1 User commands
2 Programming interfaces for kernel system calls
3 Programming interfaces to the C library
4 Special files such as device nodes and drivers
5 File formats
6 Games and amusements
7 Misc
8 Sysadmin commands
apropos - search the list of man pages for possible matches based on a search term.
apropos crack
cracklib-check (8) - Check passwords using libcrack2
cracklib-format (8) - cracklib dictionary utilities
cracklib-packer (8) - cracklib dictionary utilities
cracklib-unpacker (8) - cracklib dictionary utilities
create-cracklib-dict (8) - Check passwords using libcrack2
fcrackzip (1) - a Free/Fast Zip Password Cracker
fcrackzipinfo (1) - display zip information
update-cracklib (8) - Regenerate cracklib dictionary
whatis (1) - display one-line manual page descriptions
info (1) - read Info documents
zless (1) - file perusal filter for crt viewing of compressed text
read .gzip
echo Front-{A,B,C}-Back
Front-A-Back Front-B-Back Front-C-Back
echo Num_{1..10}
Num_1 Num_2 Num_3 Num_4 Num_5 Num_6 Num_7 Num_8 Num_9 Num_10
echo {Z..A}
Z Y X W V U T S R Q P O N M L K J I H G F E D C B A
echo {Z,A{1..5},b{1..3}}
Z A1 A2 A3 A4 A5 b1 b2 b3
ctrl+a move cursor to the beginning of the line.
ctrl+e move cursor to the end of the line.
ctrl+f move cursor forward one char.
ctrl+b move cursor backward one char.
alt+f move cursor forward one word.
alb+b move cursor backward one word.
ctrl+l clear.
ctrl+d delete the char.
ctrl+t transpose the current char with the preceding.
alt+t transpose the word with the preceding.
alt+l convert the chars from the cursor to the end to lowercase.
alt+u convert the chars from the cursor to the end to uppercase.
ctrl+k kill text from cursor to end of the line.
ctrl+u kill text from cursor to beginning of the line.
alt+d kill text from cursor to end of the word.
alt+bksp kill text from cursor to beginning of the word.
ctrl+y yank text from kill-ring and insert it at the cursor location.
$ variables
~ users
commands
!n expands the n° line of the history
!str repeat last list item starting with string
!?str repeat last list item containing string
ctrl+r search backwards in the history
ctrl-j copies the text result of search
-rw-rw-r-- 1 andrea andrea 1 mag 12 15:30 foo.txt
first char file type
chars 1-10 file mode
owner permission
group permission
world permission
The file type can be:
- regular file
d directory
l symbolic link
c character special file
b block special file
-rwx------ regular file readable, writable and executable only by the file owner.
-rw------- regular file readable and writable only by the file owner.
-rw-r--r-- regual file readable and writable by the owner. Members of file's owner group can read, world can read.
lrwxrwxrwx symbolic link with dummy permissions.
drwxrwx--- directory, owner and members of the same group may enter the dir and create, rename and remove files within it.
drwxr-x--- directory, owner may enter the directory and create, rename and delete files. Members of the same group may enter but cannot create, delete, or rename files.
Changes the mode (permission) of a file or directory with either octal number representation and symbolic representation.
Octal representation
0 000 ---
1 001 --x
2 010 -w-
3 011 -wx
4 100 r--
5 101 r-x
6 110 rw-
7 111 rwx
examples
chmod 777 foo.txt --> -rwxrwxrwx 1 andrea andrea 1 mag 12 15:30 foo.txt
chmod 600 foo.txt --> -rw------- 1 andrea andrea 1 mag 12 15:30 foo.txt
chmod 640 foo.txt --> -rw-r----- 1 andrea andrea 1 mag 12 15:30 foo.txt
chmod 711 fox.txt --> -rwx--x--x 1 andrea andrea 1 mag 12 15:30 foo.txt
Symbolic representation:
- whom the change will affect: u,g,o,a (user,group owner, others, all)
- which operation will be performed: +-= (add,remove,apply and remove others)
- which permission will be set: rwx
examples:
chmod a=rwx foo.txt --> -rwxrwxrwx 1 andrea andrea 1 mag 12 15:30 foo.txt
chmod a-rwx,u=rw foo.txt --> -rw------- 1 andrea andrea 1 mag 12 15:30 foo.txt
Sets the file mode creation mask to mask & 0777 (uses only the permission bits). It uses octal notation to express a mask of bits to be removed from a file's mode attributes.
example:
umask 0002 --> -rw-rw-r-- 1 andrea andrea 0 mag 12 17:26 foo.txt
umask 0000 --> -rw-rw-rw- 1 andrea andrea 0 mag 12 17:26 foo.txt (default)
Using chmod is possible to set uid and gid to root.
chmod u+s foo.txt --> -rwsrw-rw- 1 andrea andrea 0 mag 12 17:30 foo.txt
chmod g+d dir/