Go The usage of read in the shell is detailed

The usage of read in the shell is detailed

Original: http://blog.csdn.net/jerry_1126/article/details/77406500

The common usage of read is as follows:

Read-[pstnd] var1 var2 ...

-P Prompt Statement
-N Character Count
-S shielded Echo
-T wait time
-D Input Demarcation

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2. Read # reads a line from standard input and assigns a value to a specific variable reply
4. [Email protected]~# Read
6. hello,world!
8. [Email protected]~# Echo $REPLY
10. hello,world!
14. Read name # reads input from standard input and assigns a value to the variable name
16. [Email protected]~# Read name
18. Jerry
20. [Email protected]~# Echo $name
22. Jerry
26. Read Var1 var2 # The first variable is placed in Var1, and the second variable is placed in the VAR2
28. [Email protected]~# read FirstName LastName
30. Jerry Gao
32. [Email protected]~# echo "FirstName: $firstname LastName: $lastname"
34. Firstname:jerry Lastname:gao
38. ). Read-p "Text" # print hint ' text ', wait for input, and store input in reply
40. [Email protected]~# read-p ' please Enter your name:--> '
42. Please Enter your Name:-->jerry
44. [Email protected]~# Echo $REPLY
46. Jerry
50. Read-p "text" var # print hint ' text ', wait for input, and store input in Var
52. [Email protected]~# read-p ' please Enter your name:--> ' name
54. Please Enter your Name:-->jerry
56. [Email protected]~# Echo $name
58. Jerry
62. Read-p "Text" var1 var2 # Print hint ' text ', wait for input, store variables in var1,var2 ...
64. [Email protected]~# read-p ' What your name? ' FirstName LastName
66. What your name? Jerry Gao
68. [Email protected]~# echo "Firstname: $firstname Lastname: $lastname"
70. Firstname:jerry Lastname:gao
74. ). Read-r line # allow input with backslash
76. [Email protected]~# read Line # without the-r parameter; backslashes are not displayed
78. This was line 1. \ This was line 2.
80. [Email protected]~# echo $line
82. This was line 1. This was line 2.
86. [Email protected]~# read-r Line # with-r parameter; The backslash is displayed normally
88. This was line 1. \ This was line 2.
90. [Email protected]~# echo $line
92. This was line 1. \ This was line 2.
96. ). Read-t 5 # Specifies a read wait time of 5 seconds
98. [Email protected]~# read-t 5-p ' Your name: ' Name
100. Your Name:jerry
102. [Email protected]~# echo $name # cannot be entered if 5 seconds have not been entered
104. Jerry
108. Read-a Arrayname # Read the list of words into the arrayname array
110. [Email protected]~# read-a citys
112. BJ SH CD GZ
114. [Email protected]~# echo ${citys[*]}
116. BJ SH CD GZ
118. [Email protected]~# echo ${citys[0]}
120. BJ
124. Read-s-P "pwd:" PWD # using the-s parameter can not display the user's input
126. [Email protected]~# read-p "Enter Your Password:"-S Password
128. Enter Your Password:
130. [Email protected]~#
132. [Email protected]~# echo $PASSWORD # The password you just entered is: 1234
134. 1234
140. one). Read-n 1-p "sure? (y/n): "# Use-N to determine the number of arguments
142. [Email protected]~# read-n 1-p "is you sure? (y/n): "ANSWER
144. Is you sure? (y/n): Y
146. [Email protected]~#
148. [Email protected]~# echo-e "Your ANSWER is: $ANSWER"
150. Your ANSWER Is:y
154. ). Read-d ":" var # using: As input delimiter
156. [Email protected]~# read-d ";"-P "Enter Your name:" Name
158. Enter Your Name:jerry Gao;
160. [Email protected]~# echo-e "Your Name: $name"
162. Your Name:jerry Gao

Read in the script application:

Traversal mode one:

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1. #!/bin/bash
3. count=0
5. While Read line
6. Do
7. Echo-e "$count:--> $line"
8. count=$[count + 1]
9. Done </etc/passwd

Traverse mode Two:

[Python]View PlainCopy

1. #!/bin/bash
3. Awk-f: ' {print $1,$7} '/etc/passwd | While read user bash
4. Do
5. Echo-e "user= $user; Bash= $bash "
6. Done

Go The usage of read in the shell is detailed