Count field separators on each line of input file and if missing/exceeding, output filename to error file - awk

Question

I have to validate the input file, Input.txt, for proper number of field separators on each row and if even one row including the header is missing or exceeding the correct number of field separators then print the name of the file to errorfiles.txt and exit.
I have another file to use as reference for the correct number of field separators, valid.txt, then compare the number of field separators on each row of the input file with the number of field separators in the valid.txt file.
awk -F '|' '{ print NF-1; exit }' valid.txt > fscount
awk -F '|' '(NF-1) != "cat fscount" { print FILENAME>"errorfiles.txt"; exit}' Input.txt
This is not working.
awk -F '|' '{ print NF-1; exit }' valid.txt > fscount
awk -F '|' '(NF-1) != "cat fscount" { print FILENAME>"errorfiles.txt"; exit}' Input.txt

Answer 1

It is not fully clear what your requirement is, to print the FILENAME on just a single input file provided, perhaps you wanted to loop over a list of files on a directory running this command?
Anyway, to use the content of the file in the context of awk, just use its -v switch and use input re-direction on the file
awk -F '|' -v count="$(<fscount)" -v fname="errorfiles.txt" '(NF-1) != (count+0) { print FILENAME > fname; close(fname); exit}' Input.txt
Notice the use of close(filename) here, which is generally required when you are manipulating files inside awk constructs. The close() call just closes the file descriptor associated with opening the file pointed by filename explicitly, instead of letting the OS do it.

Answer 2

GNU awk solution:
awk -F '|' 'ARGIND==1{aimNF=NF; nextfile} ARGIND==2{if (NF!=aimNF) {print FILENAME > "errorfiles.txt"; exit}}' valid.txt Input.txt
You can do it with just one command,
-- use awk to read two files, store NF number of 1st file, and compare it in the second file.
For other awk you can replace ARGIND==1 with FILENAME==ARGV[1], and so on.
Or if you are sure first file won't be empty, use NR==FNR and NR>FNR instead.