111 lines
2.1 KiB
Go
111 lines
2.1 KiB
Go
package util
|
|
|
|
import (
|
|
"bufio"
|
|
"bytes"
|
|
"io"
|
|
"os"
|
|
)
|
|
|
|
// WriteFile writes a given byte array to the given path.
|
|
func WriteFile(b []byte, p string) error {
|
|
f, err := os.Create(p)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = f.Write(b)
|
|
defer f.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// ReadFile reads a byte array from a given path.
|
|
func ReadFile(p string) ([]byte, error) {
|
|
f, err := os.Open(p)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
var result []byte
|
|
buf := make([]byte, 1024)
|
|
for {
|
|
n, err := f.Read(buf)
|
|
// check for a non EOF error
|
|
if err != nil && err != io.EOF {
|
|
return nil, err
|
|
}
|
|
// n==0 when there are no chunks left to read
|
|
if n == 0 {
|
|
defer f.Close()
|
|
break
|
|
}
|
|
result = append(result, buf[:n]...)
|
|
}
|
|
return result, nil
|
|
}
|
|
|
|
// CopyFile reads the file at the input path, and write
|
|
// it to the output path.
|
|
func CopyFile(inPath string, outPath string) error {
|
|
inB, err := ReadFile(inPath)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := WriteFile(inB, outPath); err != nil {
|
|
return err
|
|
} else {
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// ReadNLines reads the first N lines from a file as a single byte array
|
|
func ReadNLines(filename string, n int) ([]byte, error) {
|
|
file, err := os.Open(filename)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer file.Close()
|
|
|
|
var buffer bytes.Buffer
|
|
scanner := bufio.NewScanner(file)
|
|
for i := 0; i < 3 && scanner.Scan(); i++ {
|
|
buffer.Write(scanner.Bytes())
|
|
buffer.WriteByte('\n')
|
|
}
|
|
|
|
if err := scanner.Err(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return buffer.Bytes(), nil
|
|
}
|
|
|
|
// ReadLineRange reads a file in a given range of lines
|
|
func ReadLineRange(filename string, start int, end int) ([]byte, error) {
|
|
file, err := os.Open(filename)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer file.Close()
|
|
|
|
var buffer bytes.Buffer
|
|
scanner := bufio.NewScanner(file)
|
|
i := 0
|
|
for scanner.Scan() {
|
|
if i >= start && (i <= end || end == -1) {
|
|
buffer.Write(scanner.Bytes())
|
|
buffer.WriteByte('\n')
|
|
}
|
|
if i > end && end != -1 {
|
|
break
|
|
}
|
|
i++
|
|
}
|
|
|
|
if err := scanner.Err(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return buffer.Bytes(), nil
|
|
}
|