Re^3: Problem in pattern matching with alternation

I appreciate that you are trying, but you are still not making any sense. You are not using "code" tags enough in your posts, you are not giving us anything we can try to run ourselves to demonstrate your problem, and you keep confusing "slash" with "\".

I'll propose the following, which is based on code and data in the original post at the top of this thread. Please try this out, tell us whether it works for you, and if it doesn't (and you are still stumped about how to make it work), tell us exactly how it should work.

#!/usr/bin/perl

use strict;
use warnings;

while (<DATA>) {
    print "$1\n" if ( m{^\*\s+(?:/\w+)+\s+(.+?)\s+} );
}

__DATA__
* /vobs/bt_rel /usr/add-on/puccase_vob01/ccvob01/bt_rel.vbs public (re
+plicated)
* /scm /usr/add-on/puccase_vob01/ccvob01/scm.vbs public (replicated)
* /v_dialermidtier /usr/addon/puccase_vob01/ccvob01/v_dialermidtier.vb
+s public (replicated)
* /v_dialer /usr/add-on/puccase_vob01/ccvob01/v_dialer.vbs public (rep
+licated)
* /vobs/UMTools /user/addon/puccase_vob01/ccvob01/UMtools.vbs replicat
+ed)
[download]

The difference between that and the OP code is:

it loops over each line of input, instead of reporting only a single output from all lines of input
it escapes the initial "*" character in the regex, to avoid a syntax error
it puts curlies around the regex, to avoid \/ (toothpick syndrome)
it allows the first string following "*" to contain any number (1 or more) of adjacent "/word" patterns (but does not capture this string)

If you are just trying to get the third space-delimited token from each line of input, you could do this for each line, instead of the regex match:

     print +(split /\s+/)[2];  # print third "word" of line
[download]

(updated to include "+" outside the parens -- thanks, naikonta!)

If the data shown above is not correct, show us the actual data (inside <code> tags, please). If the output is not what you want, show us exactly what you want (based on the correct input data, again using <code> tags).

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Re^4: Problem in pattern matching with alternation by naikonta (Curate) on Aug 13, 2007 at 08:52 UTC
`print (split /\s+/)[2]; # print third "word" of line` Ooops, you forget the + :-) It gives me, `syntax error at __FILE__ line __LINE__, near ")[" Execution of -e aborted due to compilation errors.` [download] Open source softwares? Share and enjoy. Make profit from them if you can. Yet, share and enjoy!	[reply] [d/l] [select]
Re^4: Problem in pattern matching with alternation by perladdict (Chaplain) on Aug 12, 2007 at 17:35 UTC
Hi graff, Here i am explaining in detail what actually i am trying to extract. I am working on a task to get the vob storage path from the list of vobtags.below is the command i am running on command prompt bash-3.00$cleartool lsvob -s #which will give all vobtag list as below. `/vobs/cs_test_scripts /vobs/openwall_pam_userpass_rel /vobs/cs_cim /vobs/PIP_PVOB /vobs/pvob_ic /v_dialer3rdparty /v_dialerclient /v_dialer_rel /scm` [download] #!/usr/bin/perl -w $arg=$ARGV[0]; $cmd="cleartool lsvob $arg" $arr=`$cmd`; print "$arr\n"; [download] after running this script with argument as vobtag list that i got from running "cleartool lsvob -s" command like as bash-3.0$cleartool lsvob /vobs/cs_test_scripts from command prompt will give the result as below `* /vobs/cs_test_scripts /usr/add-on/puccase_vob01/ccvob01/cs_test_scri +pts.vbs public (replicated) * /scm /usr/add-on/puccase_vob01/ccvob01/scm.test.vbs` [download] the output contains three parts /vobs/cs_test_script,/scm are as vobtags /usr/add-on/puccase_vob01/ccvob01/cs_test_scripts.vbs is vobstorage directory path and last part is type as "public (replicated)". from this i want to extract vobstorage path of each vobtag that i am supling vobtag(/vobs/cs_test_script)as argument to the below script,in that i am matching the output for the tags with 2 slashes in it ex:/vobs/cs_test_script and vobtag with one slash in it ex:/scm with regular expression that has to match the output for both type of vobtags(/vobs/cs_test_script,/scm)by using alternation operator in patternmatching as below script #!/usr/bin/perl $arg=$ARGV[0]; $cmd1="cleartool lsvob $arg"; $arr=`$cmd1`; print "$arr\n"; $storage1=$1 if($arr=~/^\s+\/\w+\/\w+\s+(.+)\s+\w+/); print "$storage1\n"; $storage2=$1 if($arr=~/^\s+\/\w+\s+(.+)\s+\w+/); print "$storage2\n"; $storage3=$1 if($arr=~/^\s+\/\w+\/\w+\s+(.+)\s+\w+\|^\s+\/\w+\s+(.+)\ +s+\w+/); print "$storage3\n"; [download] I am running the script with both type of vobtags as /vobs/cs_test_scripts and /scm as arguments so its printing the match for both $storage1 and $storage2 as below bash-3.00$ perl scriptname.pl /vobs/cs_test_script bash-3.00$ perl scriptname.pl /scm `* /vobs/cs_test_scripts /usr/add-on/puccase_vob01/ccvob01/cs_test_scri +pts.vbs public (replicated) #match storage1 /usr/add-on/puccase_vob01/ccvob01/cs_test_scripts.vbs * /scm /usr/add-on/puccase_vob01/ccvob01/scm.vbs publi +c (replicated) #storage2 /usr/add-on/puccase_vob01/ccvob01/scm.vbs` [download] In $storage3 variable i am combining the pattern match of storage1 and storage2 by alternation operator,it should work for both type of vobtag arguments,i am not getting where i am doing wrong... Monks sorry for repeated posting of same qustion again and again...the problems seems to simple for u people ....	[reply] [d/l] [select]
Re^5: Problem in pattern matching with alternation by graff (Chancellor) on Aug 12, 2007 at 20:13 UTC
Here i am explaining in detail what actually i am trying to extract. And you seem to be completely ignoring (or not understanding) the code sample and suggestions that I posted. If you don't understand something I've said or something in my code, it's okay to quote me in a reply and say that you don't understand. i am matching the output for the tags with 2 slashes in it ex:/vobs/cs_test_script and vobtag with one slash in it ex:/scm with regular expression that has to match the output for both type of vobtags(/vobs/cs_test_script,/scm)by using alternation operator in pattern matching as below script Checking your code, I have learned something. I expected that if a regex that starts like this: `/^\s+/` it would be a syntax error, and the script would not run at all. But having tried it, I see that it does run (it's not an error), and it even seems to work: `$_=" foo"; m{^\s+foo}` returns true. Still, I prefer using a backslash when I want to match a literal "" character. Note that `m{\s+foo}` is a syntax error. (And make sure you understand the distinction: slash is "/", backslash is "\", and the two have very different meanings and uses in perl.) i am combining the pattern match of storage1 and storage2 by alternation operator* You don't need to use an alternation (`\|`) in the regex. The code that I suggested above uses a quantifier, so that one, two, three or more slashes in the path string can be treated by the single expression -- shown here with commentary: `m{^ # at the start of the string \* # match a literal asterisk character \s+ # then one or more whitespace characters (?: # begin a non-capturing group expression / # match a literal slash character \w+ # then one or more alphanumeric_word characters )+ # close the group, match 1 or more instances of that expr +ession \s+ # then one or more whitespace characters (\S+) # capture a group of non-whitespace characters }x # end of regex (x modifier lets comments and spacing be i +gnored)` [download] The last couple things that you are not paying attention to are: whether you need to be processing your data line by line, rather than slurping all the lines into a single "$arr" variable, and whether you would be better off using "split" instead of regex matches.	[reply] [d/l] [select]
Re^5: Problem in pattern matching with alternation by FunkyMonk (Bishop) on Aug 12, 2007 at 17:57 UTC
That's better (I think). Your input data look like this: `* /vobs/cs_test_scripts /usr/add-on/puccase_vob01/ccvob01/cs_test_scri +pts.vbs public (replicated) * /scm /usr/add-on/puccase_vob01/ccvob01/scm.test.vbs` [download] And your output should be: `/usr/add-on/puccase_vob01/ccvob01/cs_test_scripts.vbs /usr/add-on/puccase_vob01/ccvob01/scm.test.vbs` [download] I wouldn't do this with regular expressions, I'd use split: `my @data = ( "* /vobs/cs_test_scripts /usr/add-on/puccase_vob01/ccvob01/cs_test_s +cripts.vbs public (replicated)", "* /scm /usr/add-on/puccase_vob01/ccvob01/scm.test.vbs" ); for ( @data ) { my $path = (split)[2]; print "$path\n"; }` [download] Outputs: `/usr/add-on/puccase_vob01/ccvob01/cs_test_scripts.vbs /usr/add-on/puccase_vob01/ccvob01/scm.test.vbs` [download] Is that what you're after?	[reply] [d/l] [select]