Golang filesystem: Difference between revisions
From wikinotes
Line 89: | Line 89: | ||
<syntaxhighlight lang="go"> | <syntaxhighlight lang="go"> | ||
import "path" | import "path" | ||
filename := path.Base("/home/will/.vim") // ".vim" (basename) | |||
filepath := path.Clean("./..//will/Downloads") // "/home/will/Downloads" | |||
filepath := path.Join("/a/b", "c", "d") // "/a/b/c/d" | |||
filepath := path.Dir("/home/will/.zshrc") // "/home/will" | |||
filepath := path.Ext("foo.txt") // ".txt" | |||
isTrue := path.IsAbs // true | |||
</syntaxhighlight> | </syntaxhighlight> | ||
</blockquote><!-- Filepaths --> | </blockquote><!-- Filepaths --> |
Revision as of 16:57, 18 June 2022
Documentation
os
(os-specific filesystem operations)https://pkg.go.dev/os@go1.18.3 path
(filepaths)https://pkg.go.dev/path@go1.18.3 io/ioutil
(read/write)https://pkg.go.dev/io/ioutil@go1.18.3 io/fs
(filesystem)https://pkg.go.dev/io/fs@go1.18.3
Errors
require "errors" require "os" require "io/fs" _, err := os.Stat("foo.bar") if errors.Is(err, fs.ErrExist) {...} if errors.Is(err, fs.ErrNotExist) {...} if errors.Is(err, fs.ErrPermission) {...} if errors.Is(err, fs.ErrPermission) {...}The old method defines
Is${N}
functions to test for variousos
package errors.
require "os" // example filesystem operations that create errors info, err := os.Stat("foo.bar") fd, err := os.Create("/etc/foo") // example error checks if os.IsExist(err) {...} if os.IsNotExist(err) {...} if os.IsPermission(err) {...}
Locations
// XDG spec dir, err := os.UserHomeDir() dir, err := os.UserConfigDir() dir, err := os.UserCacheDir()
Filesystem
import "os" import "errors" // check if file exists if _, err := os.Stat("/var/foo.txt"); errors.Is(err, fs.ErrNotExist) { fmt.Println("file does not exist!") } dir, err := os.Getwd() err := os.Chmod("foo.txt", 0644) err := os.Chown("foo.txt", -1, -1) // '-1' means do not change uid/gid err := os.Chown("foo.txt", 1000, -1) // set uid '1000' as owner err := os.Link("/var/foo", "/var/bar") // hardlink err := os.Symlink("/var/foo", "/var/bar") // symlink err := os.Mkdir("/var/foo") // create directory (non recursively) err := os.MkdirAll("/var/foo/bar/baz") // creates directory (recursively) err := os.Remove("/var/tmp/foo.bar") err := os.RemoveAll("/var/tmp/foo") err := os.Rename("a", "b")
Filepaths
import "path" filename := path.Base("/home/will/.vim") // ".vim" (basename) filepath := path.Clean("./..//will/Downloads") // "/home/will/Downloads" filepath := path.Join("/a/b", "c", "d") // "/a/b/c/d" filepath := path.Dir("/home/will/.zshrc") // "/home/will" filepath := path.Ext("foo.txt") // ".txt" isTrue := path.IsAbs // true
Files
For more details, see golang input/output
File.Create File.NewFile File.Open File.Write File.WriteString File.Stat File.FileInforequire "os" os.WriteFile("/var/tmp/foo.txt", []byte("abc"), 0644) conts, err := os.ReadFile("/var/tmp/foo.txt")
Temporary Files/Directories
Temporary Directories
// creates tempdir, // '*' in filename is placement of random str // you must delete! path, err := os.MkdirTemp("/var/tmp", "cache-*") defer os.RemoveAll(path)File.CreateTemp