Output file with one byte per line in hex format (under linux bash)

Question

As the title says, here is an example:

$ cat test.txt 
ABCD
$ hd test.txt 
00000000  41 42 43 44 0a                                    |ABCD.|
00000005

my desired output would be:

41
42
43
44

I know that this is possible with sed, awk and stuff, but this might be very slow for large files. I thought of an format string for "hexdump" or a parameter combination for "od". Could you please help me out?

Answer 1

$ echo -n 'ABCD' | hexdump -v -e '/1 "%02x\n"'
41
42
43
44
0a

If you don't want it to print 0a at the end for the newline then I'd recommend getting rid of the newline from the file first.

Answer 2

od -An -vtx1 -w1 test.txt | cut -c2-

If you don't want newlines:

od -An -vtx1 -w1 test.txt | cut -c2- | fgrep -v 0a

Meaning of od options:

• -An : addresses: no
• -v : verbose, i.e., don't write a * instead of repeating lines
• -tx1 : output type: hex, 1 byte (use -tx1z for an hd-like output)
• -w1 : max width: 1

One nice thing about od is that it's available on any *x system.