Shell Programming and Scripting

$ echo "'" "''" "'''"
' '' '''

$ echo '"' '""' '"""'
" "" """

$ echo '"'"'" "'"'"'
"' '"

#! /bin/bash
##################################################################################
#  tmail: Send an Email with Telnet v0.5                                         #
##################################################################################
#  Michael E. Stora, July 2014
##################################################################################
#  Declarations                                                                  #
##################################################################################
header="%%%%%"
boundary="$(read -r -n 512 line </dev/urandom; echo $line | sha256sum)"
warning="This is a multipart message in MIME format."
host="$HOSTNAME"
sender="$USER""@""$HOSTNAME"
mailDate="$(date +%a", "%d" "%b" "%Y" "%T" "%z)"
##################################################################################
# Standard User Editable Defaults
# move this to a .conf file later               <<<<<<<<<<<< To Do
subject="no subject"
server="smtp.xxxxx.com"; port="25"; delay="1"
##################################################################################
#
# Add usage function and help <<<<<<<<<<<< To Do
#
declare -A recipients   # We are going to use associative array keys (and not values)
declare -A toList       # to keep track of mailing lists ${!array[@]} as a builtin
declare -A ccList       # way of preventing duplicates without sorting.
#
# add getopts options to handle "-x" type arguments.   <<<<<<<<<<<< To Do
#
# grab remaining arguments (parse remaining $@ into newline delimited commands list) <<<<<<<<<<<< To Do
#
# read in commands from stdin between "$header" lines, if any
read -r line
if [[ "$line" == "$header" ]]; then
    while read line && [[ "$line" != "$header" ]]; do commands+="$line"$'\n'; done
else
    firstLine="$line" # Oops! Not a header afterall.  Manaully add it to top of body later.
fi
#
# Process commands from whatever source (options, arguments, body header)
# usage: command:value1{:value2:value3}
numA=-1 # attachment numbering starts at 0
oIFS="$IFS"; IFS=$'\n'; for var in $commands; do
    if [[ "$var" == *:* ]]; then # does it look like a command or a naked email?
        IFS=":" read -r comm val1 val2 val3 < <(echo "$var") # using named FIFO instead of pipe to
                                                             # keep read variables in the current shell.
        case "${comm,,}" in # usage: match lowercase version of comm
            "subject"|"s") subject="$val1" ;;
            "from"|"f") sender="$val1" ;;
            "to"|"t") recipients["$val1"]=1; toList["$val1"]=1 ;;
            "cc"|"c") recipients["$val1"]=1; ccList["$val1"]=1 ;;
            "bcc"|"b") recipients["$val1"]=1 ;;
            "attach"|"a") # usage: attach:att_path:att_MIME_type(optional):att_name(optional)
                attachment[$((++numA))]="$val1"
                attachmentType[numA]="$val2"
                [[ "$val3" ]] && attachmentName[numA]="$val3" || attachmentName[numA]="${val1##*/}"
                # if no name given, default to short filename from path
                # add code for guessing MIME type from file extension if blank  <<<<<<<<<<<< To Do
                ;;
            "server") # usage: server(optional):server:port(optional):delay(optional)
                [[ "$val1" ]] && server="$val1"
                [[ "$val2" ]] && port="$val2"
                [[ "$val3" ]] && delay="$val3"
                ;;
            "port") port="$val1" ;;
            "delay") delay="$val1" ;;
            "host") host="$val1" ;;
            "boundary") boundary="$val1" ;;
            "warning") warning="$val1" ;;
            "date") mailDate="$val1" ;;
            *) echo "bad command"; exit 1 ;;  #add usage/help here. <<<<<<<<<<<< To Do
        esac
    else recipients["$var"]=1; [[ ! "$blind" ]] && toList["$var"]=1
    # naked email addresses are To: unless blind is set (then BCC:)
    fi
done; IFS="$oIFS"
#
# Telnet Session
{   echo "HELO ""$host"
    sleep "$delay"
    echo "MAIL FROM: ""$sender"
    sleep "$delay"
    oIFS="$IFS"; IFS=$'\n'; for i in "${!recipients[@]}"; do
        echo "RCPT TO: ""$i"
        sleep "$delay"
    done; IFS="$oIFS"
    echo "DATA"
    sleep "$delay"
    echo "From: ""$sender"
    toString="To: "
    oIFS="$IFS"; IFS=$'\n'; for i in "${!toList[@]}"; do
        toString+="$i"", "; done; IFS="$oIFS" # comma+space delimited
    echo "${toString%, }" # remove last comma+spave
    ccString="CC: "
    oIFS="$IFS"; IFS=$'\n'; for i in "${!ccList[@]}"; do ccString+="$i"", "; done; IFS="$oIFS"
    echo "${ccString%, }"
    echo "Date: ""$mailDate"
    echo "Subject: ""$subject"
    echo "Content-Type: multipart/mixed; boundary=\"""$boundary""\""
    echo "MIME-Version: 1.0"
    echo
    echo "$warning"
    echo
    echo "--""$boundary"
    echo "Content-Type: text/plain"
    echo
    if [[ "$firstLine" ]]; then echo "$firstLine"; fi
        while read line && [[ "$line" != "$header" ]]; do echo "$line"; done
    echo
    for i in `seq 0 "$numA"`; do
        echo "--""$boundary"
        echo "Content-Type: ""{$attachmentType[$i]}""; name=\"""${attachmentName[$i]}""\""
        echo "Content-Transfer-Encoding: base64";
        echo "Content-Disposition: attachment; filename=\"""${attachmentName[$i]}""\""
        echo
        base64 <"${attachment[$i]}"
        echo
    done
    echo "--""$boundary""--"
    echo "."
    sleep "$delay"
    echo "QUIT"; } | telnet "$server" "$port"
#
exit 0

function quoted_read
{
  typeset lInStr=0
  typeset chBuffer
  typeset chAct
  typeset PrevWS=1

  [ $# -eq 0 ] && set -- REPLY

  OIFS=$IFS
  IFS=
  while read -N 1 -r chAct
  do
     case "$chAct" in
        \") (( lInStr = (lInStr + 1) % 2 ))
             continue
            ;;
        \\) read -N 1 chAct ;;
        " "|$'\n'|$'\t')
             if [ $lInStr -eq 0 ]
             then
                 [ "$chAct" == $'\n' ] && break
                 [ $PrevWS -ne 0 ] && continue
                 if [ $# -gt 1 ]
                 then
                    # More vars to assign -> not appending to current
                    export $1="$chBuffer"
                    shift
                    chBuffer=""
                    PrevWS=1
                    continue
                 fi
             fi
             ;;
        *) PrevWS=0 ;;
     esac
     chBuffer="${chBuffer}${chAct}"
  done

  export $1="$chBuffer"
  shift

  # Blank any vars not assigned
  while [ $# -gt 0 ]
  do
      export $1=""
      shift
  done
  IFS=$OIFS
  [ "$chAct" == $'\n' ]
}

boundary="$(openssl rand -hex 32)"

      " ")
          if [ -n "$chBuffer" ] ; then
               # output/process the buffer which just ended
          else
               # do nothing
          fi
          ;;