A script to refresh the password in SIGARRA when expiring.

SIGARRA_refresh_pass

#!/bin/bash

[[ $# != 2 ]] && echo "Usage: $0 <user> <pass>" && exit 1

USER=$1
CURRENT_PASS=$2
ORIGINAL_PASS=$2
CYCLES=5
URL="https://sigarra.up.pt/feup/pt/pass_cica.muda"

function do_params() {
    USERNAME=$1
    OLD=$2
    NEW=$3
    RET="pv_sistema=S"
    RET=$RET"&pv_util=$USERNAME"
    RET=$RET"&pv_anpc=$OLD"
    RET=$RET"&pv_nopc=$NEW"
    RET=$RET"&pv_cnpc=$NEW"
    echo $RET
}


for ((i=1; i<=CYCLES; i++)); do
    NEW_PASS="$ORIGINAL_PASS"$i
    POST=`do_params $USER "$CURRENT_PASS" "$NEW_PASS"`
    echo "Setting new pass = '$NEW_PASS'"
    echo $POST
    curl -s --data $POST $URL | grep "<title>"
    CURRENT_PASS="$NEW_PASS"
    echo "Sleeping...."
    sleep 60
done

POST=`do_params $USER "$CURRENT_PASS" "$ORIGINAL_PASS"`
curl -s --data $POST $URL | grep "<title>"

This script does not check whether or not the requests succeed.
One must check the output and see where the request first failed and keep track of the last password used.