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authorOndřej Surý <ondrej@sury.org>2011-04-26 09:55:32 +0200
committerOndřej Surý <ondrej@sury.org>2011-04-26 09:55:32 +0200
commit7b15ed9ef455b6b66c6b376898a88aef5d6a9970 (patch)
tree3ef530baa80cdf29436ba981f5783be6b4d2202b /src/pkg/path/filepath/path.go
parent50104cc32a498f7517a51c8dc93106c51c7a54b4 (diff)
downloadgolang-7b15ed9ef455b6b66c6b376898a88aef5d6a9970.tar.gz
Imported Upstream version 2011.04.13upstream/2011.04.13
Diffstat (limited to 'src/pkg/path/filepath/path.go')
-rw-r--r--src/pkg/path/filepath/path.go128
1 files changed, 104 insertions, 24 deletions
diff --git a/src/pkg/path/filepath/path.go b/src/pkg/path/filepath/path.go
index 414df7d20..de673a725 100644
--- a/src/pkg/path/filepath/path.go
+++ b/src/pkg/path/filepath/path.go
@@ -8,12 +8,16 @@
package filepath
import (
+ "bytes"
"os"
"sort"
"strings"
)
-// BUG(niemeyer): Package filepath does not yet work on Windows.
+const (
+ SeparatorString = string(Separator)
+ ListSeparatorString = string(ListSeparator)
+)
// Clean returns the shortest path name equivalent to path
// by purely lexical processing. It applies the following rules
@@ -38,36 +42,39 @@ func Clean(path string) string {
return "."
}
- rooted := path[0] == Separator
- n := len(path)
+ rooted := IsAbs(path)
// Invariants:
// reading from path; r is index of next byte to process.
// writing to buf; w is index of next byte to write.
// dotdot is index in buf where .. must stop, either because
// it is the leading slash or it is a leading ../../.. prefix.
+ prefix := volumeName(path)
+ path = path[len(prefix):]
+ n := len(path)
buf := []byte(path)
r, w, dotdot := 0, 0, 0
if rooted {
+ buf[0] = Separator
r, w, dotdot = 1, 1, 1
}
for r < n {
switch {
- case path[r] == Separator:
+ case isSeparator(path[r]):
// empty path element
r++
- case path[r] == '.' && (r+1 == n || path[r+1] == Separator):
+ case path[r] == '.' && (r+1 == n || isSeparator(path[r+1])):
// . element
r++
- case path[r] == '.' && path[r+1] == '.' && (r+2 == n || path[r+2] == Separator):
+ case path[r] == '.' && path[r+1] == '.' && (r+2 == n || isSeparator(path[r+2])):
// .. element: remove to last separator
r += 2
switch {
case w > dotdot:
// can backtrack
w--
- for w > dotdot && buf[w] != Separator {
+ for w > dotdot && !isSeparator(buf[w]) {
w--
}
case !rooted:
@@ -90,7 +97,7 @@ func Clean(path string) string {
w++
}
// copy element
- for ; r < n && path[r] != Separator; r++ {
+ for ; r < n && !isSeparator(path[r]); r++ {
buf[w] = path[r]
w++
}
@@ -103,7 +110,7 @@ func Clean(path string) string {
w++
}
- return string(buf[0:w])
+ return prefix + string(buf[0:w])
}
// ToSlash returns the result of replacing each separator character
@@ -112,7 +119,7 @@ func ToSlash(path string) string {
if Separator == '/' {
return path
}
- return strings.Replace(path, string(Separator), "/", -1)
+ return strings.Replace(path, SeparatorString, "/", -1)
}
// FromSlash returns the result of replacing each slash ('/') character
@@ -121,7 +128,7 @@ func FromSlash(path string) string {
if Separator == '/' {
return path
}
- return strings.Replace(path, "/", string(Separator), -1)
+ return strings.Replace(path, "/", SeparatorString, -1)
}
// SplitList splits a list of paths joined by the OS-specific ListSeparator.
@@ -129,7 +136,7 @@ func SplitList(path string) []string {
if path == "" {
return []string{}
}
- return strings.Split(path, string(ListSeparator), -1)
+ return strings.Split(path, ListSeparatorString, -1)
}
// Split splits path immediately following the final Separator,
@@ -137,7 +144,10 @@ func SplitList(path string) []string {
// If there are no separators in path, Split returns an empty base
// and file set to path.
func Split(path string) (dir, file string) {
- i := strings.LastIndex(path, string(Separator))
+ i := len(path) - 1
+ for i >= 0 && !isSeparator(path[i]) {
+ i--
+ }
return path[:i+1], path[i+1:]
}
@@ -146,7 +156,7 @@ func Split(path string) (dir, file string) {
func Join(elem ...string) string {
for i, e := range elem {
if e != "" {
- return Clean(strings.Join(elem[i:], string(Separator)))
+ return Clean(strings.Join(elem[i:], SeparatorString))
}
}
return ""
@@ -157,7 +167,7 @@ func Join(elem ...string) string {
// in the final element of path; it is empty if there is
// no dot.
func Ext(path string) string {
- for i := len(path) - 1; i >= 0 && path[i] != Separator; i-- {
+ for i := len(path) - 1; i >= 0 && !isSeparator(path[i]); i-- {
if path[i] == '.' {
return path[i:]
}
@@ -165,6 +175,77 @@ func Ext(path string) string {
return ""
}
+// EvalSymlinks returns the path name after the evaluation of any symbolic
+// links.
+// If path is relative it will be evaluated relative to the current directory.
+func EvalSymlinks(path string) (string, os.Error) {
+ const maxIter = 255
+ originalPath := path
+ // consume path by taking each frontmost path element,
+ // expanding it if it's a symlink, and appending it to b
+ var b bytes.Buffer
+ for n := 0; path != ""; n++ {
+ if n > maxIter {
+ return "", os.NewError("EvalSymlinks: too many links in " + originalPath)
+ }
+
+ // find next path component, p
+ i := strings.IndexRune(path, Separator)
+ var p string
+ if i == -1 {
+ p, path = path, ""
+ } else {
+ p, path = path[:i], path[i+1:]
+ }
+
+ if p == "" {
+ if b.Len() == 0 {
+ // must be absolute path
+ b.WriteRune(Separator)
+ }
+ continue
+ }
+
+ fi, err := os.Lstat(b.String() + p)
+ if err != nil {
+ return "", err
+ }
+ if !fi.IsSymlink() {
+ b.WriteString(p)
+ if path != "" {
+ b.WriteRune(Separator)
+ }
+ continue
+ }
+
+ // it's a symlink, put it at the front of path
+ dest, err := os.Readlink(b.String() + p)
+ if err != nil {
+ return "", err
+ }
+ if IsAbs(dest) {
+ b.Reset()
+ }
+ path = dest + SeparatorString + path
+ }
+ return Clean(b.String()), nil
+}
+
+// Abs returns an absolute representation of path.
+// If the path is not absolute it will be joined with the current
+// working directory to turn it into an absolute path. The absolute
+// path name for a given file is not guaranteed to be unique.
+func Abs(path string) (string, os.Error) {
+ if IsAbs(path) {
+ return path, nil
+ }
+ wd, err := os.Getwd()
+ if err != nil {
+ return "", err
+ }
+ return Join(wd, path), nil
+}
+
// Visitor methods are invoked for corresponding file tree entries
// visited by Walk. The parameter path is the full path of f relative
// to root.
@@ -199,7 +280,7 @@ func walk(path string, f *os.FileInfo, v Visitor, errors chan<- os.Error) {
// a list of sorted directory entries.
// Copied from io/ioutil to avoid the circular import.
func readDir(dirname string) ([]*os.FileInfo, os.Error) {
- f, err := os.Open(dirname, os.O_RDONLY, 0)
+ f, err := os.Open(dirname)
if err != nil {
return nil, err
}
@@ -250,21 +331,20 @@ func Base(path string) string {
return "."
}
// Strip trailing slashes.
- for len(path) > 0 && path[len(path)-1] == Separator {
+ for len(path) > 0 && isSeparator(path[len(path)-1]) {
path = path[0 : len(path)-1]
}
// Find the last element
- if i := strings.LastIndex(path, string(Separator)); i >= 0 {
+ i := len(path) - 1
+ for i >= 0 && !isSeparator(path[i]) {
+ i--
+ }
+ if i >= 0 {
path = path[i+1:]
}
// If empty now, it had only slashes.
if path == "" {
- return string(Separator)
+ return SeparatorString
}
return path
}
-
-// IsAbs returns true if the path is absolute.
-func IsAbs(path string) bool {
- return len(path) > 0 && path[0] == Separator
-}