47 lines
1.5 KiB
Python
47 lines
1.5 KiB
Python
# swap_link.py
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# Replace a link file with another one pointing to a new target
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#
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from pathlib import Path
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from os.path import relpath # won't be necessary with Python 3.12 thanks to walk_up arg in relative_to()
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def swap_link(lnk, tgt):
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#lnk: symbolic link to swap, str
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#tgt: target for new link, str
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lnpath = Path(lnk)
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if not lnpath.is_symlink():
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raise Exception("First argument is not a symbolic link")
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elif lnpath.exists():
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raise Exception("Link is not broken")
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tpath = Path(tgt)
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if tpath.is_symlink():
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if not tpath.exists():
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raise Exception("Target is also a broken link!")
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elif tpath.readlink().resolve() == lnpath.resolve() :
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raise Exception("Target is a link to link to be fixed...")
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tmp_suffix = 0
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tmp_prefix = 'temp'
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tmp_name = tmp_prefix + str(tmp_suffix)
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tmp_path = Path(lnpath.parent / tmp_name)
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while tmp_path.exists() or tmp_path.is_symlink():
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tmp_suffix += 1
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tmp_name = tmp_prefix + str(tmp_suffix)
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tmp_path = Path(lnk.parent / tmp_name)
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sym_path = relpath(tgt, lnk)[3:]
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try:
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tmp_path.symlink_to(sym_path)
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except Exception:
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print(f"Attempted to create tmp link: {tmp_name}")
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raise Exception("Failed to create new symlink. Check permissions!")
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try:
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lnpath.unlink()
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except Exception:
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tmp_path.unlink()
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raise Exception("Failed to remove broken link. Check permissions!")
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tmp_path.rename(lnk) |