On my machine I get the following output when I run these commands:
$ echo foos > myfile
$ hexdump myfile
6f66 736f 000a
The output from hexdump is little-endian. Does this mean that my machine is little-endian, or does hexdump always use little-endian format?
Yes, the traditional BSD hexdump utility always uses the platform's endianness. Use hexdump -C (or od -t x1) to get more sensible byte-by-byte output.
From the manpage:
-x Two-byte hexadecimal display. Display the input offset in hexa‐
decimal, followed by eight, space separated, four column, zero-
filled, two-byte quantities of input data, in hexadecimal, per
line.
...
If no format strings are specified, the default display is equivalent to
specifying the -x option.
Your output is little-endian (least significant byte first), which is also the endianness of the x86 and x86_64 architectures, which you are probably using.
