Bash Awk 命令混淆

Question

I was checking a piece of code and I can't fully understand it:

var1=`awk -F , '{printf "%.0f\n", $1*17/1000}' $somefile`;

Let's say that the number it receives from the file is 1000, it multiplies it by 17 and divides by 1000, but before that, there's this: "%.0f\\n" I know how rest of the calculations go, but that part confuses me. As far as I understand it, it's calculating a desimal of something and prints a newline. An answer with a pit of explanation of the awk command in whole would be appreciated :D

Answer 1

It sets the number of decimal points to zero (truncates the number) after the computation. You can find more information here

You can try it out yourself by typing

awk -F, '{printf "%.0f\n", $1*17/1000}'

on the command line, it will then convert your input for each entered line, but perhaps this will be more intuitive. (Control-D to exit)

awk -F, '{printf "%.0f\n", $1}'

ps. Note that this is equivalent to integer formatting %d or %i (no decimal points)