doi2bib

#!/bin/bash
#
# usage:
#   doi2bib -d DOI | -i DOILISTFILE [-o OUTBIBFILE]
#
# arguments:
#   -d DOI: doi URL reference e.g.,
#           http://dx.doi.org/10.1002/2014GL062882 or simply
#           10.1002/2014GL062882
#
#   -i DOILISTFILE: A text file containing doi lists of multiple references
#           Note: Use either -d or -i option
#
#   -o OUTBIBFILE (optional): Filename to write bibtex entries, default is
#           screen-dump
#
# requires:
#   cURL
#
# author:  yaswant.pradhan 2015-08-26
# Reference: http://crosscite.org/cn/
# -----------------------------------------------------------------------------

# usage -----------------------------------------------------------------------
usage() {
cat <<EOF

Usage:
    $(basename $0) -d DOI | -i DOILISTFILE [-o OUTBIBFILE]
EOF
}

# Parse command line arguments -----------------------------------------------------
while [ ! -z "$1" ]; do
    if [ -z "$2" ]; then
        echo "Input option ($1) requires a parameter."
        exit 1
    fi

    case $1 in
        "-d") DOI=$2; shift ;;
        "-i") DOILISTFILE=$2; shift ;;
        "-o") OUTBIBFILE=$2; shift ;;
        *) echo "Did not recognise input ($1)."; exit 1;;
    esac
    shift
done

# Check arguments:
[ -z "$DOI" ] && [ -z "$DOILISTFILE" ] && { usage && exit ; }

# Check conflicting options:
[ ! -z "$DOI" ] && [ ! -z "$DOILISTFILE" ] && \
{ echo "Conflicting options [-d|-i]"; usage && exit ; }

# Construct doi array:
[ -f "$DOILISTFILE" ] && dois=( $(cat "$DOILISTFILE") ) || dois=$DOI


# Retrieve entries ------------------------------------------------------------
echo -e "Retrieving ${#dois[@]} entrie(s)..\n"
base_url='http://dx.doi.org'
cnt=1
for doi in ${dois[@]}; do
    [[ $doi != $base_url* ]] && doi=$base_url/$doi
    if [ -z "$OUTBIBFILE" ]; then
        curl -LH "Accept: text/bibliography; style=bibtex" $doi
        echo
    else
        [[ $cnt -eq 1 ]] && echo > "$OUTBIBFILE" || echo >> "$OUTBIBFILE"
        curl -sLH "Accept: text/bibliography; style=bibtex" $doi >> "$OUTBIBFILE"
    fi
    cnt=$(( cnt+1 ))
done