mkdir – make directories
mkdir [OPTION] DIRECTORY
Create the DIRECTORY(ies), if they do not already exist.
Mandatory arguments to long options are mandatory for short options too.
-m, mode=MODE set permission mode (as in chmod), not rwxrwxrwx – umask
-p, parents no error if existing, make parent directories as needed
-v, verbose print a message for each created directory
-help display this help and exit
-version output version information and exit
cd – change directories
Use cd to change directories. Type cd followed by the name of a directory to access that directory.Keep in mind that you are always in a directory and can navigate to directories hierarchically above or below.
mv- change the name of a directory
Type mv followed by the current name of a directory and the new name of the directory.
Ex: mv testdir newnamedir
pwd – print working directory
will show you the full path to the directory you are currently in. This is very handy to use, especially when performing some of the other commands on this page
rmdir – Remove an existing directory
Removes directories and files within the directories recursively.
chown – change file owner and group
chown [OPTION] OWNER[:[GROUP]] FILE
chown [OPTION] :GROUP FILE
chown [OPTION] –reference=RFILE FILE
Change the owner and/or group of each FILE to OWNER and/or GROUP. With –reference, change the owner and group of each FILE to those of RFILE.
-c, changes like verbose but report only when a change is made
-dereference affect the referent of each symbolic link, rather than the symbolic link itself
-h, no-dereference affect each symbolic link instead of any referenced file (useful only on systems that can change the ownership of a symlink)
change the owner and/or group of each file only if its current owner and/or group match those specified here. Either may be omitted, in which case a match is not required for the omitted attribute.
-no-preserve-root do not treat `/’ specially (the default)
-preserve-root fail to operate recursively on `/’
-f, -silent, -quiet suppress most error messages
-reference=RFILE use RFILE’s owner and group rather than the specifying OWNER:GROUP values
-R, -recursive operate on files and directories recursively
-v, -verbose output a diagnostic for every file processed
The following options modify how a hierarchy is traversed when the -R option is also specified. If more than one is specified, only the final one takes effect.
-H if a command line argument is a symbolic link to a directory, traverse it
-L traverse every symbolic link to a directory encountered
-P do not traverse any symbolic links (default)
chmod – change file access permissions
chmod [-r] permissions filenames
r Change the permission on files that are in the subdirectories of the directory that you are currently in. permission Specifies the rights that are being granted. Below is the different rights that you can grant in an alpha numeric format.filenames File or directory that you are associating the rights with Permissions
u – User who owns the file.
g – Group that owns the file.
o – Other.
a – All.
r – Read the file.
w – Write or edit the file.
x – Execute or run the file as a program.
CHMOD can also to attributed by using Numeric Permissions:
400 read by owner
040 read by group
004 read by anybody (other)
200 write by owner
020 write by group
002 write by anybody
100 execute by owner
010 execute by group
001 execute by anybody
ls – Short listing of directory contents
-a list hidden files
-d list the name of the current directory
-F show directories with a trailing ‘/’
executable files with a trailing ‘*’
-g show group ownership of file in long listing
-i print the inode number of each file
-l long listing giving details about files and directories
-R list all subdirectories encountered
-t sort by time modified instead of name
cp – Copy files
cp myfile yourfile
Copy the files “myfile” to the file “yourfile” in the current working directory. This command will create the file “yourfile” if it doesn’t exist. It will normally overwrite it without warning if it exists.
cp -i myfile yourfile
With the “-i” option, if the file “yourfile” exists, you will be prompted before it is overwritten.
cp -i /data/myfile
Copy the file “/data/myfile” to the current working directory and name it “myfile”. Prompt before overwriting the file.
cp -dpr srcdir destdir
Copy all files from the directory “srcdir” to the directory “destdir” preserving links (-poption), file attributes (-p option), and copy recursively (-r option). With these options, a directory and all it contents can be copied to another dir
ln – Creates a symbolic link to a file.
ln -s test symlink
Creates a symbolic link named symlink that points to the file test Typing “ls -i test symlink” will show the two files are different with different inodes. Typing “ls -l test symlink” will show that symlink points to the file test.
locate – A fast database driven file locator.
This command builds the slocate database. It will take several minutes to complete this command.This command must be used before searching for files, however cron runs this command periodically on most systems.locate whereis Lists all files whose names contain the string “whereis”. directory.
more – Allows file contents or piped output to be sent to the screen one page at a time
less – Opposite of the more command
cat – Sends file contents to standard output. This is a way to list the contents of short files to the screen. It works well with piping.
cat files – Prints the contents of the specified files.
whereis – Report all known instances of a command
wc – Print byte, word, and line counts
bg jobs Places the current job (or, by using the alternative form, the specified jobs) in the background, suspending its execution so that a new userprompt appears immediately. Use the jobs command to discover the identities of background jobs.
cal month year – Prints a calendar for the specified month of the specified year.
clear – Clears the terminal screen.
cmp file1 file2 – Compares two files, reporting all discrepancies. Similar to the diff command, though the output format differs.
diff file1 file2 – Compares two files, reporting all discrepancies. Similar to the cmp command, though the output format differs.
dmesg – Prints the messages resulting from the most recent system boot.
fg jobs – Brings the current job (or the specified jobs) to the foreground.
file files – Determines and prints a description of the type of each specified file.
find path -name pattern -print
Searches the specified path for files with names matching the specified pattern (usually enclosed in single quotes) and prints their names. The findcommand has many other arguments and functions; see the online documentation.
finger users – Prints descriptions of the specified users.
free – Displays the amount of used and free system memory.
Opens an FTP connection to the specified host, allowing files to be transferred. The FTP program provides subcommands for accomplishing file transfers; see the online documentation.
head files – Prints the first several lines of each specified file.
ispell files – Checks the spelling of the contents of the specified files.
kill – signal process_ids
Kills the specified processes, sends the specified processes the specified signal (given as a number or name), or prints a list of available signals.
killall – signal program
Kills all processes that are instances of the specified program or sends the specified signal to all processes that are instances of the specified program.
mail – Launches a simple mail client that permits sending and receiving email messages.
man section title – Prints the specified man page.
ping host – Sends an echo request via TCP/IP to the specified host. A response confirms that the host is operational.
reboot – Reboots the system (requires root privileges).
shutdown -r minutes
Shuts down the system after the specified number of minutes elapses (requires root privileges). The -r option causes the system to be rebooted once it has shut down.
sleep time – Causes the command interpreter to pause for the specified number of seconds.
sort files – Sorts the specified files. The command has many useful arguments; see the online documentation.
split file – Splits a file into several smaller files. The command has many arguments; see the online documentation
sync – Completes all pending input/output operations (requires root privileges).
telnet host – Opens a login session on the specified host.
top – Prints a display of system processes that’s continually updated until the user presses the q key.
traceroute host – Uses echo requests to determine and print a network path to the host.
uptime – Prints the system uptime.
w – Prints the current system users.
wall – Prints a message to each user except those who’ve disabled message reception. Type Ctrl-D to end the message.
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|
|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|
|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 -hiv package.rpm||Install rpm called package.rpm|
|rpm -hiv –force package.rpm||Install rpm called package.rpm by force|
|rpm -hUv 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|
|Same as above|
|shutdown -r now||Reboot|
|reboot||Same as above|
|shutdown -r +10||Reboot in 10 minutes|
|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 dormat under /mnt/c_drive directory|
|mount -t iso9660 /dev/cdrom /mnt/cdrom||Mount cdrom under /mnt/cdrom directory|
|umount /mnt/hda1||Unmout the above|
|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).|
|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|
|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|
|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|
|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|
Thảo luận bài viết tại forum : http://forum.gocit.vn/threads/basic-linux-commands.486/