From 1bd2d4e31b739586cf91ddfe65349f79298af013 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Mon, 23 Jan 2017 01:11:45 -0500 Subject: man: add systemd.environment-generator(7) with two examples v2: - add example files to EXTRA_DIST v3: - rework for the new scheme where nothing is written to disk v4: - use separate dirs for system and user env generators --- man/90-rearrange-path.py | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100755 man/90-rearrange-path.py (limited to 'man/90-rearrange-path.py') diff --git a/man/90-rearrange-path.py b/man/90-rearrange-path.py new file mode 100755 index 0000000000..c6ff32210f --- /dev/null +++ b/man/90-rearrange-path.py @@ -0,0 +1,40 @@ +#!/usr/bin/python3 + +""" + +Proof-of-concept systemd environment generator that makes sure that bin dirs +are always after matching sbin dirs in the path. +(Changes /sbin:/bin:/foo/bar to /bin:/sbin:/foo/bar.) + +This generator shows how to override the configuration possibly created by +earlier generators. It would be easier to write in bash, but let's have it +in Python just to prove that we can, and to serve as a template for more +interesting generators. + +""" + +import os +import pathlib + +def rearrange_bin_sbin(path): + """Make sure any pair of …/bin, …/sbin directories is in this order + + >>> rearrange_bin_sbin('/bin:/sbin:/usr/sbin:/usr/bin') + '/bin:/sbin:/usr/bin:/usr/sbin' + """ + items = [pathlib.Path(p) for p in path.split(':')] + for i in range(len(items)): + if 'sbin' in items[i].parts: + ind = items[i].parts.index('sbin') + bin = pathlib.Path(*items[i].parts[:ind], 'bin', *items[i].parts[ind+1:]) + if bin in items[i+1:]: + j = i + 1 + items[i+1:].index(bin) + items[i], items[j] = items[j], items[i] + return ':'.join(p.as_posix() for p in items) + +if __name__ == '__main__': + path = os.environ['PATH'] # This should be always set. + # If it's not, we'll just crash, we is OK too. + new = rearrange_bin_sbin(path) + if new != path: + print('PATH={}'.format(new)) -- cgit v1.2.1