Shell-array usage

From: http://www.jb51.net/article/34323.htm

Note: The subscript of the array in Shell starts from 0 by default.

1. Place the string in an array to obtain its length.

Copy the Code as follows:
#! /Bin/bash
STR = "a B -- n d"
Array = ($ Str)
Length =$ {# array [@]}
Echo $ Length

For (I = 0; I <$ length; I ++ ))
Do
Echo $ {array [$ I]}
Done

 

Execution result:
[Oracle @ 99bill-as9 array] $ sh length. Sh
4
A

-- N
D

2) print the string:

Copy the Code as follows:
#! /Bin/bash
STR = "a B C"
For I in $ Str
Do
Echo $ I
Done
Or:
#! /Bin/bash
STR = "a B C"
Array = ($ Str)
For (I = 0; I <$ {# array [@]}; I ++ ))
Do
Echo $ {array [$ I]}
Done

Execution result:
A

C

2. When a string is separated by other characters

Copy the Code as follows:
#! /Bin/bash

Str2 = "A # B # C"
A = ($ (echo $ str2 | tr '# ''' | tr-S ''))
Length =$ {# A [@]}

For (I = 0; I <$ length; I ++ ))
Do
Echo $ {A [$ I]}
Done
# Echo $ {A [2]}

 

Execution result:
A

C

3. Other operations on Arrays

Copy the Code as follows:
#! /Bin/bash
STR = "a B -- N dd"
Array = ($ Str)
Length =$ {# array [@]}

# Ouput The first array element outputs the first element of the array.
Echo $ Array

# Use subscript way access array access to array elements using the following method
Echo $ {array [1]}

# Output the array to output this array
Echo $ {array [@]}

# Output in the array subscript for 3 the length of the element output the length of the element marked as 3 in the array
Echo $ {# array [3]}

# Output in the array subscript 1 to 3 element: Elements marked as 1 to 3 in the output Array
Echo $ {array [@]: 1: 3}

# Output in the array subscript greater than 2 elements output the element whose subscript is greater than 2
Echo $ {array [@]: 2}

# Output in the array subscript less than 2 elements output the element whose subscript is less than 2 in the array
Echo $ {array [@]: 2}

Execution result:
A

A B -- N dd
2
B -- N dd
-- N dd
A B

4. Access a string through traversal (separated by spaces by default. When strings are separated by other separators, refer to 2)

Copy the Code as follows:
#! /Bin/bash
STR = "A -- M"
For I in $ Str
Do
Echo $ I
Done

Execution result:
A
-- M

5. How to use echo to output a string STR = "-n". Because-N is a parameter of ECHO, the General echo "$ Str" method cannot be output.

The solution can be:

Copy the Code as follows:
Echo x $ STR | SED's/^ x //'
Echo-ne "$ STR \ n"
Echo-e "$ STR \ n \ c"
Printf "% s \ n" $ STR (this can also be done)

Detailed source reference: http://www.jb51.net/article/34323.htm