I actually built a little shell-script around it as follows:

#!/bin/sh

# since "perl -p ... -n ..." will be treated by perl as just
# "perl -p ... ..." (not allowing the -n to override the -p)
# we have to scan through any switches on the command line,
# so that commands like "x12cat -ne 'print if /^PLB/' ..."
# will work as expected... but still allow an implicit "-p"
# if no "-n" is specified.  Granted this isn't perfect...
# But this isn't so bad, because an explicit "-p" can override
# this.
looptype=""
for i do
        case "$i" in
                -m*)    ;; # -m and -M start command-line "use" direct
+ives,
                -M*)    ;; # "n"s in them should be ignored
                -*n*)   looptype=n;;
                -h)             echo 'x12cat: "magic" x12 spooler wrap
+per around command-line perl.
  -splits files by segment terminator
  -auto sets $f and $c to (regex-escaped) field and component separato
+rs
  -auto sets the autosplit to the field separator (for the -a autospli
+t)
  -allows -pe or -ne operations on file (or none at all to just cat th
+e file)'; exit;;
                -*)             ;;
                *)              break;;
        esac
done
if [ "x$looptype" = "x" ]; then
        looptype=p
fi

perl -l -$looptype -e 'BEGIN{$SIG{PIPE}="exit"; $|=1; $/=\108; ($f,$c,
+$/)=(<> =~ /^ISA(.).{100}(.)(.?\r?\n?)/); ($f,$c)=("\Q$f","\Q$c"); se
ek ARGV,0,0; $.=0}' -F'/$f/' "$@"
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x12cat -ne 'print if /^PLB/' file.x12  # grep for PLB segments
x12cat -ane '$amt{$F[1]} += $F[2] if /^AMT/; END{ print "$_: $amt{$_}"
+ for sort {$amt{$b}<=>$amt{$a}} keys %amt }' file1.x12 file2.x12 ... 
+# print sorted break down, by amount descending, of AMT code-types
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------------
:Wq
Not an editor command: Wq
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