Beego/utils/file.go

80 lines
1.4 KiB
Go

package utils
import (
"bufio"
"errors"
"io"
"os"
"path/filepath"
"regexp"
)
func SelfPath() string {
path, _ := filepath.Abs(os.Args[0])
return path
}
func SelfDir() string {
return filepath.Dir(SelfPath())
}
// FileExists reports whether the named file or directory exists.
func FileExists(name string) bool {
if _, err := os.Stat(name); err != nil {
if os.IsNotExist(err) {
return false
}
}
return true
}
// search a file in paths.
// this is offen used in search config file in /etc ~/
func LookFile(filename string, paths ...string) (fullpath string, err error) {
for _, path := range paths {
if fullpath = filepath.Join(path, filename); FileExists(fullpath) {
return
}
}
err = errors.New(fullpath + " not found in paths")
return
}
// like command grep -E
// for example: GrepE(`^hello`, "hello.txt")
// \n is striped while read
func GrepE(patten string, filename string) (lines []string, err error) {
re, err := regexp.Compile(patten)
if err != nil {
return
}
fd, err := os.Open(filename)
if err != nil {
return
}
lines = make([]string, 0)
reader := bufio.NewReader(fd)
prefix := ""
for {
byteLine, isPrefix, er := reader.ReadLine()
if er != nil && er != io.EOF {
return nil, er
}
line := string(byteLine)
if isPrefix {
prefix += line
continue
}
line = prefix + line
if re.MatchString(line) {
lines = append(lines, line)
}
if er == io.EOF {
break
}
}
return lines, nil
}