1. Common methods of path

a. Path module (path)

Encapsulates various path related operations

Like Buffer, the path in NodeJS is also a special module

The difference is that the Buffer module has been added to Global,   Therefore, manual import is not required

The Path module was not added to Global,   Therefore, manual import is required

b. Get the last part of the path

path.basename(path[, ext])

let path = require("path");

// basename is used to get the last component of the path
// let res = path.basename('/a/b/c/d/index.html');//index.html
// let res = path.basename('/a/b/c/d'); //d
let res = path.basename('/a/b/c/d/index.html', ".html"); //index
console.log(res);

c. Get path

path.dirname(path)

// dirname is used to get the directory in the path, that is, the content except the last part
// let res = path.dirname('/a/b/c/d/index.html'); // /a/b/c/d
let res = path.dirname('/a/b/c/d'); // /a/b/c
console.log(res);

 

d. Get extension name

path.extname(path)

// extname is used to get the extension of the last component in the path
// let res = path.extname('/a/b/c/d/index.html'); //.html
let res = path.extname('/a/b/c/d'); // 
console.log(res);

e. Determine whether it is an absolute path

path.isAbsolute(path)

isAbsolute is used to determine whether the path is an absolute path

Note:

Differentiated operating system

In the Linux operating system, / starts with an absolute path

In the Windows operating system, the drive letter begins with an absolute path

In the Linux operating system, the path separator is a left slash  /

In the Windows operating system, the path separator is a right slash  \

// let res = path.isAbsolute('/a/b/c/d/index.html'); // true
// let res = path.isAbsolute('./a/b/c/d/index.html'); // false
// let res = path.isAbsolute('c:\\a\\b\\c\\d\\index.html'); // true
let res = path.isAbsolute('a\\b\\c\\d\\index.html'); // false
console.log(res);

f. Gets the current operating system path separator

path.delimiter    (windows is)\   Linux (yes /)

// path.delimiter is used to obtain the delimiter of the current operating system environment variable
// If you are running in the Linux operating system, you will get:
// If it is running in the Windows operating system, the obtained is;
console.log(path.delimiter); // ;

g. Gets the current path environment variable separator

path.sep is used to obtain the separator of the path in the current operating system

If you are running in the Linux operating system, what you get is   Left slash  /

If you are running in the Windows operating system, you will get   Right slash  \

path.sep    (used in windows);   (used in linux:)

console.log(path.sep); // \

2.path other methods

i. Path formatting:

path.parse(path):   Used to convert paths to objects

let obj = path.parse("/a/b/c/d/index.html");
console.log(obj);

 

path.format(pathObject):   Used to convert objects to paths

let obj = {
    root: '/',
    dir: '/a/b/c/d',
    base: 'index.html',
    ext: '.html',
    name: 'index'
};
let str = path.format(obj);
console.log(str);

 

ii. Splicing path:

path.join([...paths]):   For splicing paths

Note:

• If / is not added to the parameter,   Then the method is automatically added
• If there is,   The path will be automatically generated according to the previous parameters,   Go to the upper level path

 

// let str = path.join("/a/b", "c"); // /a/b/c
// let str = path.join("/a/b", "/c"); // /a/b/c
// let str = path.join("/a/b", "/c", "../"); // /a/b/c --> /a/b
let str = path.join("/a/b", "/c", "../../"); // /a/b/c --> /a
console.log(str);

iii. standardization path:

path.normalize(path):   Used to normalize paths

let res = path.normalize("/a//b///cd/index.html");
console.log(res); // \a\b\c\d\index.html

iv. calculate relative path:

path.relative(from,   to):   Used to calculate relative paths

First parameter:  / data/orandea/test/aaa

Second parameter:  / data/orandea/impl/bbb

/**
 * /data/orandea/test/aaa --> ../  --> /data/orandea/test
 * /data/orandea/test --> ../ --> /data/orandea
 * ..\..\impl\bbb
 */
let res = path.relative('/data/orandea/test/aaa', '/data/orandea/impl/bbb');
console.log(res); // ..\..\impl\bbb

v. Resolution path:

path.resolve([...paths]):   Used to resolve paths

Note:   If the following parameter is an absolute path,   Then the previous parameters will be ignored

// let res = path.resolve('/foo/bar', './baz'); // /foo/bar/baz
// let res = path.resolve('/foo/bar', '../baz'); // /foo/baz
let res = path.resolve('/foo/bar', '/baz'); // /baz
console.log(res);