Scrutinizer, MadeInGermany, and wisecracker touched on some problems in your script, but there are other problems here.

Code:

WTHP=`echo "$file" | cut -c158-162`

does not return the 158th through the 162nd byte from the 1st line in the file named by the expansion of the file shell variable; it returns that range of characters (not bytes) in the name (not the contents) of the file.

From your description it is not at all clear what you want to do with the above line. If you want the 158th through the 162nd bytes from the contents of the file, that would be something like:

Code:

WTHP=$(dd if="$file" bs=1 skip=157 count=5)

If you want the 158th through the 162nd bytes from the 1st line of the contents of the file, that would be something like:

Code:

WTHP=$(head -n 1 "$file"|cut -b158-162)

If you want the 158th through the 162nd bytes from every line of the contents of the file, that would be something like:

Code:

WTHP=$(cut -b158-162 "$file")

It isn't clear what you're trying to check with:

Code:

if [[ $WTHP = " " ]]

but it isn't likely to be what you want. You talk about 5 bytes being an empty string, but by definition an empty string only contains a single string terminating null character. If you want to verify that $WTHP expands to 5 space characters, that should be:

Code:

if [ "$WTHP" = "     " ]
      or
if [[ "$WTHP" == "     " ]]

And, the code:

Code:

WTHP=0
echo "$WTHP=" $WTHP >> $Log

will append the line:

Code:

0= 0

to the file named by the expansion of $Log. If you wanted to append:

Code:

$WTHP=0

to your log file, that would be something like:

Code:

echo '$'"WTHP=$WTHP" >> "$Log"