Can I print until the end of the line?-CodePudding

Consider this small example:

printf "Loading data..."; \
sleep 5; \
echo -e "\rThis is my cool data point."

This brings, of course, Loading data..., and after 5 seconds, that will be overwritten by This is my cool data point..

But what if the text printed out after the \r is shorter as the first line?

printf "Loading data..."; \
sleep 5; \
echo -e "\rNo data."

...brings No data.data... after the waiting time.

Do I have to keep track of the longest possible line and print "\rNo data. " or is there any "magic character" that fills the line until its end in a normal terminal?

CodePudding user response：

You can delete to end of line with tput el. So you can do:

eol=$(tput el)
printf "Loading data..."
sleep 5
printf "\rNo data.${eol}\n"

It's not really a "magic character" so much as a "magic sequence", and the actual values that are used may vary with the terminal. tput will (should) do the right thing and give you a reasonably portable method. Attempting to determine precisely which sequence to use is a futile effort.

CodePudding user response：

Another solution would be:

#!/bin/bash

msg1='Loading data...'
msg2='No data.'
printf '%s' "$msg1"
sleep 5
printf '\r%*s\n' $(( -(${#msg1} > ${#msg2} ? ${#msg1} : ${#msg2}) )) "$msg2"

This appends trailing spaces to the line if the length of msg1 is greater than that of msg2.