I ended up writing a script because it seems there is no solution on the net:

 #!/bin/bash
 
 CMD=$1
 #DIR=$(readlink -ve "/proc/$PPID/cwd")
 DIR=`pwd`
 PRIVILEGE='$'
 
 #echo $DIR
 
 if [ $UID -ne 0 ]; then echo "Please run this script with sudo:"; echo "sudo $0 $*"; exit 1; fi
 
 mkdir -p /result
 
 #echo $DIR
 PATTERN="^\/home\/\w+$"
 if [[ $DIR =~ $PATTERN ]] || [ $DIR == '/root' ]; then DIR='~'; else DIR=`basename $PWD`; fi
 echo $DIR
 
 if [ $UID -eq 0 ]; then PRIVILEGE='#'; fi
 #echo $PRIVILEGE
 
 NUM=`ls -vr /result/ | head -1 | sed 's/.png//'`
 if [ ! -n "$NUM" ]; then NUM=1; else ((NUM++)); fi
 
 convert -font DejaVu-Sans-Mono-Book -pointsize 16 label:"$(echo "[`id -u -n`@`hostname` $DIR]$PRIVILEGE $CMD";$CMD)" /result/$NUM.png
 echo $NUM.png

edit: improved script to make it more generalized.