Eu queria receber esses avatares do Skype também, então usei a resposta do whitequark para fazer um pequeno script que faz exatamente isso. Aqui está:
#!/bin/bash if [ \( $# -lt 1 \) ]; then echo "Usage: $0 folder"; echo "Where folder is of the form /home/username/.Skype/username"; exit; fi; for i in 'ls $1'; do if [ -f $1/$i ]; then #echo "i: $i"; filedump='hexdump -v -e '"" 1/1 "%02x" ""' $1/$i | sed -e 's/ffd8ffe0/\nffd8ffe0/g''; nocc='echo "$filedump" | wc -l'; # occurences of the \n char. Means that there are nocc-1 occurences of our word #echo "nocc: $nocc"; if [ "$nocc" -ge 2 ]; then k=0; old_IFS=$IFS; #field separator IFS=$'\n'; offset=0; for j in $filedump; do w='echo $j | wc -m'; # gives actually lettercount+1 w=$[w-1]; offset=$[offset+w]; #echo "offset: $offset"; filename1="${i}_${k}_notclean.jpg"; filename2="${i}_${k}.jpg"; dd ibs=1 if=$1/$i of=$filename1 skip='echo "$offset/2" | bc' status=noxfer; if [ 'du $filename1 | cut -f1' -gt 0 ]; then convert $filename1 $filename2; #convert is actually only used to remove the data after the image fi; rm $filename1; k=$[k+1]; done; IFS=$old_IFS; fi; fi; done