In addition to Weibo, there is also WeChat
Please pay attention
WeChat public account
Shulou
2025-04-04 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Servers >
Share
Shulou(Shulou.com)06/02 Report--
content points
Condition test:
file test
integer test
String vs. Logic Test
If statement:
If single branch statement
If double branch statement
If multi-branch statement
I. Conditional test:
text command: tests whether a specific expression is true. When the condition is true, the return value of the test statement is 0, otherwise it is other values.
Format 1: test conditional expression Format 2:[conditional expression]
1. Document testing
file comparison
[operator file or directory]
Common test operator L:
-d: test whether it is a directory-e: test whether a directory or file exists-f: test whether it is a file-X: test whether the current user has execution permission-r: test whether the current user has read permission-W: test whether the current user has write permission
2, integer test:
Compare integer values:
Method 1: [integer 1 operator integer 2] Method 2: [$ (integer 1) operator integer 2] Method 3: [integer 1 operator integer 2]
Common test operators:
-eq: equal to-ne: not equal to-It: less than-gt: greater than-le: less than or equal to-ge: greater than or equal to
Test whether the file exists or not, if it does not exist, create it
Details of use:
3. String and logic test:
string comparison
Format 1:[String 1 = String 2 ] [String 1 != String 2 ] Format 2:[-z string]
Common test operators:
=: string content is the same! =: String content is different-z: String content is empty
Logic test:
Format 1:[Expression 1 ] Operator [Expression 2 ]... Format 2: Command 1 Operator Command 2...
Common logical test operators
-a or &&: logical and, meaning "and"-o or||: logical or, meaning "or"!: logical no
If statement:
if single branch
If double branching:
If multiple branches:
Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.
Views: 0
*The comments in the above article only represent the author's personal views and do not represent the views and positions of this website. If you have more insights, please feel free to contribute and share.
Continue with the installation of the previous hadoop.First, install zookooper1. Decompress zookoope
"Every 5-10 years, there's a rare product, a really special, very unusual product that's the most un
© 2024 shulou.com SLNews company. All rights reserved.