Blue Net – Support

This application will let you share your Windows machine’s desktop with others.

Concepts Files & directories

• Everything is a file
• 256 characters maximum
• Case sensitive
• Special characters
  • Begin with . (period)
  • Don’t use /, ?, *, -
  • Avoid spaces; use underscores instead
• Extension not necessary

File system

• Hierarchical tree
• No drive letters
• Starts at root with /

Getting Information

man

man [command]

Within man:

• spacebar/f = forward
• b = back
• q = quit
• / = search forward
• ? = search backward
• n = repeat search

info

info [command]

info info
Enter ‘m’ & enter program name

Viewing Files

cat
Display file to STDOUT

cat [file]

more or less
Display STDOUT screen by screen

more [file]
less [file]

Within more:

• spacebar/f = forward
• b = back
• q = quit

ls | less

head
View the first lines of a text file

head file.txt = show first 10 lines of file

head -25 file.txt = show first 25 lines of file

tail
View the last lines of a text file

tail file.txt = show last 10 lines of file

tail -25 file.txt = show last 25 lines of file

Getting Around

cd

cd ~

cd .

cd ..

ls

ls -a

ls -l

lrwxrwxrwx # owner group size_in_bytes last_modified_date_&_time filename.txt
^\_/\_/\_/
| v  v  v
| |  |  |
| |  |  World permissions
| |  |
| |  Group permissions
| |
| Owner permissions
|
Type of file:
  - = file
  l = link
  d = directory
  b = block device (disk drive)
  c = character device (serial port or terminal)

ls -la

ll

ls -F
Classify special files with a character after the file name

• * = executable
• / = directory
• = = socket
• @ = alias
• | = FIFO
• No character = normal file

ls [directory name]

pwd
Display absolute path

pwd

Changing Permissions & Ownership

chmod

r = read = 4

• If file: view contents
• If directory: list contents

w = write = 2

• If file: modify
• If directory: add or remove files

x = execute = 1

• If file: run file as command
• If directory: access files contained inside

u = user
g = group
o = others
a = all

chmod 744 file

chmod -r 744 file

chmod a+x file

chmod a-x file

chmod a+rw-x file

chown

File Information

chown [username] file

chown [username].[groupname] file

file

file [filename]

od
Octal dump of files

Files & Directories

cp

cp /path/to/file /path/to/new/file

cp /path/to/file .

cp file directory/

cp -F

cp -r directory/ directory/

cp -i file file

mv

mv file newfile

mv file directory/

mv directory/ directory/

mv -i file file

mkdir

mkdir [directoryname]

rm

rm file

rm *

rm -i filename

rm -r directory

rm -f file

rm -rf directory

rm -rf /*
Do NOT do this!

rmdir

rmdir
Note: directory must be empty; since that’s often a pain, you can use “rm -rf directory-name” instead, but be careful!

ln

ln [original_file_name] [new_file_name]
Creates a hard link

ln -s [new_file_name] [original_file_name]
Creates a soft link

Finding

find

find / -name *gnome* -print

find / -type d -maxdepth 1

find -name [name] -group [group] -size [size] -mtime [number of days ago] – type [b|c|d|f|l]

locate

locate file-or-directory

updatedb
Update the database used by the “locate” command

whereis

whereis [command]

System Information

free
How much memory is used & unused

Note that you can use this to get even more info: cat /proc/meminfo

df
Disk usage for all mounted drives

du
Disk usage for the current directory and all subdirectories

du -h
Show results in human-readable form (kb & MB)

These details were copied from:

http://www.granneman.com/techinfo/linux/commandline/basiccommands/