Raggiungere la conversione
Creazione di un filesystem di prova
Al fine di preservare il nostro filesystem principale da ogni possibile danno dopo aver eseguito questo esperimento, creeremo un piccolo filesystem all'interno di un file normale a scopo di test.
Crea un file a riempimento zero chiamato testcon una dimensione di 10 megabyte:
dd if=/dev/zero of=~/test bs=10M count=1
Crea un filesystem Ext4 all'interno del file, come se fosse una partizione:
mkfs.ext4 ~/test
Creazione di alcuni file e directory
Ora abbiamo un filesystem completamente funzionale all'interno del testfile, quindi creeremo alcuni file e directory al suo interno.
Montare il filesystem appena creato all'interno /mnt:
sudo mount ~/test /mnt
Crea un file e una directory:
sudo mkdir /mnt/folder
echo "contents" | sudo tee /mnt/file
Controlla il contenuto del filesystem:
ls -l /mnt
L'output dovrebbe essere qualcosa del genere:
total 2
-rw-r--r-- 1 root root 0 may 21 18:53 file
drw-r--r-- 2 root root 1024 may 21 18:55 folder
Smonta il filesystem di prova:
sudo umount /mnt
Scambiare il file e la cartella
Esegui debugfscontro il testfile con autorizzazione di scrittura ( -wflag):
debugfs -w ~/test
Converti filein una cartella:
Al debugfsprompt, digitare questo:
modify_inode file
Apparirà un messaggio che ti chiede una modalità; digita questo:
040644
Continuare a premere returnper lasciare i dati rimanenti così come sono finché non viene di nuovo visualizzato il messaggio.
Converti folderin un file:
Al debugfsprompt, digitare questo:
modify_inode folder
Apparirà un messaggio che ti chiede una modalità; digita questo:
0100644
Continuare a premere returnper lasciare i dati rimanenti così come sono finché non viene di nuovo visualizzato il messaggio.
Per uscire dal debugfsprompt, premi semplicemente qe poireturn
Verifica del successo dell'operazione
Montare nuovamente il filesystem di prova:
sudo mount ~/test /mnt
Controlla il contenuto del filesystem:
ls -l /mnt
Ora, dovrebbe mostrare il file come se fosse una directory e viceversa :
total 2
drw-r--r-- 1 root root 0 may 21 18:53 file
-rw-r--r-- 2 root root 1024 may 21 18:55 folder
Script per calcolare le modalità di inode
#!/bin/bash
#### See https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout#Inode_Table
## Terminal measures:
x="$(( $(tput cols) / 2 ))" # Width of the terminal
y="$(( $(tput lines) / 2 ))" # Height of the terminal
## File descriptors:
declare -A types # Declare an associative array with file descriptors
types[f]='0x8000' # File
types[l]='0xA000' # Link
types[s]='0xC000' # Socket
types[d]='0x4000' # Directory
types[p]='0x1000' # Named pipe
types[b]='0x6000' # Block device
types[c]='0x2000' # Character device
## Permissions:
declare -A permission # Declare an associative array with permissions
permission[user_S]='0x800' # UID
permission[user_s]='0x840' # UID and user can execute
permission[user_r]='0x100' # User can read
permission[user_w]='0x80' # User can write
permission[user_x]='0x40' # User can execute
permission[group_S]='0x400' # GID
permission[group_s]='0x408' # GID and group can execute
permission[group_r]='0x20' # Group can read
permission[group_w]='0x10' # Group can write
permission[group_x]='0x8' # Group can execute
permission[other_T]='0x200' # Sticky bit
permission[other_t]='0x201' # Sticky bit and other can execute
permission[other_r]='0x4' # Other can read
permission[other_w]='0x2' # Other can write
permission[other_x]='0x1' # Other can execute
## Cleanup function:
function cleanup() {
tput cvvis # Make the cursor visible
tput rmcup # Restore saved terminal contents
stty sane # Fix problems caused by read -s
exit 0 # Exit gracefully
}
## Function to print at a specified position:
function pprint() {
tput cup $1 $2
printf "${@:3}"
}
## Function to clear the notification area:
function reset() {
pprint $((y+2)) $((x-40)) ' %.0s' {1..25} # Print 25 spaces
}
## Function to notify something to the user:
function notify() {
reset # Clear the notification area
pprint $((y+2)) $((x-40)) "$@" # Print the notification text
}
## If the terminal is smaller than 100x8, exit gracefully (self-explainatory):
if [ $x -lt 50 ] || [ $y -lt 5 ]; then
echo 'Error, I need a minimum of 100x10 lines to run'
exit 0
fi
## Initialize the terminal:
trap cleanup EXIT SIGHUP SIGINT SIGTERM # Call cleanup function after receiving ^C
stty -echo cbreak # Put terminal in silent mode
tput smcup # Save terminal contents
tput civis # Make the cursor inisible
## Draw the big box:
printf '\033[1;37m' # Color
pprint $((y-3)) $((x-48)) '\u2500%.0s' {1..97} # Upper line
pprint $((y+4)) $((x-48)) '\u2500%.0s' {1..97} # Lower line
for ((i=4;i>-4;i--)); do # Sides:
pprint $((y+i)) $((x-49)) '\u2502' # Left line
pprint $((y+i)) $((x+49)) '\u2502' # Right line
done # End sides
pprint $((y-3)) $((x-49)) '\u256D' # Upper-left corner
pprint $((y+4)) $((x-49)) '\u2570' # Lower-left corner
pprint $((y-3)) $((x+49)) '\u256E' # Upper-right corner
pprint $((y+4)) $((x+49)) '\u256F' # Lower-right corner
## Draw the small box:
printf '\033[1;35m' # Color
pprint $((y+1)) $((x-10)) '\u2501%.0s' {1..10} # Upper line
pprint $((y+3)) $((x-10)) '\u2501%.0s' {1..10} # Lower line
pprint $((y+2)) $((x-11)) '\u2503' # Left line
pprint $((y+2)) $((x+00)) '\u2503' # Right line
pprint $((y+1)) $((x-11)) '\u250F' # Upper-left corner
pprint $((y+3)) $((x-11)) '\u2517' # Lower-left corner
pprint $((y+1)) $((x+00)) '\u2513' # Upper-right corner
pprint $((y+3)) $((x+00)) '\u251B' # Lower-right corner
## Print type help:
pprint $((y-2)) $((x-44)) '\033[0;37mInode type: \033[1;37mf\033[0;37mile, \033[1;37md\033[0;37mirectory, \033[1;37ml\033[0;37mink, named \033[1;37mp\033[0;37mipe, \033[1;37ms\033[0;37mocket, \033[1;37mc\033[0;37mharacter device or \033[1;37mb\033[0;37mlock device.'
## Print permission help:
pprint $((y-1)) $((x-40)) '\033[0;36mPermission (\033[1;32mu\033[0;32mser\033[0;36m, \033[1;33mg\033[0;33mroup\033[0;36m or \033[1;31mo\033[0;31mther\033[0;36m): \033[1;36mr\033[0;36mead, \033[1;36mw\033[0;36mrite, e\033[1;36mx\033[0;36mecute, \033[1;36mhyphen\033[0;36m or \033[1;36mspace\033[0;36m to skip.'
pprint $((y+0)) $((x+8)) 's\033[1;36mt\033[0;36micky bit and executable, '
pprint $((y+1)) $((x+8)) 's\033[1;36mT\033[0;36micky bit not executable, '
pprint $((y+2)) $((x+8)) '\033[1;36ms\033[0;36metuid/setgid and executable, '
pprint $((y+3)) $((x+8)) '\033[1;36mS\033[0;36metuid/setgid not executable. '
## Endless loop:
while :; do
## Clear the input area:
pprint $((y+2)) $((x-10)) '% *s\n' 10 # Print 16 spaces
## Print mask in the input area:
printf '\033[1;37m' # Color for the type
pprint $((y+2)) $((x-10)) '\u2588' # Block for the type
printf '\033[1;36m' # Color for the permision
pprint $((y+2)) $((x- 9)) '\u2588%.0s' {1..9} # Blocks for the permission
## Loop through all variables to make a proper input:
for var in type {user,group,other}_{r,w,x}; do
## Assign colors and regex to fields:
case "$var" in
(type) color='\033[1;37m'; regex='^[fdlpscb]$' ;;
(other_x) regex='^[-xtT]$' ;;&
(user_x|group_x) regex='^[-xsS]$' ;;&
(user_[rw]|group_[rw]|other_[rw]) regex="^[-${var: -1}]$";;&
(user*) color='\033[1;32m' ;;
(group*) color='\033[1;33m' ;;
(other*) color='\033[1;31m' ;;
esac
## Change the pointer position:
pprint $((y+3)) $(((x-10)+pointer)) "${color}\u2501" # Print the pointer on its new position
if (( pointer > 0 )); then # If the pointer is not in the first position:
pprint $((y+3)) $(((x-10)+(pointer-1))) '\033[1;35m\u2501' # Clear the old pointer
fi
## Infinite loop until there is a valid input for the current character:
while :; do
printf "$color" # Set the character color
IFS= read -rn 1 $var # Read a character (even if it's a space)
declare $var="${!var// /-}" # Convert spaces to hyphens.
if [[ "$var" == "type" ]]; then # If the current variable is type:
declare $var="${!var//-/f}" # Convert "-" to "f"
fi
if [[ "${!var}" =~ $regex ]]; then # If there is a valid input:
reset # Clear error notification if any
break # Exit from this loop
else # Else:
notify "\033[1;31mWrong input!" # Print the error message
fi
done
## Print the entered value:
pprint $((y+2)) $(((x-10)+pointer)) "${!var}"
## Sum the current permission:
((mode+=permission[${var%_*}_${!var}]))
## Increment the pointer:
((pointer++))
done
## Post-read:
unset pointer # Reset the pointer
pprint $((y+3)) $((x-1)) "\033[1;35m\u2501" # Clear the pointer
read -n 1 # Wait for Return or another character
## Sum file descriptor type:
((mode+=${types[$type]}))
## Final commands:
mode=$(printf "%o" $mode) # Convert mode to octal (before this was decimal)
notify "\033[1;32mOctal mode:\033[1;34m $mode" # Print the octal mode
unset mode # Reset the mode
done
Visualizza lo script su GitHub
handicap
- La cartella non si apre. Non è possibile aprirlo a meno che non vengano inseriti i "dati della cartella non elaborati" che lo contenevano in origine.
Ulteriori letture
https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout#Inode_Table
Grazie a @tallus . Mi ha dato un grande suggerimento:
debugfs ha un comando edit_inode che consente di modificare direttamente un inode che consente di impostare il flag del file su una directory.