Print unread emails from your mailbox on esc-pos compatible thermal printer

escpos-mail-printer.sh

#!/bin/bash

ICONV="ISO8859-15"
CODE_PAGE="\x1b\x74\x28"
MODE_EMPHASIS="\x1b!\x08"
MODE_NORMAL="\x1b!\x00"
CUT="\x1d\x561"
FEED_MAX="\x1b\x4a\xff"
ECHO="/usr/bin/echo -n -e"

## Debug
# CODE_PAGE="[CODE PAGE]\n"
# MODE_EMPHASIS="[B]"
# MODE_NORMAL="[N]"
# CUT="[CUT]\n"
# FEED_MAX="[FEED]\n"

unread_mail=$(echo "f*" | mail -N | grep "^[> ][NU]" | awk '{print $2}')

if [[ "$(echo "$unread_mail" | wc -l)" -eq 0 ]]; then
    exit 0
fi

for mail_num in $unread_mail; do
    if [[ "$mail_num" == "" ]]; then
        continue;
    fi

    $ECHO "$CODE_PAGE"
    $ECHO "$MODE_NORMAL"

    result=$(/usr/bin/echo -e "p$mail_num \nhold $mail_num \nq" | mail -N | tail -n+4 | head -n-1)
    
    from=$(echo "$result" | head -n 1)
    headers=$(echo "$result" | awk -v 'RS=\n\n' '1;{exit}' | tail -n+2)
    body=$(echo "$result" | tail "-n+$(($(echo "$headers" | wc -l) + 2))" )
    
    $ECHO "$MODE_EMPHASIS"
    echo "$from" | \
        iconv -f utf-8 -t $ICONV//TRANSLIT
    $ECHO "$MODE_NORMAL"
    
    echo "$headers" | \
        grep -v "Content-Type:" | \
        grep -v "MIME-Version:" | \
        grep -v "Content-Transfer-Encoding:" | \
        sed -e "s|^\([^:]*\)\(:\?\)|$MODE_EMPHASIS\1$MODE_NORMAL\2|" | \
        iconv -f utf-8 -t $ICONV//TRANSLIT
    
    echo ""
    
    echo "$body" | \
        iconv -f utf-8 -t $ICONV//TRANSLIT
    
    $ECHO "$FEED_MAX"
done