Write over previous line in bash

seq 1 1000000 | while read i; do echo -en "\r$i"; done

0
By: evandrix
2012-03-15 14:13:04

These Might Interest You

  • A common mistake in Bash is to write command-line where there's command a reading a file and whose result is redirected to that file. It can be easily avoided because of : 1) warnings "-bash: file.txt: cannot overwrite existing file" 2) options (often "-i") that let the command directly modify the file but I like to have that small function that does the trick by waiting for the first command to end before trying to write into the file. Lots of things could probably done in a better way, if you know one... Show Sample Output


    2
    buffer () { tty -s && return; tmp=$(mktemp); cat > "${tmp}"; if [ -n "$1" ] && ( ( [ -f "$1" ] && [ -w "$1" ] ) || ( ! [ -a "$1" ] && [ -w "$(dirname "$1")" ] ) ); then mv -f "${tmp}" "$1"; else echo "Can't write in \"$1\""; rm -f "${tmp}"; fi }
    Josay · 2009-07-27 20:21:15 3
  • hold period (or whatever character) and hit enter after a second. You need to make the next line of periods the same length as the previous line... score starts at 0 and increase each time length of line is same.


    1
    while $8;do read n;[ $n = "$l" ]&&c=$(($c+1))||c=0;echo $c;l=$n;done
    florian · 2010-03-31 00:41:08 0
  • If you would like to edit a previous command, which might be long and complicated, you can use the fc (I think it stands for fix command). Invoke fc alone will edit the last command using the default editor (specified by $FCEDIT, $EDITOR, or emacs, in that order). After you make the changes in the editor, save and exit to execute that command. The fc command is more flexible than what I have described. Please 'man bash' for more information.


    10
    fc [history-number]
    haivu · 2009-03-20 15:09:43 6
  • write first line `#!`


    -8
    { echo -n '#!'; which bash; } > script.sh
    kev · 2012-02-06 01:03:22 0

What Others Think

Er... evandrix, what's this command supposed to do? Its output is on a new line, so it doesn't obscure anything. It doesn't clear the screen, it doesn't fill the terminal's buffer. It just spends 20 seconds counting to one million.
flatcap · 326 weeks and 4 days ago
He simulated a counter (seq command without line feed)
knoppix5 · 326 weeks and 4 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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