go.mway.dev/x@v0.0.0-20240520034138-950aede9a3fb/path/filepath/ancestors.go (about)

     1  // Copyright (c) 2024 Matt Way
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to
     5  // deal in the Software without restriction, including without limitation the
     6  // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     7  // sell copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    18  // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
    19  // IN THE THE SOFTWARE.
    20  
    21  // Package filepath provides filepath-related utilities.
    22  package filepath
    23  
    24  import (
    25  	"os"
    26  	"path/filepath"
    27  	"strings"
    28  )
    29  
    30  const _sep = string(os.PathSeparator)
    31  
    32  // Ancestors returns a list of all ancestor paths contained within path.
    33  func Ancestors(path string) []string {
    34  	path = filepath.Clean(path)
    35  	switch path {
    36  	case "", ".", "..", _sep:
    37  		return nil
    38  	}
    39  
    40  	var offset int
    41  	if path[0] == _sep[0] {
    42  		offset++
    43  	}
    44  
    45  	size := strings.Count(path, "/") - offset
    46  	if size == 0 {
    47  		return nil
    48  	}
    49  
    50  	paths := make([]string, 0, strings.Count(path, "/"))
    51  	for {
    52  		if path = filepath.Dir(path); path == "." || path == _sep {
    53  			break
    54  		}
    55  		paths = append(paths, path)
    56  	}
    57  	return paths
    58  }