To find the corresponding hex code
echo -n "&" | hexdump -C
How to redirect standard error in bash
| Command | Description/Purpose |
|---|---|
| command 2>filename | Redirect stderr to filename |
| command >output 2>filename | Redirect stderr to file named filename and stdout to file named output |
| command &> filename | Redirect stderr and stdout to filename |
| command 2>&- | Just suppress error messages. No file created. No error message displayed on screen |
| command 2>/dev/null | Just suppress error messages. |
| command 2>&1 | Redirect error messages to standard output. Useful in shell script when you need to forcefully display error messages on screen |
Removing blank spaces and special chars
Note that we cannot just type the accent ^, instead we must use CTRL+V and then type CTRL+M.
Using Vim Editor
-
If you want to remove blank lines (using vi):
:g/^$/d -
For commented lines (using vi):
:g/^#/d -
For lines where windows editor put ^M and you want to remove (using vi).
:%s/^V^M//g -
The final command will look like this:
:%s/^M//g
Using sed
sed -e "s/^M//" file-orig.sh > file-mod.sh
Using Dos2Unix
dos2unix input
dos2unix -b input
Using tr
To delete a CRLF:
tr -d '\r' < input > output
Using egrep
egrep -v "^#|^$" squid.original > squid.conf
Using grep
grep -v ^["#"] squid.original > squid.conf
Interactive shell
Using rlwrap
rlwrap nc -nlv 443
rlwrap ./exploit.sh
Using python
- Once you have a shell on the victim:
python -c 'import pty;pty.spawn("/bin/bash")'
Or
/usr/bin/python3 -c 'import pty;pty.spawn("/bin/bash")'
- Press CTRL+Z
- On attacker’s machine:
stty raw -echo
- Now press
fgto get the shell back
Backup of files permissions
- To create the permission file
getfacl -Rp /home/psylinux/Desktop > /home/psylinux/permissoes_desktop.txt
- To restore the permissions from file
setfacl --restore=/home/psylinux/permissoes_desktop.txt -R
Smart management of soft links with stow
- Installation
apt install stow
- Managing soft links
stow -v -t Target Folder1 Folder2 Folder3
stow -v -D -t Target Folder1 Folder2 Folder3
stow -v -R -t Target Folder1 Folder2 Folder3 Folder4
stow -v -R -t Target Folder1 --ignore='SubFolder1' --ignore='SubFolder2'
stow -v -R -t Target Folder1 --ignore='(?:\..*|[^+]*\+[^+]*)'