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/bin/sh would be dash what is the correct syntax for printf to display certain ascii character using hex or dex code in dash? let's say i want to printf a dollar sign ($). which hex or dec code should be used and how?

roaima
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  • Related: [Why does printf byte formatting fail when executed under `dash`?](https://unix.stackexchange.com/questions/627036/why-does-printf-byte-formatting-fail-when-executed-under-dash) – steeldriver Jun 08 '21 at 20:23

1 Answers1

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If you want to go from the character code to the character itself, you include the character code in the printf format string, escaped with a backslash, in octal.

E.g. printf "\044\n" prints $ (and a newline).

In Bash and other shells, you could use hex, \x24, but that's not standard and doesn't work in Dash.

You could nest another printf in a command substitution to convert from hex or decimal to octal, though. Both of these would print $ (and a newline):

printf "\\$(printf %o 36)\n"
printf "\\$(printf %o 0x24)\n"
ilkkachu
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  • Nice.printf "\044\n" works well. –  Jun 08 '21 at 20:34
  • Note that `$` is only octal 44, hex 24 when expressed in the ASCII charset (and all its supersets such as iso8859-15, gb18030 or UTF-8). `printf '\44\n'` will print a `$` on a large majority of POSIX systems, but certainly not all of them, and POSIX for example does not guarantee that it does. `printf '\u0024'` wherever supported should print a `$` though as that's the U+0024 character, even where its encoding is not the 0x44 byte. So would `printf '\44' | iconv -f ASCII` (more portable). – Stéphane Chazelas Jun 08 '21 at 21:37