Command-line to reverse byte order/change endianess

Question

I\'m hacking around in some scripts trying to parse some data written by Javas DataOutputStream#writeLong(...). Since java always seems to write big endian, I have

Answer 1

I came up with this Perl one-liner to convert 4-byte integers from one endianness to another:

$ perl -e 'open F,shift; do { read(F,$a,4); print scalar reverse($a);} while(!eof(F));' bigend.bin > littlend.bin

That probably works fine on real Linux machines, but Cygwin bit me in the end, treating the binary file as text and inserting a 0x0D (aka CR) before each 0x0A byte (aka newline). But if you pipe to cat -, it seems to leave it alone. This works for me:

$ perl -e 'open F,shift; do { read(F,$a,4); print scalar reverse($a);} while(!eof(F));' bigend.bin | cat - > littlend.bin