Re^4: seeking improvement in my smiple program using regular expression

the following may do the trick:

s{ ((?: [^ ]+ \s+ ){17}) \d{1,3} (\s+ \d+) $} {$1$count$2}x;
[download]

just a few points, some of which have been made before...

the complemented character set [^ ] is not the same as \S (that's a capital-S) because it includes the tab, newline, etc., characters -- in fact, all characters (including whitespace characters) except space;
because the pattern is anchored at the end of the string, the (?: [^ ]+ \s+ ){17} repetitions may be preceded by more (?: [^ ]+ \s+ ) repetitions or by anything else;
therefore, what you are really saying is that you want the \d{1,3} you're replacing to be preceded by at least 17 repetitions of (?: [^ ]+ \s+ ), then by anything else;
it may be worth considering if this ``17 repetitions'' business is really what you need;
if it isn't, the regex may simplify further to s{ \d{1,3} (?= \s+ \d+ $)} {$count}x;

all these regexes are untested.

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Re^5: seeking improvement in my smiple program using regular expression by BrowserUk (Patriarch) on Aug 06, 2007 at 06:06 UTC
Repeated captures do not work. Only the last repetition actually captures anything. Contrast: `my @captures = 'abcde' =~ m[(.){3}]; print "@captures";; c` [download] with `my @captures = 'abcde' =~ m[(.)(.)(.)];; print "@captures";; a b c` [download] and `'abcde' =~ m[(.){3}] and print "$1,$2,$3";; Use of uninitialized value in concatenation (.) or string at ... Use of uninitialized value in concatenation (.) or string at ... c,, 'abcde' =~ m[(.)(.)(.)] and print "$1,$2,$3";; a,b,c` [download] all these regexes are untested. You might consider revising that policy. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l] [select]

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Re^5: seeking improvement in my smiple program using regular expression
by BrowserUk (Patriarch) on Aug 06, 2007 at 06:06 UTC

Repeated captures do not work. Only the last repetition actually captures anything. Contrast:

my @captures = 'abcde' =~ m[(.){3}];
print "@captures";;
c
[download]

with

my @captures = 'abcde' =~ m[(.)(.)(.)];;
print "@captures";;
a b c
[download]

and

'abcde' =~ m[(.){3}] and print "$1,$2,$3";;
Use of uninitialized value in concatenation (.) or string at ...
Use of uninitialized value in concatenation (.) or string at ...
c,,

'abcde' =~ m[(.)(.)(.)] and print "$1,$2,$3";;
a,b,c
[download]

all these regexes are untested.

You might consider revising that policy.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

[reply]
[d/l]
[select]