Linux common basic Commands (CAT)

Cat command

Action: Connect multiple files and print to the screen output, or redirect to another file, or to view a single file, or multiple files.

Format:

Cat [option] [file]

1, the simplest use, directly with the file name, view the contents of the file

[Email protected]:~/linux/catls[email protected]:~/linux/catecho ' hello,my name is Ghostwu . ' > test.txt[email protected]:~/linux/catcat  test.txt hello,my name is GHOSTWU, how is it? [email protected]:~/linux/Cat

2, you can also use the following methods to write to the file or append content

[Email protected]:~/linux/catlstest.txt[email protected]:~/linux/catCat >> test.txt << EOF> This is what I added > This is the third line of content > eof[email protected]: ~/linux/catcat  test.txt hello,my name is Ghostwu. This is what I added. This is the third line of content.

Both 3,-n and-B are numbered, and-B does not number blank lines

[Email protected]:~/linux/Cat$Cattest.txt hello,my name is GHOSTWU?This is what I added. This is the third line of content [email protected]:~/linux/Cat$Cat>> Test.txt <<EOF> > >Two blank lines are added to the above>Eof[email protected]:~/linux/Cat$Cattest.txt hello,my name is GHOSTWU?This is what I added. This is the third line with two blank lines added [email protected]:~/linux/Cat$Cat-N test.txt1Hello,my name is GHOSTWU.2This is what I added.3This is the third line of content4         5         6There are two blank lines added [email protected]:~/linux/Cat$Cat-b test.txt1Hello,my name is GHOSTWU.2This is what I added.3This is the third line of content4There are two blank lines added [email protected]:~/linux/Cat$

4,-E Displays the dollar sign at the end of each line

[Email protected]:~/linux/catcat -E test.txt hello,my name is GHOSTWU. $ This is what I added $ this is the third line of content $$$ added two blank lines above

5,-s: Put more than two consecutive empty lines into a

[Email protected]:~/linux/Cat$Cat-N test.txt1Hello,my name is GHOSTWU.2This is what I added.3This is the third line of content4         5         6         7         8Two blank lines are added to the above9        Tena blank line is added to the above [email protected]:~/linux/Cat$Cat-NS Test.txt1Hello,my name is GHOSTWU.2This is what I added.3This is the third line of content4         5Two blank lines are added to the above6         7A blank line is added to the above

6. Delete file contents using/dev/null

[Email protected]:~/linux/catcat  test.txt hello,my name is GHOSTWU. This is what I added. This is the third line with two blank lines added to the line [email protected]:~/linux/catcat /dev/null > test.txt[email protected]:~/linux/catCat

7, using redirection to write content

[Email protected]:~/linux/cat cat test.txt [email protected]:~/linux/catCat > test.txtthis is GHOSTWU what is you[email protected]:~/linux/catcat  test.txt This is ghostwuhow is

Content input completed, with Ctrl+d or CTRL + C interrupt input

8, display multiple file contents

[Email protected]:~/linux/catcat > abc.txtthis is abc.txt[email protected]:~/linux/ Cat Cat Test.txt abc.txt This is ghostwuhow be Youthis is Abc.txt

Linux common basic Commands (CAT)