Go Package os
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External
Internal
Overview
Reading and Writing an Entire File in/from Memory
Read with ReadFile()
To read the content of an entire file into a byte slice:
bs, err := os.ReadFile("/Users/ovidiu/tmp/test.txt")
os.ReadFile()
closes the file after use.
Write with WriteFile()
To write in-memory data into a file:
s := "This\nis multi-line\nfile\ncontent\n"
err := os.WriteFile("/Users/ovidiu/tmp/test2.txt", []byte(s), 0777)
os.WriteFile()
closes the file after use.
Sequentially Reading and Writing Byte Arrays
Move to File Operations in Go.
Reading
Open the file with os.Open()
and then use file package file.Read()
to read into a byte slice.
bs := make([]byte, 10)
f, err := os.Open("/Users/ovidiu/tmp/test.txt")
if err != nil {
// ...
f.Close()
return
}
for {
cnt, err := f.Read(bs)
if err != nil {
fmt.Println(err)
f.Close()
return
}
fmt.Println("read ", cnt, " bytes")
}
The file must be explicitly closed after use.
Writing
To write in-memory data into a file:
s := "This\nis multi-line\nfile\ncontent\n"
err := os.WriteFile("/Users/ovidiu/tmp/test2.txt", []byte(s), 0777)
The file must be explicitly closed after use.
TO DEPLETE
Functions
os.Open()
Works with files and directories.
os.Create()
os.File
os.File Methods
FileInfo
FileInfo Methods
- Size()
os.Args
os.Args is a string slice that holds the command-line arguments, starting with the program name. For more details on how to use see: