#!/usr/bin/env bash # # by Siddharth Dushantha 2020 # # Dependencies: jq, curl, w3m # export LC_CTYPE=C export LANG=C VERSION=1.0.0 # By default 'tmpmail' uses 'w3m' as it's web browser to render # the HTML of the email BROWSER="w3m" # If the value is set to 'true' tmpmail will convert the HTML email # to raw text and send that to stdout RAW_TEXT=false # Everything related to 'tmpmail' will be stored in /tmp/tmpmail # so that the old emails and email addresses get cleared after # restarting the computer TMPMAIL_DIR="/tmp/tmpmail/" # TMPMAIL_EMAIL_ADDRESS is where we store the temporary email address # that gets generated. This prevents the user from providing # the email address everytime they run tmpmail TMPMAIL_EMAIL_ADDRESS="$TMPMAIL_DIR/email_address" TMPMAIL_HTML_EMAIL="$TMPMAIL_DIR/tmpmail.html" usage(){ # Using 'cat << EOF' we can easily output a multiline text. This is much # better than using 'echo' for each line or using '\n' to create a new line. cat << EOF usage: tmpmail [-h] [--generate] [--browser BROWSER] [--recent] ID optional arguments: -h, --help Show this help message --version Print version -g, --generate Generate a new email address -r, --recent View the most recent email -t, --text View the email as raw text, where all the HTML tags are removed -b, --browser Change the browser that is used to render the HTML of the email (default: w3m) EOF } generate_email_address(){ # There are 2 ways which this function is called in this script. # [1] The user wants to generate a new email and runs 'tmpmail --generate' # [2] The user runs 'tmpmail' to check the inbox , but /tmp/tmpmail/email_address # is empty or nonexistant. Therefore a new email gets automatically # generated before showing the inbox. But of course the inbox will # be empty as the newly generated email address has not been # sent any emails. # # When the function 'generate_email()' is called with the arguement # 'true', it means that the function was called because the user # ran 'tmpmail --generate'. # # We need this variable so we can know whether or not we need to show the user # what the email was. <-- More about this can be found further down in this function. EXTERNALLY=${1:-false} # Generate a random email address. # This function is called whenever the user wants to generate a new email # address by running 'tmpmail --generate' or when the user runs 'tmpmail' # but /tmp/tmpmail/email_address is empty or nonexistent. # # We create a random username by taking the first 10 lines from /dev/random # and delete all the characters which are *not* lower case letters from A to Z. # So charcters such as dashes, periods, underscore, and numbers are all deleted, # giving us a text which only contains lower case letters form A to Z. We then take # the first 10 characters, which will be the username of the email address USERNAME=$(head /dev/urandom | tr -dc a-z | cut -c1-11) # This is an array of the valid TLDS which 1secmail provides. TLDS=(com net org) # Randomly pick one of the TLDS mentiond above. # This is done by first echoing all the TLDS into 'tr' which then # replaces the white spaces with a new line. This is done because we use # 'sort' to put the TLDS in a random order, but 'sort' requires the TLDS to # be on seperate lines. After the randomizing is done we take the first line # which is one of the TLDS TLD=$(echo "${TLDS[@]}" | tr " " "\n" | sort -R | head -n 1) # Save the generated email address to the $TMPMAIL_EMAIL_ADDRESS file # so that it can be whenever 'tmpmail' is run echo "$USERNAME@1secmail.$TLD" > "$TMPMAIL_EMAIL_ADDRESS" # If this function was called because the user wanted to generate a new # email address, show them the email address [ "$EXTERNALLY" = true ] && cat "$TMPMAIL_EMAIL_ADDRESS" } get_email_address(){ # This function is only called once and that is when this script # get executed. The output of this function gets stored in $EMAIL_ADDRESS # # If the file that contains the email address is empty, # that means we do not have an email address, so generate one. [ ! -s "$TMPMAIL_EMAIL_ADDRESS" ] && generate_email_address # Output the email address by getting the first line of $TMPMAIL_EMAIL head -n 1 "$TMPMAIL_EMAIL_ADDRESS" } list_emails(){ # List all the received emails in a nicely formatted order # # Fetch the email data using 1secmail's API DATA=$(curl -sL "http://1secmail.$TLD/api/v1/?action=getMessages&login=$USERNAME&domain=1secmail.$TLD") # Using 'jq' we get the length of the JSON data. From this we can determine whether or not # the email address has gotten any emails DATA_LENGTH=$(jq length <<< "$DATA") # We are showing what email address is currently being used # in case the user has forgotten what the email address was. echo -e "[ Inbox for $EMAIL_ADDRESS ]\n" # If the length of the data we got is 0, that means the email address # has not received any emails yet. [ "$DATA_LENGTH" -eq 0 ] && echo "No new mail" && exit # This is where we store all of our emails, which is then # displayed using 'column' INBOX="" # This for loop goes through each mail that have been received. # # Since we need to go through all the data, we need to tell our for loop # to loop from 1 to X, where X is legnth of the $DATA which contains all # the emails. # # Normally to loop from 1 to 5, we would use shell expansion and write: # for index in {1..5}; do # do_something # done # # But we a minor issue. We dont know what the final number is, and we are not allowed # use to variables in shell expansions like this: # {1..$X} # # where $X is the length of the $DATA. # # To fix this issue, we can use 'seq' which will allow us to create a sequence # from X to Y. # Example: # $ seq 1 5 # 1 # 2 # 3 # 4 # 5 # # We can then put those results into the foor loop for index in $(seq 1 "$DATA_LENGTH"); do # Since arrays in JSON data start at 0, we must subtract # the value of $index by 1 so that we dont miss one of the # emails in the array MAIL_DATA=$(jq -r ".[$index-1]" <<< "$DATA") ID=$(jq -r ".id" <<< "$MAIL_DATA") FROM=$(jq -r ".from" <<< "$MAIL_DATA") SUBJECT=$(jq -r ".subject" <<< "$MAIL_DATA") # The '||' are used as a divideder for 'column'. 'column' will use this divider as # a point of reference to create the division. By default 'column' uses a blank space # but that would not work in our case as the email subject could have multiple white spaces # and 'column' would split the words that are seperated by white space, in different columns. # # Yes, there a double quote all by it self on the line under this one. # This serves as a new line. So that the 'column' command works properly. # I know I could have used '\n' but 'column' does not intepret it as a new line. INBOX+="$ID ||$FROM ||$SUBJECT " done # Show the emails cleanly column -t -s "||" <<< "$INBOX" } view_email(){ # View an email by providing it's ID # # The first argument provided to this function will be the ID of the email # that has been received EMAIL_ID="$1" DATA=$(curl -sL "http://www.1secmail.$TLD/api/v1/?action=readMessage&login=$USERNAME&domain=1secmail.$TLD&id=$EMAIL_ID") # After the data is retrieved using the API, we have to check if we got any emails. # Luckly 1secmail's API is not complicated and returns 'Message not found' as plain text # if our email address as not received any emails. # If we the error message from the API just quit because there is nothing to do [[ "$DATA" == "Message not found" ]] && echo "Message not found" && exit 1 # We pass the $DATA to 'jq' which extracts the values FROM=$(jq -r ".from" <<< "$DATA") SUBJECT=$(jq -r ".subject" <<< "$DATA") HTML_BODY=$(jq -r ".htmlBody" <<< "$DATA") # Create the HTML with all the information that is relevant and then # assigning that HTML to the variable HTML_MAIL. This is the best method # to create a multiline variable read -r -d '' HTML_MAIL << EOF 
To: $EMAIL_ADDRESS
From: $FROM
Subject: $SUBJECT
$HTML_BODY EOF # Save the $HTML_MAIL into $TMPMAIL_HTML_EMAIL echo "$HTML_MAIL" > "$TMPMAIL_HTML_EMAIL" # If the '--text' flag is used, then use 'w3m' to convert the HTML of # the email to pure text by removing all the HTML tags [ "$RAW_TEXT" = true ] && w3m -dump "$TMPMAIL_HTML_EMAIL" && exit # Open up the HTML file using $BROWSER. By default, # this will be 'w3m'. $BROWSER "$TMPMAIL_HTML_EMAIL" } view_recent_email(){ # View the most recent email. # # This is done by listing all the received email like you # normally see on the terminal when running 'tmpmail'. # We then use 'awk' to grab the ID of the most recent # email, which the first line. MAIL_ID=$(list_emails | awk 'NR==3{print $1}') view_email "$MAIL_ID" } main(){ # Iterate of the array of dependencies and check if the user has them installed dependencies=(jq w3m curl) for dependency in "${dependencies[@]}"; do type -p "$dependency" &>/dev/null || { echo "error: Could not find '${dependency}', is it installed?" >&2 exit 1 } done # Create the $TMPMAIL_DIR directory and dont throw any errors # if it already exists mkdir -p "$TMPMAIL_DIR" # Get the email address and save the value to the EMAIL_ADDRESS variable EMAIL_ADDRESS="$(get_email_address)" # ${VAR#PATTERN} Removes shortest match of pattern from start of a string. # In this case, it takes the EMAIL_ADDRESS and removed everything after # the '@' symbol which gives us the username. USERNAME=${EMAIL_ADDRESS%@*} # ${VAR%PATTERN} Remove shortest match of pattern from end of a string. # In this case, it takes the EMAIL_ADDRESS and removes everything until the # period '.' which gives us the TLD TLD=${EMAIL_ADDRESS#*.} # If no arguments are provided just the emails [[ $# -eq 0 ]] && list_emails && exit while [[ "$1" ]]; do case "$1" in --help|-h) usage && exit ;; --generate|-g) generate_email_address true && exit;; --browser|-b) BROWSER="$2" ;; --text|-t) RAW_TEXT=true ;; --version) echo "$VERSION" && exit;; --recent|-r) view_recent_email && exit;; # If the user provides number as an argument, # assume its the ID of an email and try getting # the email that belongs to the ID *[0-9]*) view_email "$1" && exit;; -*) echo "error: option $1 does not exist" esac shift done } main "$@"