How to round values in a column in a file
 

Hi,

I have a file test.txt.

cat test.txt
2014-07-25 00:00|739899.65|
2014-07-25 00:15|571028.09|
2014-07-25 00:30|64298.41|
2014-07-25 00:45|38963.27|
2014-07-25 01:00|166980.95|
2014-07-25 01:15|54133.68|
2014-07-25 01:30|610695.42|
2014-07-25 01:45|60568.26|
2014-07-25 02:00|122777.71|


how to round the numbers in 2nd column?

Run the command

Thanks a lot :-), its working fine :-)

Hello Sir,

could you please explain the parameters in above command, so that i'll keep in mind for future refrence.

$2 is the second column, actually i didn't get this part {$2=sprintf("%3.0f",$2)}1

{ } is a block

sprintf("%3.0f",$2)
means you format the value of $2 as float, 3 digits and 0 decimals => that means rounded).
$2 = sprintf... means $2 is set to rounded $2.

1 is a tricky line. It is a condition and always true, therefore the block belongs to this condition will be executed always. There is no block defined, it means the default will be used which simply prints the line. (it should have been written as 1 { print }).
for detailed explanation please read the man page of awk.... or ask

OFS is output field separator and FS is input field separator. Both are the Awk Built-in Variables. They define that the columns are separated with pipe (|).
$2 is second column. We need to modify this.
"sprintf()" is a string function. It acts in exactly the same way as "printf()", except that "sprintf()" assigns its output to a variable, not standard output.

You need to understand/learn awk to know how it works. Here is very small and good tutorial about awk which tells us about 8 in-built variables of the language. Take a look.
http://www.thegeekstuff.com/2010/01/...-filename-fnr/