Is there a better way to erase a line than echo " "?

I am wanting to erase several (let's say 10) lines on the screen using bash.

I know this can be done by开发者_运维知识库:

for x in `seq 1 10`; do
  echo "                                                    "
done

but there must be a better way.

Something like:

echo -n10 --blank

or

echo -n10 space(80)

or something similar.

Any ideas?

It's not necessary to use seq in Bash:

for x in {1..10}
do
    dosomething
done

Let's say you want to clear 10 lines starting at the 8th line on the screen, you can use tput to move the cursor and do the clearing:

tput cup 8 0        # move the cursor to line 8, column 0
for x in {1..10}
do
    tput el          # clear to the end of the line
    tput cud1        # move the cursor down
done
tput cup 8 0        # go back to line 8 ready to output something there

See man 5 terminfo for more information.

Try

$ printf "%80s" ""

to get 80 spaces, without a trailing newline. If you want to know how many spaces you need, $COLUMNS is probably want you want:

$ printf "%${COLUMNS}s" ""

will give you a blank line of the appropriate length even if you've resized your window. The "clear" command will clear the entire window, too.

You can use echo still with terminal escapes:

ceol=$(tput el)
for x in `seq 10 -1 10`; do
   echo -n -e "\r${ceol}Counting $x"
   sleep 1
done

Or if you prefer:

echo -n -e "\033[1K\rCounting $x"

• -n do not output \n\r at end of line (so cursor stays at end of last character)
• \r return to start of line
• ${ceol} clear to end of line (so comes after \r)
• \033[1K clear to start of line (so comes before \r)

Nb. made it count backwards to prove that the line is cleared; i.e. when printing 9, it shows that the 0 from 10 has been cleared.

I would use this:

for x in $(seq 10); do
  tput cup ($x)-1 0
  tput el                                               
done