"Self-learning Linux" Linux file System Management (III)

Cat: Connect and display
-N: Numbering all lines of the output
-e: Show $ at end of each line

Split screen display: more, less

Head: View top n rows, n defaults to 10
-N

Tail: To view the following n rows, n defaults to 10
-N

Cut
-D: Specifies the field delimiter, which is the default space
-F: Specify the fields to display

Sort: Text sort
-N: Numeric sorting
-R: Descending
-T: Field delimiter
-K: Which field is sorted by keyword
-U: The same row is only displayed once after sorting
-F: Ignore character capitalization when sorting

Uniq
-C: Shows the number of rows in a file that repeats
-D: Show only duplicate rows

WC (Word count): text statistics
-L: Count rows
-W: Count words
-C: Statistics of bytes
-L: Prints the longest line length

Character Processing commands:
TR: converting or deleting characters
[TR AB-AB]
-D: Delete all characters that appear in the character set

Command history:
History: Viewing command Histories
-C: Empty command history
-D OFFSET [n]: Delete command at specified position
-W: Save the Command history to the history file

Environment variables:
Path: Command Search Path
[Echo $PATH]

Histsize: Command history buffer size
[Echo $HISTSIZE]

The use of command history tips:
!n: Executes the nth command in the command history
!-n: Executes the last nth command in the command history
!: Executes the previous command
!string: The most recent command in the command history that starts with a specified string
!$: Reference the last parameter of the previous command
Shortcut key: esc+. or ALT +.

Command aliases:
Alias cmdalias= ' COMMAND [option] [argument] '

Ualias cmdalias: Canceling command aliases

Command substitution: $ (command), anti-quote: ' command '

Quotes supported by bash:
": Command substitution
"": weak reference, can implement variable substitution
': Strong reference, do not complete variable substitution

File name wildcard, globbing
*: Any character of any length
?: any single character
[]: matches any single character within the specified range
[Abc],[a-m],[a-za-z],[0-9a-za-z]
[: Space:]: white space character
[:p UNCT:]: Punctuation characters
[: Low:]: Small Letter
[: Upper:]: Uppercase
[: Alpha:]: Uppercase and lowercase letters
[:d igit:]: Number
[: Alnum:]: Numbers and size letters
[^]: matches any single character outside the specified range
For example [[: Alpha:]]*[[:space:]]*[^[:alpha:]]

This article is from the "Maskpaperman" blog, make sure to keep this source http://mrros.blog.51cto.com/9403540/1851976

"Self-learning Linux" Linux file System Management (III)