old school cats

[Russ]

Cat without sed is kind of like pancakes without syrup in a POSIX manner of compliance.

Some unix components are hardwired to do one thing and do it as well as possible.

Neither cat nor sed are interactive as ed is. With line based editing you are allowed to

g/re/p

on a file in order to TRanslate from one format to another.

Ghostscript can do it but is lossy as mentioned.

Example from the internet.

gs -q -sPAPERSIZE=letter - dNOPAUSE -dBATCH- sDEVICE=pdfwrite - sOutputFile=out.pdf

  Heck, you could tac the file use dd to skip the eof bytes, tac it again and see what happens.

But you cannot under normal circumstances cat file1 file2>file2. No responsible sysadmin will allow it regardless of POSIX standard.

UNIX is a set of student hacks glued together by god knows what, but there seems to be enough wiggle room for everybody.