CODEWITHSUNDEEP
linuxbashterminal
exebook
exebook

Reputation: 33920

Draw a horizontal line from dash character occupying the full width of a terminal in bash

I need a command that will draw a horizontal "line" in the terminal. The line must be exactly the width of the terminal long (regardless of a current terminal width) and consist of a dash character (although a unicode symbol for a horizontal line can be also used).

It is better if it can be colored.

I need to use it like this:

echo some text
drawline
echo more text

And the output would look something like this:

echo some text
---------------------------------------------------------------------------------
echo more text

Upvotes: 34

Views: 29447

Answers (6)

cglacet
cglacet

Reputation: 10944

I'll add some details to the current top answer. You can use the following "hack" (also as suggested here):

printf '%.s─' $(seq 1 $(tput cols))

Notice how this doesn't use the simple dash - but instead the box drawing dash ─. This way consecutive dashes actually connects which prints a nice continuous line:

This nice line   ────────────────────────────
And not this one ----------------------------

You can for example use this to show a line before (and/or after) every command registering hooks using zsh

# ~/.zshrc
draw_hline=false
preexec() {
  if [[ $1 == ls* ]]; then
    hline
    draw_hline=true
  fi
}

precmd() {
  if [ $draw_hline = true ]; then
    hline
    echo
  fi
  draw_hline=false
}

Registering hooks using bash can probably be done in a very similar way using this.

Upvotes: 21

Deepak Deore
Deepak Deore

Reputation: 322

you can use tput to set colors and printf to print line according to number of columns.

export RED=$(tput setaf 1 :-"" 2>/dev/null)
export GREEN=$(tput setaf 2 :-"" 2>/dev/null)
export YELLOW=$(tput setaf 3 :-"" 2>/dev/null)
export BLUE=$(tput setaf 4 :-"" 2>/dev/null)
export RESET=$(tput sgr0 :-"" 2>/dev/null)

echo $GREEN some text $RESET
echo $RED; printf -- "-%.0s" $(seq $(tput cols)); echo $RESET
echo $YELLOW more text $RESET

enter image description here

Upvotes: 3

Inoperable
Inoperable

Reputation: 1509

Super simple horizontal ruler:

repeat $(tput cols) echo -ne "-";

Upvotes: -1

Shakiba Moshiri
Shakiba Moshiri

Reputation: 23864

A simple Perl one-liner
stty size | perl -ale 'print "-"x$F[1]'

NOTE
you can see the height and width of your terminal with stty size

enter image description here

Upvotes: 4

cb0
cb0

Reputation: 8613

In bash and zsh there is the $COLUMNS variable which you can use.

I use this line for that purpose:

printf %"$COLUMNS"s |tr " " "-"

You can also use seq, but this is not as intuitive as the other solution:

seq -s- $COLUMNS|tr -d '[:digit:]'

Edit:

It seems that $COLUMNS is a local bash variable and you will need to export it. So now there are (at least) 2 options.

  1. Export the variable before you call the script:

    export COLUMNS; ./your_script.sh

  2. Use tput as Zumo de Vidrio suggests.

    printf %"$(tput cols)"s |tr " " "-"

Upvotes: 23

Zumo de Vidrio
Zumo de Vidrio

Reputation: 2091

Try with:

echo some text
printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
echo some text

Upvotes: 35

Related Questions