The cat of the Linux Common Operation command

Cat: Display text file

You can use the Cat command to display the contents of a text file, or you can append the contents of several files to another file. If no file is specified, or if the file is "-", it is read from the standard input.

Command syntax:

Cat [Options] [file]

Options:

-N: Numbering all lines of the output

-B: Number of non-null output lines

-S: Displays a blank line in a row when a row is encountered

-e: Show $ at end of each line

Example:

1. Displays the contents of the/etc/inittab  file [[email protected] ~]# cat /etc/inittab # inittab  is only used by upstart for the default runlevel.## adding  other configuration here will have no effect on your system.##  System initialization is started by /etc/init/rcS.conf## Individual  Runlevels are started by /etc/init/rc.conf## ctrl-alt-delete is handled  by /etc/init/control-alt-delete.conf## terminal gettys are handled by  /etc/init/tty.conf and /etc/init/serial.conf,# with configuration in /etc/ sysconfig/init.## for information on how to write upstart event  Handlers, or how# upstart works, see init (5),  init (8), and  Initctl (8). ## default runlevel. the runlevels used are:#   0 - halt  (Do NOT  set initdefault to this) #   1 - single user mode#    2 - Multiuser, without NFS  (the same as 3, if  you do not have networking) #   3 - full multiuser  mode#   4 - unused#   5 - x11#   6  - reboot  (do not set initdefault to this) # id:3:initdefault:

3. Enter the contents of the file test1 with the line number into the test2 file [[email protected] data]# cat-n test1>>test2[[email protected] data]# cat Test2 1 SFSG 2 Faqeg 3 AGSG

5. Create a file Test1 file using the cat command [[email protected] data]# cat >test1<<eof #开头和结尾的EOF可用任意字符替换, used eofsfsgfaqegagsgeof[[ Email protected] data]# cat test1 #查看tes1中的文件内容sfsgfaqegagsg

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The cat of the Linux Common Operation command