Don't blindly run editable github gist with bash

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ItsDrike 2021-08-16 17:31:26 +02:00
parent 1de5142b86
commit 182a68612f
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2 changed files with 102 additions and 1 deletions

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@ -217,7 +217,6 @@ alias path='echo -e ${PATH//:/\\n}' # Print each PATH entry on a separate line
alias unsudo='sudo -k' # Reset sudo timeout (sudo will require password) alias unsudo='sudo -k' # Reset sudo timeout (sudo will require password)
alias vimwiki='vim -c VimwikiIndex' # Open vimwiki index alias vimwiki='vim -c VimwikiIndex' # Open vimwiki index
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"' alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"'
alias colors-256='curl -s https://gist.githubusercontent.com/HaleTom/89ffe32783f89f403bba96bd7bcd1263/raw/ | bash' # Show color table
alias tty-clock='tty-clock -Ssc' # Terminal clock screensaver alias tty-clock='tty-clock -Ssc' # Terminal clock screensaver
alias rick='curl -s -L https://raw.githubusercontent.com/ItsDrike/rickrollrc/master/roll.sh| bash' # Terminal rickroll alias rick='curl -s -L https://raw.githubusercontent.com/ItsDrike/rickrollrc/master/roll.sh| bash' # Terminal rickroll

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@ -0,0 +1,102 @@
#!/bin/bash
# # Print out 256 colors, with each number printed in its corresponding colour
#
# This file is uploaded on <https://gist.githubusercontent.com/HaleTom/89ffe32783f89f403bba96bd7bcd1263/raw/>
# It was originally intended to be used as an alias that curled this URL and piped it into bash, however
# this is very unsafe as the owner can change the content of this gist at his convenience, meaning it was
# a potential security vulnerability. This is a script version of this alias to avoid this issue.
#
# The copyright for this file belongs to the original author: Tom Hale, 2016
# This file was released under MIT license
set -eu # Fail on errors or undeclared variables
printable_colours=256
# Return a colour that contrasts with the given colour
# Bash only does integer division, so keep it integral
function contrast_colour {
local r g b luminance
colour="$1"
if (( colour < 16 )); then # Initial 16 ANSI colours
(( colour == 0 )) && printf "15" || printf "0"
return
fi
# Greyscale # rgb_R = rgb_G = rgb_B = (number - 232) * 10 + 8
if (( colour > 231 )); then # Greyscale ramp
(( colour < 244 )) && printf "15" || printf "0"
return
fi
# All other colours:
# 6x6x6 colour cube = 16 + 36*R + 6*G + B # Where RGB are [0..5]
# See http://stackoverflow.com/a/27165165/5353461
# r=$(( (colour-16) / 36 ))
g=$(( ((colour-16) % 36) / 6 ))
# b=$(( (colour-16) % 6 ))
# If luminance is bright, print number in black, white otherwise.
# Green contributes 587/1000 to human perceived luminance - ITU R-REC-BT.601
(( g > 2)) && printf "0" || printf "15"
return
# Uncomment the below for more precise luminance calculations
# # Calculate percieved brightness
# # See https://www.w3.org/TR/AERT#color-contrast
# # and http://www.itu.int/rec/R-REC-BT.601
# # Luminance is in range 0..5000 as each value is 0..5
# luminance=$(( (r * 299) + (g * 587) + (b * 114) ))
# (( $luminance > 2500 )) && printf "0" || printf "15"
}
# Print a coloured block with the number of that colour
function print_colour {
local colour="$1" contrast
contrast=$(contrast_colour "$1")
printf "\e[48;5;%sm" "$colour" # Start block of colour
printf "\e[38;5;%sm%3d" "$contrast" "$colour" # In contrast, print number
printf "\e[0m " # Reset colour
}
# Starting at $1, print a run of $2 colours
function print_run {
local i
for (( i = "$1"; i < "$1" + "$2" && i < printable_colours; i++ )) do
print_colour "$i"
done
printf " "
}
# Print blocks of colours
function print_blocks {
local start="$1" i
local end="$2" # inclusive
local block_cols="$3"
local block_rows="$4"
local blocks_per_line="$5"
local block_length=$((block_cols * block_rows))
# Print sets of blocks
for (( i = start; i <= end; i += (blocks_per_line-1) * block_length )) do
printf "\n" # Space before each set of blocks
# For each block row
for (( row = 0; row < block_rows; row++ )) do
# Print block columns for all blocks on the line
for (( block = 0; block < blocks_per_line; block++ )) do
print_run $(( i + (block * block_length) )) "$block_cols"
done
(( i += block_cols )) # Prepare to print the next row
printf "\n"
done
done
}
print_run 0 16 # The first 16 colours are spread over the whole spectrum
printf "\n"
print_blocks 16 231 6 6 3 # 6x6x6 colour cube between 16 and 231 inclusive
print_blocks 232 255 12 2 1 # Not 50, but 24 Shades of Grey