#basic linux

Basic File Navigation: df command in Linux provides disk space usage information of your file systems.$ df –h (in human readable format) [oracle@db-uat trace]$ df -hFilesystem Size Used Avail Use% Mounted ondevtmpfs 16G 0 16G 0% /devtmpfs 16G 12K 16G 1% /dev/shmtmpfs 16G 258M 16G 2% /runtmpfs 16G 0 16G 0% /sys/fs/cgroup/dev/mapper/OSVG-rootlv 10G 253M 9.8G 3% //dev/mapper/OSVG-usrlv 30G 5.4G…

cat  {any file name}               –         This is a way to list the contents of  files  to the screen.

cd   {any directorys}              –        Change directory

cd ..                                           –        Move to the parent directory of the current directory.

cd ~                                          –          Move to the user’s home directory which is “/home/username”.

cp                                             –          Copy files

cp  (sr.file) (des.file)            –         Copy the files “sr.file” to the file “des.file” in the current working directory.

cp -i (sr.file) (des.file)        –      With the “-i” option, if the file “des.file” exists, you will be prompted before overwrite

cp -i /data/sr.file                 –         Copy the file “/data/sr.file” to the current working directory and name it “sr.file”.

cp -dpr (srcdir) (destdir)    –         Copy all files from the directory “srcdir” to the directory “destdir” preserving links.

dd                                            –          Disk duplicate.copy a file convert and formitting according to oprands.

df                                            –            Show the amount of disk space used on each mounted filesystem.

ln                                            –            (hard link)   Creates a symbolic link to a file.

ln -s                                        –            (soft link) test symlink Creates a hard link to a file

locate                                     –             A fast database driven file locator.

slocate -u                              –      command builds the database. This command must be used before searching for files.

locate whereis                      –            Lists all files whose names contain the string “whereis”.

logout                                    –            Logs the current user off the system.

ls                                             –            List files in the current working directory and only show the file name.

ls -al                                       –             List all files in the current working directory in long listing format showing .

ls -al |more                          –              If the directory listing is longer than a page, it will be listed one page at a time.

mv                                         –              Move or rename files

mv -i (srcfile) (destfile)     –              Move the file from “srcfile” to “destfile”.

pwd                                       –               Show the name of the current working directory

more /etc/profile               –               Lists the contents of the “/etc/profile” file to the screen one page at a time.

shutdown                            –               Shuts the system down.

shutdown -h                       –               now Shuts the system down to halt immediately.

shutdown -r                        –                now Shuts the system down immediately and the system reboots.

whereis                               –                 Show where the binary, source and manual page files are for a command

whereis  ls                          –                 Locates binaries and manual pages for the ls command.

init 0                                   –                 shutdown computer

ifup (eth0,eth1,etc)          –                 activating internet connection

if config                              –                  show the configuration of linux system