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@pieman72
Last active March 29, 2021 01:07
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Hex to ANSI color code converter
function hex_to_ansi(){
# Get the individual color components as decimals
HEX=$(echo "$1" | tr -d '#' | tr '[:lower:]' '[:upper:]')
DIGITS=$(( ${#HEX} / 3 ))
R=$(( 16#${HEX:$(( DIGITS * 0 )):$DIGITS} ))
G=$(( 16#${HEX:$(( DIGITS * 1 )):$DIGITS} ))
B=$(( 16#${HEX:$(( DIGITS * 2 )):$DIGITS} ))
# Handle grey ramp
if [ "`echo $(( R-G )) | tr -d '-'`" -lt 16 ]\
&& [ "`echo $(( R-B )) | tr -d '-'`" -lt 16 ]\
&& [ "`echo $(( G-B )) | tr -d '-'`" -lt 16 ]; then
GREY=$(( (R+G+B)/3 ))
if [ "$GREY" -lt 5 ]; then CC="0"
elif [ "$GREY" -gt 246 ]; then CC=15
else CC=$(( (GREY-3)/10 + 232 )); fi
# Handle 16 basic colors
elif [ "`echo $(( R-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( G-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( B-0 )) | tr -d '-'`" -lt 24 ]; then
CC="0"
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( B-0 )) | tr -d '-'`" -lt 24 ]; then
CC=1
elif [ "`echo $(( R-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-0 )) | tr -d '-'`" -lt 24 ]; then
CC=2
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-0 )) | tr -d '-'`" -lt 24 ]; then
CC=3
elif [ "`echo $(( R-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( G-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=4
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=5
elif [ "`echo $(( R-0 )) | tr -d '-'`" -lt 24 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=6
elif [ "`echo $(( R-192 )) | tr -d '-'`" -lt 18 ]\
&& [ "`echo $(( G-192 )) | tr -d '-'`" -lt 18 ]\
&& [ "`echo $(( B-192 )) | tr -d '-'`" -lt 18 ]; then
CC=7
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=8
elif [ "`echo $(( R-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=9
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=10
elif [ "`echo $(( R-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( G-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( B-128 )) | tr -d '-'`" -lt 14 ]; then
CC=11
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-255 )) | tr -d '-'`" -lt 10 ]; then
CC=12
elif [ "`echo $(( R-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( G-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( B-255 )) | tr -d '-'`" -lt 10 ]; then
CC=13
elif [ "`echo $(( R-128 )) | tr -d '-'`" -lt 14 ]\
&& [ "`echo $(( G-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( B-255 )) | tr -d '-'`" -lt 10 ]; then
CC=14
elif [ "`echo $(( R-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( G-255 )) | tr -d '-'`" -lt 10 ]\
&& [ "`echo $(( B-255 )) | tr -d '-'`" -lt 10 ]; then
CC=15
# Handle 6x6x6 color cube
else
CC=16
if [ "$R" -lt 48 ]; then :
elif [ "$R" -lt 115 ]; then CC=$(( CC+(36*1) ))
elif [ "$R" -lt 156 ]; then CC=$(( CC+(36*2) ))
elif [ "$R" -lt 196 ]; then CC=$(( CC+(36*3) ))
elif [ "$R" -lt 235 ]; then CC=$(( CC+(36*4) ))
else CC=$(( CC+(36*5) )); fi
if [ "$G" -lt 48 ]; then :
elif [ "$G" -lt 115 ]; then CC=$(( CC+(6*1) ))
elif [ "$G" -lt 156 ]; then CC=$(( CC+(6*2) ))
elif [ "$G" -lt 196 ]; then CC=$(( CC+(6*3) ))
elif [ "$G" -lt 235 ]; then CC=$(( CC+(6*4) ))
else CC=$(( CC+(6*5) )); fi
if [ "$B" -lt 48 ]; then :
elif [ "$B" -lt 115 ]; then CC=$(( CC+1 ))
elif [ "$B" -lt 156 ]; then CC=$(( CC+2 ))
elif [ "$B" -lt 196 ]; then CC=$(( CC+3 ))
elif [ "$B" -lt 235 ]; then CC=$(( CC+4 ))
else CC=$(( CC+5 )); fi
fi
# Use the color for either background or foreground
if [ -z "$2" ]; then
echo "[38;5;"$CC"m"
else
echo "[48;5;"$CC"m"
fi
}
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