Add stowage

bin/bin/stowage

@@ -0,0 +1,192 @@
+#!/usr/bin/env python3
+"""
+stowage
+by Keith Gaughan <https://github.com/kgaughan/>
+Stow, but in Python, and in a single file.
+Copyright (c) Keith Gaughan, 2017.
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+"""
+
+import argparse
+import fnmatch
+import os
+from os import path
+import re
+import shutil
+import sys
+
+
+def add(args):
+    target = path.realpath(args.target)
+    file_path = path.realpath(args.add)
+    package = path.realpath(args.packages[0])
+    if path.commonprefix([target, file_path]) != target:
+        print(f"error: '{args.add}' not under '{args.target}'",
+              file=sys.stderr)
+        sys.exit(1)
+    rest = file_path[len(target) + 1:]
+    dest_path = path.join(package, rest)
+    dest = path.dirname(dest_path)
+    if not path.exists(dest):
+        if args.verbose:
+            print("DIR", dest)
+        os.makedirs(dest, mode=0o755)
+    if args.verbose:
+        print("SWAP", dest_path, file_path)
+    if not args.dry_run:
+        shutil.move(file_path, dest)
+        # XXX Should really check if the symlink fails here.
+        os.symlink(dest_path, file_path)
+
+
+def install(args, is_excluded):
+    for package in args.packages:
+        if not path.isdir(package):
+            print(f"no such package: {package}; skipping", file=sys.stderr)
+            continue
+        for root, _, files in os.walk(package, followlinks=True):
+            files = [
+                filename for filename in files if not is_excluded(filename)]
+            if len(files) == 0:
+                continue
+            rest = root[len(package) + 1:]
+            dest = path.join(args.target, rest)
+            if rest != "":
+                if args.verbose:
+                    print("DIR", dest)
+                if not args.dry_run and not os.path.exists(dest):
+                    os.makedirs(dest, mode=0o755)
+            for filename in files:
+                dest_path = path.join(dest, filename)
+                if path.exists(dest_path):
+                    if args.verbose:
+                        print("SKIP", dest_path)
+                    continue
+                src_path = path.realpath(path.join(root, filename))
+                if args.verbose:
+                    print("LINK", src_path, dest_path)
+                if not args.dry_run:
+                    if path.islink(dest_path):
+                        if args.verbose:
+                            print("DANGLE", dest_path)
+                        os.unlink(dest_path)
+                    os.symlink(src_path, dest_path)
+
+
+def uninstall(args, is_excluded):
+    dirs = []
+    for package in args.packages:
+        if not path.isdir(package):
+            print(f"no such package: {package}; skipping", file=sys.stderr)
+            continue
+        for root, _, files in os.walk(package, followlinks=True):
+            files = [
+                filename for filename in files if not is_excluded(filename)]
+            if len(files) == 0:
+                continue
+            rest = root[len(package) + 1:]
+            dest = path.join(args.target, rest)
+            if rest != "":
+                dirs.append(dest)
+            for filename in files:
+                dest_path = path.join(dest, filename)
+                if path.islink(dest_path):
+                    src_path = path.realpath(path.join(root, filename))
+                    if path.realpath(dest_path) == src_path:
+                        if args.verbose:
+                            print("UNLINK", dest_path)
+                        if not args.dry_run:
+                            os.unlink(dest_path)
+                    elif args.verbose:
+                        print("SKIP", dest_path)
+                elif args.verbose:
+                    print("SKIP", dest_path)
+
+    # Delete the directories if empty.
+    for dir_path in sorted(dirs, key=len, reverse=True):
+        try:
+            if args.verbose:
+                print("RMDIR", dir_path)
+            if not args.dry_run:
+                os.rmdir(dir_path)
+        except OSError:
+            pass
+
+
+def make_argparser():
+    parser = argparse.ArgumentParser(description="A symlink farm manager.")
+    parser.add_argument("--verbose", "-v",
+                        action="store_true", help="Verbose output")
+    parser.add_argument(
+        "--target",
+        "-t",
+        default=os.path.expanduser('~'),
+        help="Target directory in which to place symlinks",
+    )
+    parser.add_argument(
+        "--exclude",
+        "-x",
+        action="append",
+        default=[],
+        metavar="GLOB",
+        help="Glob pattern of files to exclude",
+    )
+    parser.add_argument("--dry-run", "-n",
+                        action="store_true", help="Dry run.")
+
+    group = parser.add_mutually_exclusive_group(required=False)
+    group.add_argument(
+        "--uninstall",
+        "-D",
+        action="store_false",
+        dest="install",
+        help="Uninstall symlinks",
+    )
+    group.add_argument(
+        "--add", "-a", metavar="FILE", help="Stow files in a particular package"
+    )
+
+    parser.add_argument(
+        "packages", metavar="PACKAGE", nargs="+", help="Packages to install"
+    )
+    return parser
+
+
+def main():
+    parser = make_argparser()
+    args = parser.parse_args()
+    exclude = [re.compile(fnmatch.translate(pattern))
+               for pattern in args.exclude]
+
+    def is_excluded(filename):
+        return any(pattern.match(filename) for pattern in exclude)
+
+    if args.add:
+        if len(args.packages) > 1:
+            parser.error("--add only works with a single package")
+        args.add = path.normpath(path.join(args.target, args.add))
+        if not path.isfile(args.add):
+            parser.error(f"no such file: {args.add}")
+        add(args)
+    elif args.install:
+        install(args, is_excluded)
+    else:
+        uninstall(args, is_excluded)
+
+
+if __name__ == "__main__":
+    main()