I've finally gotten 'cpio' into a shape where it could be useable. This version can archive and extract directories, sockets, FIFOs, devices, symlinks, and regular files. Supported options are -iot, -H FMT (which is a dummy right now). It only writes newc, and could read newc or newcrc. This does NOT implement -d, which essentially is equivalent to mkdir -p $(dirname $FILE) for every file that needs it. Hard links are not supported, though it would be easy to add them given a hash table or something like that. I also have not implemented the "<n> blocks" output on stderr. If desired, I can add it pretty simply. There is one assumption this makes: that the mode of a file, as mode_t, is bitwise equivalent to the mode as defined for the cpio format. This is true of Linux, but is not mandated by POSIX. If it is compiled for a system where that is false, the archives will not be portable.

#!/bin/bash

[ -f testing.sh ] && . testing.sh

#testing "name" "command" "result" "infile" "stdin"

#TODO: Find better tests

testing "pwd" "[ $(stat -c %i "$(pwd)") = $(stat -c %i .) ] && echo yes" \
	"yes\n" "" ""
testing "pwd -P" "[ $(stat -c %i "$(pwd -P)") = $(stat -c %i .) ] && echo yes" \
	"yes\n" "" ""


ln -s . sym
cd sym
testing "pwd" "[ $(stat -c %i "$(pwd)") = $(stat -c %i "$PWD") ] && echo yes" \
	"yes\n" "" ""
testing "pwd -P" "[ $(stat -c %i "$(pwd -P)") = $(stat -c %i "$PWD") ] || echo yes" \
	"yes\n" "" ""
cd ..
rm sym

export PWD=walrus
testing "pwd (bad PWD)" "[ "$(pwd)" = "$(cd . ; pwd)" ] && echo yes" \
	"yes\n" "" ""