#!/bin/awk --file

# File   : bib2aux.awk 
# Descr  : extract all keys from a bib file into an aux file which then
#          can be processed with bibtex to generate a formatted listing of all
#          bib entries
# Author : Andreas Abel
# Created: 2005-10-13

# We only treat entries of a bib-file which start with a line
#
#   @  <type>  {  <key>  ,
#
# and write the key into the output as
#
#   \citation{<key>}
#
# We can safely assume that all bib-entries follow the above convention,
# although I am not sure whether the <key> has be to on the same line as 
# the <type>.
#
# Following Gerd Neubauer's documentation for bibtool, a key might not
# contain whitespaces and any of
#
#   " # % ' ( ) , = { }

BEGIN {
  printf ("% Created by bib2aux.awk\n");
  FS = "[ \t{,]+";  # treat { and , as field separators plus whitespaces
}

/\@.+\{.+,/ {
  printf ("\\citation{%s}\n", $2);
}

# The matching idea did not work, it seems that awk does not support 
#   the emacs-style bracketing \(...\) and \1,\2 ...

# TRASH:
#  printf ("1%s2%s3%s4%s5", $1, $2, $3, $4, $5) ;
#  if ( $0 ~ /\(.+\)/ ) {  
#  if ( $0 ~ /[ \t\n]*[@].+\{\(.+\),/ ) {
#  if ($0 ~ /[ \t\n]*\@.+\{[ \t\n]*\([^ \n\t"#%'(),={}]+\){[ \t\n]*,/) {
#    printf ("\\citation{%s}\n", $1);
#  }