How to create a ____________ in 100% in shell script?

manuel19 · 07-05-2013, 11:26 AM

Hi, I'm creating a shell script.
I need a way to create a Line 100% Width like menus.

Ex:

___________________________________(100%width)
My Application title
___________________________________(100%width)

1 - For exit.
2 - Read
...
..
..

How can i do that?

Kustom42 · 07-05-2013, 01:03 PM

Something like this is not going to be easily done just within BASH. I would recommend perl for something like this.

Here is CPAN module that would provide the progress bar you are looking for.

http://search.cpan.org/~szabgab/Term...ProgressBar.pm

Perl also allows you to create menus easily enough.

You could try and use curses with bash but not sure if that would give you what you are looking for easily:

http://www.tldp.org/HOWTO/NCURSES-Programming-HOWTO/

suicidaleggroll · 07-05-2013, 01:41 PM

The COLUMNS environment variable holds the terminal width, so something like:

Code:

for ((i=0;i<$COLUMNS;i++)); do echo -n _; done

Would print a line the whole width of the terminal.

onebuck · 07-05-2013, 05:28 PM

Moved: This thread is more suitable in <Programming> and has been moved accordingly to help your thread/question get the exposure it deserves.

grail · 07-06-2013, 05:54 AM

My first question would be, 100% of what?

Xeratul · 07-06-2013, 01:23 PM

#!/bin/bash colmax=$(tput cols) lig=$(tput lines)

tput gives you the cols/lines

To count, you may use:
cat "$1" | awk 'END {print NR}'

and so on.

I would be you, I would learn coding in C language. ask me, I can guide you through ur learning

apt-get install gcc
and also ncurses, that will help

konsolebox · 07-07-2013, 04:08 AM

___________ in 100%????

I'm not sure what you really want but I think you could make use of the dialog command. And if you want to generate a line you just make use of echo with the use of substring expansion I think. That's less expensive compared to multiple calls to echo in a loop.

Code:

LINE=__________
for (( I = 1; I <= 5; ++I )); do  ## or "for {1..5}; do" in newer Bash probably 4.0
    LINE=${LINE}${LINE}  # or LINE+=${LINE} in Bash 3.1+
done

echo "${LINE:0:100}"  ## Change 100 to any number depending on the needed line's length
echo "My Application title"
echo "${LINE:0:100}"

David the H. · 07-07-2013, 04:37 AM

Code:

printf -v line '%.*d\n' "$COLUMNS"
echo "${line//0/_}"

"*" is a printf format feature that gets substituted by the numerical value of the first non-format argument.

You only need to ensure that the COLUMNS variable or similar is available.

I'm trying to get the number of columns or lines of my terminal but the variables COLUMNS / LINES are always empty
http://mywiki.wooledge.org/BashFAQ/091

Finally, as printed above it requires bash/ksh features, but it could be replicated in other shells with command substitution and something like tr.

konsolebox · 07-07-2013, 05:49 AM

Just consider that printf -v is a new feature available to versions of Bash not earlier than 4.0 so consider using it if compatibility to earlier versions is not necessary.

As for Xeratul's suggestion to tput, you could also have stty to get the number of columns:

Code:

read LINES COLUMNS < <(exec stty size)
echo "$COLUMNS"

Putting those two together we could have something like:

Code:

#!/bin/bash

shopt -s extglob

if [[ $(type -t tput 2>/dev/null) == file ]] && read COLUMNS < <(exec tput cols) && [[ $COLUMNS == +([[:digit:]]) && COLUMNS -gt 0 ]]; then
    :
elif [[ $(type -t stty 2>/dev/null) == file ]] && read __ COLUMNS < <(exec stty size) && [[ $COLUMNS == +([[:digit:]]) && COLUMNS -gt 0 ]]; then
    :
else
    echo "Unable to find number of columns for the screen."
    exit 1
fi

# Do something here ...

David the H. · 07-07-2013, 06:11 AM

Actually -v has been available since 3.1, although it was expanded to support array elements in 4.1*.

http://wiki.bash-hackers.org/scripting/bashchanges

But if you don't have it for some reason, just capture the output instead.

Code:

line=$( printf '%.*d\n' "$COLUMNS" )

(*Still only a single fixed entry though. But wouldn't it be great if it could set an entire array, with one element per iteration?)

konsolebox · 07-07-2013, 06:58 AM

Quote:

Originally Posted by David the H.

Actually -v has been available since 3.1, although it was expanded to support array elements in 4.1*.

Yes you're correct. Sorry I misread an online post.

Quote:

printf '%.*d\n' "$COLUMNS"

Yes it wouldn't be a bad idea to use it over the initial iteration.