Linux Getting Started common commands (3)

One. Use of common wildcard characters

* represents 0 or any number of characters

？ Represents 0 or a character

~ Represents the current user home directory

~username represents user home directory

. Represents the current directory

.. Represents the previous level of the directory

[0-9] matches any number between 0-9

[ABC] matches any one of the characters in the list

[^ABC] matches any character other than the one in the list

[:d Igit:] matches any one of the 0-9 characters

[: Lower:] Any lowercase letter

[: Upper:] Any uppercase letter

[: Alpha:] any case letter

[: Alnum:] arbitrary letters and numbers

[: Space:] Space

[:p UNCT:] Punctuation

Exercises:

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3

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4

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5

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/85/2F/wKiom1ecRxCh4HlmAAAC3TRM5cM908.png "style=" float: none; "title=" 6.png "alt=" Wkiom1ecrxch4hlmaaac3trm5cm908.png "/>

6

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1

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2

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Two. CP command use detailed

CP-A archives can be used to back up the equivalent of-DR--preserve=all

cp-d Copy only linked file properties, not copy source files

Cp-f when the destination file exists but cannot be started, delete the rebuild

Cp-i Interactive operation

Cp-l Creating a hard link

Cp-s Creating a soft link

Cp-p equivalent to--preserve=ownership,mode,timestamps

1. When the source file is a file

(1) When the target does not exist, create a new destination file and copy the source file contents to the destination file

650) this.width=650; "src=" Http://s5.51cto.com/wyfs02/M01/85/3B/wKioL1edpxeg_WvrAAAOJioaNZM284.png "title=" 1.png " alt= "Wkiol1edpxeg_wvraaaojioanzm284.png"/>

(2) When the target exists and is a file, overwrite the original file content, the original file part of the property is unchanged

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/85/3B/wKioL1edp93hEfMRAAAMchPK824429.png "title=" 2.png " alt= "Wkiol1edp93hefmraaamchpk824429.png"/>

(3) When the target exists and is a directory, create a new file with the same name as the source file in the directory

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2. When the source file is multiple files

(1) The target file does not exist, error

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(2) target exists, but file, error

650) this.width=650; "src=" Http://s5.51cto.com/wyfs02/M00/85/3B/wKiom1edqrCzOjPlAAAFZSJuHSo385.png "title=" 5.png " alt= "Wkiom1edqrczojplaaafzsjuhso385.png"/>

(3) The target exists and is a directory, create a new file with the same name as the source file under the target directory, and copy the source file

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/85/3B/wKiom1edquXgDJQgAAAIUWKKGo4779.png "title=" 6.png " alt= "Wkiom1edquxgdjqgaaaiuwkkgo4779.png"/>

3. When the source file is a directory

(1) When the target file does not exist, create a new directory and copy the files under the directory to the target directory.

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(2) When the target file exists but is a file, the error

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(3) When the target file exists and is a directory, copy the files from the source directory to the target directory

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Answer 1.

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2.

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Three. Relative path description

Relative path refers to relative to working directory or to a directory

(1) View/etc/redhat-release, discover that it is a connection file, and that the source file is not the same size as the connection file

650) this.width=650; "src=" Http://s5.51cto.com/wyfs02/M00/85/32/wKiom1ecaL_A6YjDAAALdsqnLzY720.png "title=" Found two files of different sizes "alt=" Wkiom1ecal_a6yjdaaaldsqnlzy720.png "/>

(2) Copy/etc/redhat-release to/testdir

650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M00/85/32/wKioL1eca8aTsWeTAAAJZOxJnqY773.png "title=" 1.png " alt= "Wkiol1eca8atswetaaajzoxjnqy773.png"/>

found that the redhat-release size under/testdir is equal to/etc/centos-release

(3) Copy the/etc/redhat-release connection file to the/testdir

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found that the amber icon has been flashing, indicating that the source file could not be found, but the/testdir/redhat-release size and/etc/redhat-release are equal, at this time the system thinks centos-release is relative to/testdir/ Redhat-release is located in/testdir, but/testdir under no

(4) You can make a mistake by creating a new/testdir/centos-release under/testdir.

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Summary: In general, or absolute path, not prone to error

This article is from the "Hello" blog, so be sure to keep this source http://tianzhi.blog.51cto.com/11880607/1832397

Linux Getting Started common commands (3)