#!/usr/bin/env sh

# @(#) s1       Demonstrate extraction of range to separate files.

#  ____
# /
# |   Infrastructure BEGIN

echo
set -o nounset

debug=":"
debug="echo"

## The shebang using "env" line is designed for portability. For
#  higher security, use:
#
#  #!/bin/sh -

## Use local command version for the commands in this demonstration.

set +o nounset
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version =o $(_eat $0 $1) awk my-nl
set -o nounset

# Use nawk or /usr/xpg4/bin/awk on Solaris.

echo

FILE=${1-data1}
echo " Input file $FILE:"
cat $FILE

# |   Infrastructure END
# \
#  ---

echo
echo " Results from processing:"
awk '
BEGIN   { i = 0 }
/ST/            { i++ ; name = "file" i }
/ST/,/SE/       { print > name }
' $FILE

my-nl file?

exit 0

% ./s1

(Versions displayed with local utility "version")
Linux 2.6.11-x1
GNU bash, version 2.05b.0(1)-release (i386-pc-linux-gnu)
GNU Awk 3.1.4
my-nl (local) 296

 Input file data1:
ST
first invoice
SE
ST
second invoice
SE
ST
third invoice
SE

 Results from processing:

==> file1 <==

  1 ST
  2 first invoice
  3 SE

==> file2 <==

  1 ST
  2 second invoice
  3 SE

==> file3 <==

  1 ST
  2 third invoice
  3 SE