Unix commands in Mac OS X

Reference: http://www.renfei.org/blog/mac-os-x-terminal-101.html

One command line includes 4 Parts:command Name, Options, Arguments, Extras.

Man <command-name> : Give The Manual of this command.

Absolute and relative paths

/ : Root Directory

 .. : Parent directory.

Directory Operations

pwd : Print working directory, which'll show the absolute path of current folder.

ls : List directory contents. Ls–la:list all contents including hidden contents.

CD : Change directory.

mkdir : Make directories.

rmdir: Remove directories.

mvdir: Move or rename a directory.

Handling special characters (space, bracket, quotation mark,!, $, &, *,;, \, ...)

\ : Use back slash before the character. CD punlic/drop\ box/(= CD "Public/drop box").

File operations

cp : Copy files.

mv : Move files.

rm : Remove Files

VI: or VIM:A Programmers text editor

Nano: Nano ' s another editor, an enhanced free Pico clone.

cat : Concatenate and print files. It reads files sequentially, writing them to the standard output.

Cat File1:will Print the contents of file1 to the standard output.

Cat file1 file2 > File3:will sequentially print the cntents of File1 and File2 to the file3.

Cat File1–file2–file3:???

od: Octal, Decimal, hex, ASCII dump

Less:

which: Locate a program file in the user ' s path.

Find : Find. -name "*.C"-print

file: Determine file type.

Head: Display first lines of a file. head-10 filename.

　　tail: Display The last part of a file.

cut: Cut out selected portions of each lie of a flie.

colrm: Remove columns from a file. COLRM 8 filename

diff: Compare files on line.

sort: Sort lines of text file.

uniq: report or filter out repeated lines in a file.

Comm: Select or Regject lines common to the files.

WC: Word, line, character, and byte count.

NL: line numbering filter. NL file1 > File2

Process actions

　　PS : Process status PS u

　　kill : Terminate or signal a process. Kill-9 30142

The kill utility sends a signal to the processes specified by the PID operand (s).

Only the super-user could send signals to other user ' s processes.

Some of the more commonly used signals:

1 HUP (Hang Up)

2 INT (interrupt)

3 QUIT

6 ABRT (Abort)

9 KILL (non-catchable, non-ignorable Kill)

ALRM (Alarm)

term (software termination signal)

Time Operation:

　　Date: Display or set date and time.

　　cal: Display a calendar and the date of Easter Cal 4 2015.

Time: Time command Execution (totoal time elapsed.)

System Management

W: Display who was logged in and what they was doing.

　　who:

WhoAmI:

su : Substitute user identify.

Sudo : Substitute user do, or super user does. It allows a permitted user to execute a command as the Superuser or another user.

Unix commands in Mac OS X