Q:

How to make hexdump not wait for 16 characters from stdin to display their hex values?

If I opened hexdump without any argument in the terminal:
hexdump

When I type something in the terminal and press Enter, hexdump will display the hex values for whatever characters I type.
But hexdump will only display the hex values if I type 16 characters, for example:

Here, I typed the character a 15 times and I pressed Enter(so hexdump received 16 characters (15a + \n)).
But if I type less than 16 characters, for example:

Here, I typed the character a 14 times and I pressed Enter(so hexdump received 15 characters (14a + \n)). And in this case hexdump did not display anything.
Can I make hexdump display the hex values for whatever length of characters it receives instead of it waiting for 16 characters to be received?
Note: I do not want to "use options both for hexdump and xxd to display one byte as hex per line" (as suggested in a comment here). What I want to do basically is for example to know what the hex value for A without having to type an extra 15 characters to get it.

A:

Try hexdump -v -e '/1 "%02X\n"'. That displays one hex byte per line, so the line output buffering won't stop the line from being displayed.
Then you only have to type A and return to know the hex value for A. You still have to type return, because the shell buffers also does line buffering on the input.
man ascii also works. :-)

