Golang mimics the tail command, displaying the file contents of the specified number of lines at the end of the file

This is a creation in Article, where the information may have evolved or changed. The project needs to implement the ability to read the specified number of rows at the end of the file (similar to the tail command), and then see the implementation of the tail command. Then use the go language to follow the idea of writing a bit. The real-time output function of the log can be implemented in conjunction with Https://github.com/fsnotify/fsnotify. Similar to ' tail-f xxx.log ' effect ' package mainimport ("Bufio" "bytes" "io" "Log" "OS" "strings") func main () {lines: = Int64 ($) file , err: = OS. Open ("C:\\users\\administrator\\desktop\\test.log") if err! = Nil {log. PRINTLN (Err) Return}fileinfo, _: = file. Stat () buf: = Bufio. Newreader (file) Offset: = fileinfo.size ()% 8192data: = make ([]byte, 8192)//row of data totalbyte: = Make ([][][]byte, 0) readLine S: = Int64 (0) for I: = Int64 (0); I <= fileinfo.size ()/8192; I++{readbyte: = Make ([][]byte, 0)//read a page of data file. Seek (Fileinfo.size ()-Offset-8192*i, Io. Seekstart) data = make ([]byte, 8192) n, err: = buf. Read (data) If Err = = Io. EOF {if strings. Trimspace (String (bytes. Trim (data, "\x00")))! = "" {readlines++readbyte = append (readbyte, data) Totalbyte = Append (Totalbyte, readbyte)}if ReadLines > Lines{break}continue}if Err! = Nil {log. Println ("Read File Error:", err) RetuRn}strs: = Strings. Split (String (data[:n]), "\ n") If Len (strs) = = 1{b: = bytes. Trim ([]byte (Strs[0]), "\x00") If Len (b) = = 0{continue}}if (readlines + int64 (len (STRs))) > Lines{strs = Strs[int64 (Len ( STRs))-lines+readlines:]}for J:=0;j<len (STRs); j++{readbyte = append (readbyte, bytes. Trim ([]byte (strs[j]+ "\ n"), "\x00"))}readbyte[len (ReadByte)-1] = bytes. Trimsuffix (Readbyte[len (ReadByte)-1], []byte ("\ n")) Totalbyte = append (Totalbyte, readbyte) ReadLines + = Int64 (Len ( STRs)) If readlines >= lines{break}}totalbyte = Reversebytearray (totalbyte) log. Println (ByteArrayToString (totalbyte))}func Reversebytearray (s [][][]byte) [][][]byte {for from], to: = 0, Len (s)-1; from & Lt to; From, to = From+1, to-1 {S[from], s[to] = s[to], S[from]}return s}func bytearraytostring (buf [][][]byte) string {str: = ma Ke ([]string, 0) for _, V: = Range Buf {For _, VV: = range v {str = append (str, string (VV))}}return strings. Join (str, "")} "if there are inappropriate places, please correct me \x00 is to remove the invalid content in the file, if the log output is normal, you can delete the relevant code 519 reads