x
s/$/=/
:0
s/^=/1/
s/=/=0123456789=0 /
s/\(.\)=.*\1\(=*.\).* /\2/
t0
G
s/\(.*\)\n\(.*\)/\1 \2@\1/
:1
s/.\{,40\} /&!/
h
s/$/>\x09\x09\x09\x09\x09/
s/\x09/\x09\x09\x09\x09\x09\x09\x09\x09/g
:2
s/!.*>\| \|\S\x09//
t2
G
h
s/[^ ]\| !.*//g
y/ /\x09/
G
s/ !.*//
:3
s/\(\n\(\x09*\).*\) /\1\2/
t3
s/\n\x09*//
:
s/^\(\(\x09*\)\n[^\x09]*\)\2/\1 /
t
s/\x09\(\S\)/\1\x09/
t
s/.*\n//p
g
s/.* !//
/.\{41\}@/b1
h
s/.*@//
x
s/@.*//
Note that non-ascii characters in the above source code will be escaped (such as \x9f).