48 lines
1.5 KiB
Python
Executable File
48 lines
1.5 KiB
Python
Executable File
#! /usr/bin/env python
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# 1) Regular Expressions Test
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#
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# Read a file of (extended per egrep) regular expressions (one per line),
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# and apply those to all files whose names are listed on the command line.
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# Basically, an 'egrep -f' simulator. Test it with 20 "vt100" patterns
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# against a five /etc/termcap files. Tests using more elaborate patters
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# would also be interesting. Your code should not break if given hundreds
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# of regular expressions or binary files to scan.
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# This implementation:
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# - combines all patterns into a single one using ( ... | ... | ... )
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# - reads patterns from stdin, scans files given as command line arguments
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# - produces output in the format <file>:<lineno>:<line>
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# - is only about 2.5 times as slow as egrep (though I couldn't run
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# Tom's test -- this system, a vanilla SGI, only has /etc/terminfo)
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import string
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import sys
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import re
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def main():
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pats = list(map(chomp, sys.stdin.readlines()))
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bigpat = '(' + '|'.join(pats) + ')'
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prog = re.compile(bigpat)
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for file in sys.argv[1:]:
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try:
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fp = open(file, 'r')
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except IOError as msg:
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print("%s: %s" % (file, msg))
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continue
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lineno = 0
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while 1:
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line = fp.readline()
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if not line:
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break
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lineno = lineno + 1
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if prog.search(line):
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print("%s:%s:%s" % (file, lineno, line), end=' ')
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def chomp(s):
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return s.rstrip('\n')
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if __name__ == '__main__':
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main()
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