UNIX : What is /dev/null ?

/dev/null is a file where you can discard the output of the command executed.
This file is also called as Bit Bucket.

eg :

>ls -ltr > /dev/null
>

Here the output of command ls is never shown on terminal STDOUT. It is redirected to bit bucket.

Sometimes we need not display the output as well as error message of command.In this case use the following command.

> command > /dev/null 2>&1

The command output is redirected to /dev/null.Also the error output, STDERR (which is called by 2) is redirected to STDOUT (called as 1 ).That means the error will be redirected to /dev/null.

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Pokemon Go download link

Pokemon go has become the buzz word in tech industry now. Nintendo, the Japanese video game company are the creates of this game. Its first of it kind to integrate a game with augmented reality , so people has to go out to real world with there android or iPhone to catch em all . You can download Pokemon go from this link.

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String data types STRING VARCHAR CHAR TINYINT SMALLINT INT BIGINT FLOAT DOUBLE DECIMAL BOOLEAN TIMESTAMP DATE

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Sometimes we need to ignore multiple lines with certain words and get the list out of the file. usually it will be a log file to read . The below grep command can be used to ignore multiple words present in a text file. Lets say the file contain $ cat list.txt apple orange apple banana papaya Now we need to ignore line with orange , banana and papaya . So we can use the below grep command. $ cat list.txt | grep -Ev "orange|banana|papaya" apple apple It will ignore lines with the words in -v part of grep.

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