$/=\108;
($/) = (<> =~ /^.{105}(.?\r?\n?)/);
seek ARGV, 0, 0;

##</code><code>##

# Look ahead into the file for the ISA segment and the few characters which
#	follow it, so that we can determine the segment terminator character(s).
$/ = \108;
my $ISA_and_trailing_chars = <>;

# examine the text after the segment for the segment termination character(s)
$ISA_and_trailing_chars =~ /
	^.{105}		# The actual ISA segment, itself
	(
		.?		# The proper segment terminator character
		\r?		# If the segment terminator is followed by a newline and/or
		\n?		#	carriage return, include that as part of the segment
				#	terminator.  this isn't really legal to do, but some
				#	folks do it, regardless, and we want to be able to handle
				#	that sort of garbage as though it weren't garbage.
	)
/x;
my $segment_terminator = $1;

# set the input record separator to the segment termination character(s), so
#	that subsequent reads from the file will read one segment at a time.
$/ = $segment_terminator;

# since we peeked ahead into the file, to determine *how* to read it, now
#	seek back to the beginning of it, so that we can read it (all) correctly
seek ARGV, 0, 0;

##</code><code>##

#!/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" directives,
                -M*)    ;; # "n"s in them should be ignored
                -*n*)   looptype=n;;
                -h)             echo 'x12cat: "magic" x12 spooler wrapper around command-line perl.
  -splits files by segment terminator
  -auto sets $f and $c to (regex-escaped) field and component separators
  -auto sets the autosplit to the field separator (for the -a autosplit)
  -allows -pe or -ne operations on file (or none at all to just cat the file)'; exit;;
                -*)             ;;
                *)              break;;
        esac
done
if [ "x$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"); seek ARGV,0,0; $.=0}' -F'/$f/' "$@"

##</code><code>##

$ x12cat -ne 'print if /^GS/' some_file.x12

##</code><code>##

$ x12cat -ane '$paid += $F[4] if $F[0] eq "CLP"; END{print $paid}' some_835_file.x12

##</code><code>##

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:Wq
Not an editor command: Wq