Files
postmarketos-mkinitfs/internal/misc/misc.go
2023-02-18 11:22:25 -08:00

125 lines
2.7 KiB
Go

// Copyright 2022 Clayton Craft <clayton@craftyguy.net>
// SPDX-License-Identifier: GPL-3.0-or-later
package misc
import (
"fmt"
"log"
"os"
"path/filepath"
"strings"
"time"
"golang.org/x/sys/unix"
)
// Converts a relative symlink target path (e.g. ../../lib/foo.so), that is
// absolute path
func RelativeSymlinkTargetToDir(symPath string, dir string) (string, error) {
var path string
oldWd, err := os.Getwd()
if err != nil {
log.Print("Unable to get current working dir")
return path, err
}
if err := os.Chdir(dir); err != nil {
log.Print("Unable to change to working dir: ", dir)
return path, err
}
path, err = filepath.Abs(symPath)
if err != nil {
log.Print("Unable to resolve abs path to: ", symPath)
return path, err
}
if err := os.Chdir(oldWd); err != nil {
log.Print("Unable to change to old working dir")
return path, err
}
return path, nil
}
func FreeSpace(path string) (uint64, error) {
var stat unix.Statfs_t
unix.Statfs(path, &stat)
size := stat.Bavail * uint64(stat.Bsize)
return size, nil
}
// Merge the contents of "b" into "a", overwriting any previously existing keys
// in "a"
func Merge(a map[string]string, b map[string]string) {
for k, v := range b {
a[k] = v
}
}
// Removes duplicate entries from the given string slice and returns a slice
// with the unique values
func RemoveDuplicates(in []string) (out []string) {
// use a map to "remove" duplicates. the value in the map is totally
// irrelevant
outMap := make(map[string]bool)
for _, s := range in {
if ok := outMap[s]; !ok {
outMap[s] = true
}
}
out = make([]string, 0, len(outMap))
for k := range outMap {
out = append(out, k)
}
return
}
// Prints the execution time of a function, not meant to be very
// sensitive/accurate, but good enough to gauge rough run times.
// Meant to be called as:
//
// defer misc.TimeFunc(time.Now(), "foo")
func TimeFunc(start time.Time, name string) {
elapsed := time.Since(start)
log.Printf("%s completed in: %s", name, elapsed)
}
func getKernelReleaseFile() (string, error) {
files, _ := filepath.Glob("/usr/share/kernel/*/kernel.release")
// only one kernel flavor supported
if len(files) != 1 {
return "", fmt.Errorf("only one kernel release/flavor is supported, found: %q", files)
}
return files[0], nil
}
func GetKernelVersion() (string, error) {
var version string
releaseFile, err := getKernelReleaseFile()
if err != nil {
return version, err
}
contents, err := os.ReadFile(releaseFile)
if err != nil {
return version, err
}
return strings.TrimSpace(string(contents)), nil
}
// Exists tests if the given file/dir exists or not
func Exists(file string) bool {
if _, err := os.Stat(file); err == nil {
return true
}
return false
}