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@ur4ltz
Forked from YuriyNasretdinov/find.go
Created Dec 27, 2021
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package main
import (
"flag"
"log"
"os"
"syscall"
"unsafe"
"path/filepath"
"bufio"
)
var (
bufout = bufio.NewWriter(os.Stdout)
)
func clen(n []byte) int {
for i := 0; i < len(n); i++ {
if n[i] == 0 {
return i
}
}
return len(n)
}
func readdir(dir string, file string, dirfd int, pathbuf []byte) {
origbuf := make([]byte, 4096)
dh, err := syscall.Openat(dirfd, file, syscall.O_RDONLY, 0777)
if err != nil {
log.Fatalf("Could not open %s/%s: %s", dir, file, err.Error())
}
origpathbuf := pathbuf[0:0]
for {
n, errno := syscall.ReadDirent(dh, origbuf)
if errno != nil {
log.Fatalf("Could not read dirent: %s", err.Error())
}
if n <= 0 {
break // EOF
}
buf := origbuf[0:n]
for len(buf) > 0 {
dirent := (*syscall.Dirent)(unsafe.Pointer(&buf[0]))
buf = buf[dirent.Reclen:]
if dirent.Ino == 0 { // File absent in directory.
continue
}
bytes := (*[10000]byte)(unsafe.Pointer(&dirent.Name[0]))
name := bytes[0:clen(bytes[:])]
if len(name) == 1 && name[0] == '.' || len(name) == 2 && name[0] == '.' && name[1] == '.' { // Useless names
continue
}
pathbuf = append(pathbuf, dir...)
pathbuf = append(pathbuf, '/')
pathbuf = append(pathbuf, file...)
dirlen := len(pathbuf)
pathbuf = append(pathbuf, '/')
pathbuf = append(pathbuf, name...)
pathbuf = append(pathbuf, '\n')
bufout.Write(pathbuf)
if dirent.Type == syscall.DT_UNKNOWN {
st, err := os.Stat(dir + "/" + file + "/" + string(name))
if err != nil {
log.Fatalf("Could not stat: %s", err.Error())
}
if st.IsDir() {
dirent.Type = syscall.DT_DIR
}
}
if dirent.Type == syscall.DT_DIR {
readdir(string(pathbuf[0:dirlen]), string(name), dh, origpathbuf)
}
pathbuf = origpathbuf[0:0]
}
buf = origbuf[0:0]
}
syscall.Close(dh)
}
func main() {
flag.Parse()
if flag.NArg() != 1 {
log.Fatalf("Usage: %s <dir>", os.Args[0])
}
dir := flag.Arg(0)
parentDir := filepath.Dir(dir)
dh, err := os.Open(parentDir)
if err != nil {
log.Fatalf("Could not open dir: %s", err.Error())
}
pathbuf := make([]byte, 16 * 1024)
readdir(parentDir, filepath.Base(dir), int(dh.Fd()), pathbuf)
bufout.Flush()
}
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