`	String to be searched
`-exec`	Applies a command to set of files that have been searched
`{}`	Inserts each found file into given command after `-exec`
`\;`	Indicates the exec command line has ended

The above example searches for *.txt files in current directory and moves it to the test directory.

bad interpreter: No such file or directory

Sun, 16 May 2010 11:21:00 +0530

Sometimes shell scripts in Linux give this error:

bash: ./t1.sh: /bin/sh^M: bad interpreter: No such file or directory

This happens when files are transferred from a Windows machine to a Linux machine. Different operating systems use different line ending characters:

OS	Line End	Character
UNIX/Linux	LF	`\n`
DOS/Windows	CRLF	`\r` and `\n`
Mac	CR	`\r`

CR (Carriage Return): Return cursor to left margin, Ctrl-M (^M) or hex 0D LF (Linefeed): Move cursor down, Ctrl-J (^J) or hex 0A