Convert a character from and to its decimal, binary, octal, or hexadecimal representations in BASH / Shell - unicode

Question

How to convert a character from and to its decimal, binary, octal, or hexadecimal representations in BASH / Shell ?

Answer 1

Convert a character from and to its decimal, binary, octal, or hexadecimal representations in BASH with printf and od
Some relevant documentation and Q&A:
od man pages:
https://www.gnu.org/software/coreutils/manual/html_node/od-invocation.html
printf man pages:
https://www.gnu.org/software/coreutils/manual/html_node/printf-invocation.html
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/printf.html
What is the difference between UTF-8 and Unicode?
How do I print an ASCII character by different code points in Bash?
How to print an octal value's corresponding UTF-8 character in bash?
Unicode char representations in BASH / shell: printf vs od
Convert binary, octal, decimal and hexadecimal values between each other in BASH / Shell
Convert a character from and to its decimal representation
single_ascii_char="A"
echo -n $single_ascii_char | od -A n -t d1
65
printf %d "'$single_ascii_char"
65
code=65
printf "\u$(printf %04x $code)\n" # use \u for up to 4 hexadecimal digits
A
printf "\U$(printf %08x $code)\n" # use \U for up to 8 hexadecimal digits
A
single_unicode_char="😈"
printf %d "'$single_unicode_char"
128520
echo -n $single_unicode_char | iconv -t UTF-32LE | od -A n -t d # d or u, d4, u4, dI, dL
128520 # or UTF-32BE, depending on system's endianness
code=128520
printf "\u$(printf %04x $code)\n" # use \u for up to 4 hexadecimal digits
ὠ8
printf "\U$(printf %08x $code)\n" # use \U for up to 8 hexadecimal digits
😈
Convert a character from and to its binary representation
single_ascii_char="A"
echo "obase=2; $(printf %d "'$single_ascii_char")" | bc
1000001
code="1000001"
printf "\u$(printf %04x $((2#$code)) )\n" # use \u for up to 4 hexadecimal digits
A
printf "\U$(printf %08x $((2#$code)) )\n" # use \U for up to 8 hexadecimal digits
A
single_unicode_char="😈"
echo "obase=2; $(printf %d "'$single_unicode_char")" | bc
11111011000001000
code="11111011000001000" # with or without leading 0s
printf "\u$(printf %04x $((2#$code)) )\n" # use \u for up to 4 hexadecimal digits
ὠ8
printf "\U$(printf %08x $((2#$code)) )\n" # use \U for up to 8 hexadecimal digits
😈
Convert a character from and to its octal representation
single_ascii_char="A"
printf %o "'$single_ascii_char"
101
echo -n $single_ascii_char | od -A n -t o1
101
code="\101"
printf %b "$code\n"
A
printf "$code\n"
A
single_unicode_char="😈"
printf %o "'$single_unicode_char"
373010
echo -n $single_unicode_char | iconv -t UTF-32LE | od -A n -t o # or o4
00000373010 # or UTF-32BE, depending on system's endianness
code="00000373010" # insert at least one leading 0 for printf to understand it's an octal
printf "\U$(printf %08x "$code")\n"
😈
echo -n "$single_unicode_char" | od -A n -t c # c or o1
360 237 230 210
code="\360\237\230\210"
printf %b "$code\n"
😈
printf "$code\n"
😈
Convert a character from and to its hexadecimal representation
single_ascii_char="A"
printf %x "'$single_ascii_char"
41
echo -n "$single_ascii_char" | od -A n -t x1
41
code="41"
printf "\u$code\n" # use \u for up to 4 hexadecimal digits
A
printf "\U$code\n" # use \U for up to 8 hexadecimal digits
A
single_unicode_char="😈"
printf %x "'$single_unicode_char"
1f608
printf %X "'$single_unicode_char"
1F608
echo -n $single_unicode_char | iconv -t UTF-32LE | od -A n -t x
0001f608 # or UTF-32BE, depending on system's endianness
code="1f608"
printf "\u$code\n" # use \u for up to 4 hexadecimal digits
ὠ8
printf "\U$code\n" # use \U for up to 8 hexadecimal digits
😈
printf %#x "'$single_unicode_char"
0x1f608
printf %#X "'$single_unicode_char"
0X1F608
code="0x1f608"
printf "\u$(printf %04x $code)\n" # use \u for up to 4 hexadecimal digits
ὠ8
printf "\U$(printf %08x $code)\n" # use \U for up to 8 hexadecimal digits
😈
echo -n "$single_unicode_char" | od -A n -t x1
f0 9f 98 88
code="\xf0\x9f\x98\x88"
printf %b "$code\n"
😈
printf "$code\n"
😈