How to create a hex dump of file containing only the hex characters without spaces in bash?

How do I create an unmodified hex dump of a binary file in Linux using bash? The od and hexdump commands both insert spaces in the dump and this is not ideal.

Is there a way to simply write a long string with all the hex characters, minus spaces or newlines in the output?

Solution 1:

xxd -p file

Or if you want it all on a single line:

xxd -p file | tr -d '\n'

Solution 2:

Format strings can make hexdump behave exactly as you want it to (no whitespace at all, byte by byte):

hexdump -ve '1/1 "%.2x"'

1/1 means "each format is applied once and takes one byte", and "%.2x" is the actual format string, like in printf. In this case: 2-character hexadecimal number, leading zeros if shorter.

Solution 3:

It seems to depend on the details of the version of od. On OSX, use this:

od -t x1 -An file |tr -d '\n '

(That's print as type hex bytes, with no address. And whitespace deleted afterwards, of course.)