Create asterisk border around output in terminal? - bash

Question

I need to create a border around the output of a command in terminal so that if, for example, the output of a command is this:
Apple
Paper Clip
Water
It will become this:
/==========\
|Apple |
|Paper Clip|
|Water |
\==========/
Thanks ahead of time for any and all responses.
-C.L

Answer 1

awk seems like the least insane way to go about this:
command | expand | awk 'length($0) > length(longest) { longest = $0 } { lines[NR] = $0 } END { gsub(/./, "=", longest); print "/=" longest "=\\"; n = length(longest); for(i = 1; i <= NR; ++i) { printf("| %s %*s\n", lines[i], n - length(lines[i]) + 1, "|"); } print "\\=" longest "=/" }'
expand replaces tabs that may be in the output with the appropriate number of spaces to keep the look of it the same (this is to make sure that every byte of output is rendered with the same width). The awk code works as follows:
length($0) > length(longest) { # Remember the longest line
longest = $0
}
{ # also remember all lines in order
lines[NR] = $0
}
END { # when you have everything:
gsub(/./, "=", longest) # build a line of = as long as the longest
# line
print "/=" longest "=\\" # use it to print the top bit
n = length(longest) # format the content with left and right
for(i = 1; i <= NR; ++i) { # delimiters; spacing through printf
printf("| %s %*s\n", lines[i], n - length(lines[i]) + 1, "|")
}
print "\\=" longest "=/" # print bottom bit.
}
The most insane way to do it, and I dare you to dispute this, is with sed:
#!/bin/sed -f
# assemble lines in the hold buffer, preceded by the left delimiter
s/^/| /
1h
1!H
$!d
# make a copy of it in the pattern space
x
h
# isolate the longest line (or rather: a line of = as long as the longest
# line)
s/[^\n]/=/g
:a
/^\(=*\)\n\1/ {
s//\1/
ba
}
//! {
s/\n=*//
ta
}
# build top bit, print it
s,.*,/&\\,
p
# build measuring stick
s,.\(.*\).,=\1,
# for all lines in the output:
:lineloop
# fetch the line
G
s/^\(=*\n\)\([^\n]*\).*/\1\2/
# replace it with = to get a second measuring stick
s/[^\n]/=/g
# fetch another copy of the line
G
s/^\(=*\n=*\n\)\([^\n]*\).*/\1\2/
# inner loop:
:spaceloop
# while the line measuring stick is not as long as the overall measuring
# stick
/^\(=*\)\n\1/! {
# append a = to it and a space to the line for output
s/\n/\n=/
s/$/ /
b spaceloop
}
# once that is done, append the second delimiter
s/$/|/
# remove one measuring stick
s/=*\n//
# put the second behind the actual line
s/\(.*\)\n\(.*\)/\2\n\1/
# print the line
P
# remove it. Only the measuring stick remains and can be reused for the
# next line
s/.*\n//
# do this while there are more lines to be processed
x
/\n/ {
s/[^\n]*\n//
x
b lineloop
}
# then build the bottom bit and print it.
x
s/=/\\/
s/$/\//
Put that in a file foo.sed, use command | expand | sed -f foo.sed. But only do it once to confirm that it works. You don't want to run something like that in production.

Answer 2

Not in the language you were looking for, but succinct and readable:
#!/usr/bin/env ruby
input = STDIN.read.split("\n")
width = input.map(&:size).max + 2
bar = '='*(width-2)
puts '/' + bar + '\\'
input.each {|i| puts "|"+i+" "*(width-i.size-2)+"|" }
puts '\\'+ bar + '/'
You can save it in a file, chmod +x it, and pipe your input into it.
If you "need" to have it in a one-liner:
echo e"Apple\nPaper Clip\nWater" |
ruby -e 'i=STDIN.read.split("\n");w=i.map(&:size).max+2;b="="*(w-2);i.map! {|j| "|"+j+" "*(w-j.size-2)+"|" };i.unshift "/"+b+"\\"; i<<"\\"+b+"/";puts i'