basic linux commands

Viewing, copying, moving and deleting files
ls        Display the contents of the current directory
ls -a     Display also hidden files and hidden directories
      
cp filename /path/dir_name         Copy filename into directory /path/dir_name
cp -r dir_name /path/dir_name2     Copy the entire dir_name into /path/dir_name2
cp filename1 filename2 /path/dir_name     Copy filename1 and filename2 into /path/dir_name
       
rm name        Remove a file or directory called name
rm -r name     Remove an entire directory as well as its included files and subdirectories
       
mv filename /path/dir_name     Move filename into /path/dir_name
mv filename1 filename2         Rename filename1 to filename2
       
cat filename     Display filenames contents
       
more filename     Display filename in pages. Use spacebar to view next page
       
head filename         Display filenames first 10 lines
head -15 filename     Display filenames first 15 lines
       
tail filename         Display filenames last 10 lines
tail -15 filename     Display filenames last 15 lines
       
pwd     Display current directory
       
cd /path/dir_name     Change to directory /path/dir_name
cd ..                 Go 1 directory up
       
mkdir dir_name     Create directory dir_name
rmdir dir_name     Delete directory dir_name

 
Finding files and text within files
updatedb            Update (create first time used) a database of all files under the root directory /
locate filename     Find file filename searching in the database
       
find / -name filename      Starting from the root directory search for the file called filename
find / -name *filename     Same as above but search for file containing the string filename
       
grep string /path/dir_name     Starting from /path/dir_name search for all files containing string
       
which application_name         Search $path for application app_name
whereis application_name       Search $path, man pages and source files for application_name

 
Archived files
Decompress
tar -xzf filename.tgz         Decompress tzg file
tar -xzf filename.tar.gz      Decompress tar.gz file
tar -xjf filename.tar.bz2     Decompress tar.bz2 file

Compress
tar -czf filename.tar /path/dir_name   Compress directory /path/dir_name to filename.tar
gzip -c filename > filename.gz         Compress /path/dir_name to filename.tar.gz
bzip2 -c filename > filename.bz2       Compress /path/dir_name to filename.tar.bz2

 
Using rpm files
rpm -ivh package.rpm             Install rpm called package.rpm
rpm -ivh --force package.rpm     Install rpm called package.rpm by force
rpm -Uvh package.rpm             Upgrade rpm called package.rpm
rpm -e package.rpm               Delete rpm called package.rpm
rpm -qpil package.rpm            List files in not-installed rpm called package.rpm
rpm -ql package.rpm              List files in installed rpm called package.rpm
rpm -q str                       List installed rpms containing the string str
rpm -qf /path/application_name     Display the rpm that contains application application_name

 
Starting and Stoping
startx              Start the X system
shutdown -h now     Shutdown the system now and do not reboot
halt                Same as above
shutdown -r now     Reboot
reboot              Same as above
shutdown -r +10     Reboot in 10 minutes

  
Mounting filesystems
mount -t vfat /dev/sd(a)(1) /mnt/c_drive     Mount the first partition 1 of the first hard disk drive a which is in fat32 vfat format under /mnt/c_drive directory
mount -t iso9660 /dev/cdrom /mnt/cdrom         Mount cdrom under /mnt/cdrom directory
umount /mnt/hda1     Unmout the above

 
User administration
users                Display users currently logged in
adduser username     Create a new user called username
passwd username      Define password for user called username
who                  List logged-in users
whoami               Display current user
finger username      Displays info about user username
su                   Log in as root from current login
su -                 Log in as root from current login and take root's path
exit                 Exit from console login (ie, logout).

 
Processes
command       Execute command in the foreground
command &     Execute command in the background
ctrl+z        Suspend a program
ctrl+c        Interrupt a program
ps            List all processes
kill -9 pid   Kill process with id pid
top           Monitor processes in real time

 
Networking
hostname         List the system's hostname
ifconfig         Set/Display network information
host ip          Resolves ip's hostname
ping ip/hostname     Check if ip/hostname is reachable
traceroute ip/hostname     Find network path to ip/hostname

  
System Information
uname -a              General system information
fdisk -l              List partition tables
cp filename /path/dir_name     Copy filename into directory /path/dir_name
df -T -h              List filesystem disk space usage
lspci                 List PCI devices
lsusb                 List USB devices
free -m               Display RAM+Swap usage

 
Program Compile
gcc -o output file.c         Compile a C program
./output                     Run a C program you have compiled
g++ -o output file.cpp       Compile a C++ program
./output                     Run a C++ program you have compiled
./configure && make && su -c 'make install'     Configure, compile and install a program with Makefile