How to split one text file into multiple *.txt files?

Question

I got a text file file.txt(12 MBs) containing:

something1
something2
something3
something4
(...)

Is there any way to split

Answer 1

Using bash:

readarray -t LINES < file.txt
COUNT=${#LINES[@]}
for I in "${!LINES[@]}"; do
    INDEX=$(( (I * 12 - 1) / COUNT + 1 ))
    echo "${LINES[I]}" >> "file${INDEX}.txt"
done

Using awk:

awk '{
    a[NR] = $0
}
END {
    for (i = 1; i in a; ++i) {
        x = (i * 12 - 1) / NR + 1
        sub(/\..*$/, "", x)
        print a[i] > "file" x ".txt"
    }
}' file.txt

Unlike split this one makes sure that number of lines are most even.