Golang file Operations

 
   Package Main

Import (

"Bytes"

"FMT"

"IO"

"OS"

)

var file *os. File = &os. file{}

var filebuf *bytes. Buffer = bytes. Newbufferstring ("")

Func Main () {

var err error

File, err = OS. OpenFile ("TestData.txt", OS. O_create|os. O_append|os. O_rdwr|os. O_trunc, OS. Modeperm|os. Modetemporary)
    Os. O_trunc empty files that already exist

If err! = Nil {

Panic (ERR)

}

Filebuf.writestring (FMT. Sprintf ("%d", 1000))

Filebuf.writestring ("\ n")

Filebuf.writestring ("Hello World")

Io. WriteString (file, filebuf.string ())

Defer file. Close ()

}
Open all kinds of existing and nonexistent files in various ways, how to do it depends on flag and perm
Flag selectable value (mask)

o_rdonly int = Syscall. O_rdonly//Read-only

o_wronly int = Syscall. O_wronly//write only

o_rdwr int = Syscall. O_RDWR//Read/write

o_append int = Syscall. O_append//Append at end of file, open cursor at end of file

o_create int = Syscall. O_creat//If it does not exist, create

o_excl int = Syscall. O_EXCL//With o_create to form a new file feature that requires that the file must not exist

O_sync int = Syscall. O_sync//Sync mode open, no cache, so write content directly to the hard disk, the system power down the file content has certain guarantee

O_trunc int = Syscall. O_trunc//Open and empty files

  FileMode is Unix's permission bit: reference: http://www.ibm.com/developerworks/cn/aix/library/au-speakingunix4
  

Golang file Operations