Re: [PATCH 1/2] t5616: refactor packfile replacement

> > +# Converts bytes into their hexadecimal representation. For example,
> > +# "printf 'ab\r\n' | hex_unpack" results in '61620d0a'.
> > +hex_unpack () {
> > +	perl -e '$/ = undef; $input = <>; print unpack("H2" x length($input), $input)'
> > +}
> > +
> > +# Inserts $1 at the start of the string and every 2 characters thereafter.
> > +intersperse () {
> > +	sed 's/\(..\)/'$1'\1/g'
> > +}
> > +
> > +# Create a one-time-sed command to replace the existing packfile with $1.
> > +replace_packfile () {
> > +	# The protocol requires that the packfile be sent in sideband 1, hence
> > +	# the extra \x01 byte at the beginning.
> > +	printf "1,/packfile/!c %04x\\\\x01%s0000" \
> > +		"$(($(wc -c <$1) + 5))" \
> > +		"$(hex_unpack <$1 | intersperse '\\x')" \
> > +		>"$HTTPD_ROOT_PATH/one-time-sed"
> >  }
> 
> Urgh. This is not a problem *this* patch introduces, but why on Earth do
> we have to do complicated computations in shell code using an unholy mix
> of complex sed and Perl invocations, making things fragile and slow? We do
> have such a nice facility is the t/test-tool helper...