46 lines
1.1 KiB
Python
Executable File
46 lines
1.1 KiB
Python
Executable File
#!/usr/bin/env python
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# Exercise 12f
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# tail command
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import sys
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import argparse
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from pathlib import Path
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parser = argparse.ArgumentParser()
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parser.add_argument("stream", default=sys.stdin, nargs="*")
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parser.add_argument("-v", "--verbose", action="store_true")
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parser.add_argument("-n", "--lines", default="10", type=str)
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args = parser.parse_args()
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res = []
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def intonum(n):
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try:
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return abs(int(n))
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except ValueError:
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print(f"tail: el número de líneas no es válido: «{n}»")
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sys.exit(1)
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def getlines(lines, n):
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lines = list(map(lambda l: l.rstrip(), lines))
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num = intonum(n)
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if n[0] == "+":
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return lines[num-1:]
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return lines[-num:]
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if isinstance(args.stream, list):
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for path in args.stream:
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lines = Path(path).open().readlines()
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header = [""] if len(res) != 0 else []
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if args.verbose:
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header += [f"==> {path} <=="]
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res += header + getlines(lines, args.lines)
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else:
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lines = args.stream.readlines()
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header = ["==> entrada estándar <=="] if args.verbose else []
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res += header + getlines(lines, args.lines)
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print("\n".join(res))
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