Splits a fixedStep .wig file at its headers

splitter.sh

#!/bin/bash
## BASED ON : https://www.baeldung.com/linux/split-file-at-line-numbers
INPUT_FILE="out/experimental_reads.wig"  # The input file
LINE_NUMBERS=( $(cat $INPUT_FILE | grep -n "g" | cut -f 1 -d":"  | tr '\n' ' ') ) # The given line numbers (array)
START=1                 # The offset to calculate lines
IDX=1                   # The index used in the name of generated files: file1, file2 ...

for i in "${LINE_NUMBERS[@]}"
do
    # Extract the lines using the head and tail commands
    tail -n +$START "$INPUT_FILE" | head -n $(( i-START+1 )) > "file$IDX.txt"
    (( IDX++ ))
    START=$(( i ))
done
# Extract the last given line - last line in the file
tail -n +$START "$INPUT_FILE" > "file$IDX.txt"