China DOS Union

-------------------------------
1.test
are
yes
god!
no
pre
love/
***
123

-------------------------------
2.text
want
go
do
is

Example 3.text
arewantyesgod!noprelove/***123
areyeswantgod!noprelove/***123
areyesgod!wantnoprelove/***123
areyesgod!nowantprelove/***123
areyesgod!noprewantlove/***123
areyesgod!noprelove/want***123
areyesgod!noprelove/***want123
areyesgod!noprelove/***123want
areyeswantgod!noprelove/***123
arewantyesgod!noprelove/***123
arewantgod!yesnoprelove/***123
arewantgod!noyesprelove/***123
arewantgod!nopreyeslove/***123
arewantgod!noprelove/yes***123
arewantgod!noprelove/***yes123
arewantgod!noprelove/***123yes
....

Randomly combine each line string in 1.text, and at the same time combine with each line of 2.text to form a new line and write to 3.text. Each line in 3.text cannot be repeated

(Please note)
2.text may have tens of thousands of lines
1.text may have tens of thousands of lines

Under the MS-DOS system?

Support, friends, help each other, thank you

Your requirement for randomness is still unclear.
"Randomly combine each line of strings in 1.text", how many to combine? Also randomly several?
"Combine with each line of 2.text to form a new line", which position of the new line is the string of the combined line of 2.text? Also random?

What is this used for?

I. "Randomly combine each line of strings in 1.text", how many to combine? Also randomly how many?
If 1.text has m lines, randomly combine m lines
II. The line of strings combined in 2.text
2.text has n lines, extract each line in order, cycle and combine with each new line after random in 1.text in order to generate 2.text
n must be much smaller than m

Passing by, I never use pure DOS systems...