#!/bin/bash
# 0.0.1 - Initial adaptation from 
#           http://www.fsckin.com/2008/03/19/twittering-from-the-command-line/
# 0.0.2 - Protect against errors when using:
#           cl-twit "This isn't going to cause an error."
#         The double quotes are needed because of the '.
#           The quotes introduce spaces into $1, so it gets wrapped with ""
# 0.0.3 - Don't print JSON returned by twitter.com
#       - Add verbose option to report # chars used/left.
#       - Discard account and message environment variables after used.

TWITMAX=140
TWITFILE=~/.twitter
TWITFILESECURE=unknown
TWITVERBOSE=false

# Check verbose flag
if [ "x$1" == "x-v" ]; then
    TWITVERBOSE=true
    shift
fi

# Can't post an empty status
if [ -z "$1" ]; then
    echo You have to say SOMETHING!
    exit
fi

# Build message and get it's length
TWITMESSAGE=`echo $@|tr ' ' '+'`
TWITLENGTH=`echo -n $TWITMESSAGE|wc -c`

# Report characters used if being verbose
if [ $TWITVERBOSE == "true" ]; then
    echo $TWITLENGTH used, $(($TWITMAX-$TWITLENGTH)) spare
fi

# Don't post if it's just going to get truncated
if [ $TWITLENGTH -gt $TWITMAX ]; then
    echo "Message is too long! $TWITLENGTH is over the $TWITMAX limit"
    exit
fi

# Is the account settings file secure
if ( stat $TWITFILE | grep '^Access: (..00/' > /dev/null ) ; then
    TWITFILESECURE=yes
fi

# Don't let anything work if we aren't secure
if [ $TWITFILESECURE != "yes" ]; then
    echo The file $TWITFILE should not be world readable
    echo Try: chmod go-rwx $TWITFILE
    exit
fi

# Load account settings
. $TWITFILE

# Username is a mandatory setting
if [ -z $TWITUSER ]; then
    echo TWITUSER not set in $TWITFILE
    exit
fi

# Password is a mandatory setting
if [ -z $TWITPASS ]; then
    echo TWITPASS not set in $TWITFILE
    exit
fi

# Dispatch message to twitter
curl --basic --user "$TWITUSER:$TWITPASS" \
    --data-ascii "status=$TWITMESSAGE" \
    --silent "http://twitter.com/statuses/update.json"

# Paranoia
# I don't know that these could be recovered, but you never know.
unset TWITUSER TWITPASS TWITMESSAGE