How to delete line with echo?

Question

I know that I could delete the last three chars with:

echo -ne '\b\b\b'

But how can I delete a full line? I mean I don't want to use:

echo -ne '\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b'

...etc... to delete a long line.

Answer 1

You're looking for terminal escapes. In particular, to clear from the cursor position to the beginning of the line:

echo -e "\033[1K"

Or everything on the line, regardless of cursor position:

echo -e "\033[2K"

And you can do all sorts of other neat tricks with terminal escapes too.

Answer 2

You can use \b or \r to move the cursor back and then overwrite the printed character with a new character.

Note that neither \b nor \r deletes the printed characters. It just moves the cursor back. \b moves the cursor back one character and \r moves the cursor to the beginning of the line.

Example:

echo -e 'fooooo\b\b\b\bbar

will print

fobaro

while

echo -e 'fooooo\rbar'

will print:

barooo

If you want the previous characters "deleted" then you can use the following workaround:

echo -e 'fooooo\r      \rbar'

or

echo -e 'fooooo\rbar   '

(note the spaces after bar)

output:

bar   

note that there are now spaces after bar.

output with spaces highlighted

bar
   ^^^ spaces

for most use cases this will not matter. but if you, for example, modify background color you will notice the spaces.

---

Excerpt from man echo:

   If -e is in effect, the following sequences are recognized:

   \0NNN  the character whose ASCII code is NNN (octal)

   \\     backslash

   \a     alert (BEL)

   \b     backspace

   \c     produce no further output

   \f     form feed

   \n     new line

   \r     carriage return

   \t     horizontal tab

   \v     vertical tab

   NOTE: your shell may have its own version of echo, which usually super‐
   sedes the version described here.  Please refer to your  shell's  docu‐
   mentation for details about the options it supports.

Answer 3

If you want to clear the line, then I suggest you use a combination of the carriage return people are mentioning and terminfo.

# terminfo clr_eol
ceol=$(tput el)
echo -ne "xyzzyxyzzy\r${ceol}foobar"

This will write xyzzyxyzzy, then return to the beginning of the line and send the "clear to end of line" sequence to the terminal, then write foobar. The -n makes echo not add a newline after the foobar.

Answer 4

Here's an example using echo's no newline -n and carriage return \r options.

#!/bin/bash

CHECK_MARK="\033[0;32m\xE2\x9C\x94\033[0m"

echo -e "\n\e[4mDoing Things\e[0m"
echo -n "doing thing 1..."
sleep 1
echo -e "\\r${CHECK_MARK} thing 1 done"

Answer 5

You explicitly ask for echo, but this request pins you down. Here's an approach that uses bash's builtin printf command with brace expansion:

printf 'fooooooooo' # 10 characters
printf '\r'; printf ' %0.s' {0..9} # 10 expansions of the space character

Answer 6

Here is a countdown timer example I use:

i=10
while [ $i -gt 0 ]; 
do 
  printf "$i seconds remaining       " && printf '\r\033[1B'
  i=`expr $i - 1`
  sleep 1
  printf '\033[1A'
done

Answer 7

Instead of echo -en "\r" you might also find the printf "\r" command as useful. This way you can format the string. e.g.:

for sec in {1..100}; do printf "\r %04d" ${sec}; sleep 0.1; done

I usually do that as well when operating with slow file parsing to display the filename currently in progress without creating a list

Answer 8

As question is delete the full line

I have used below command with combination of echo and sed to delete line

After execution of command result will be empty.since while line will be replaced with none

command

echo  "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b" | sed -r "s/.*//g"