How do I make a perl regular expresion fail in the code block?











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1
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I've got a screw I'm trying to nail in with perl and so far this is what I've got so far.



perl -ne '/(.+).(.+)((.+))(.+)(?{print "match" if  ( $1 > 9 || ( $1 == 9 && $2 > 1 ) || ($1 == 9 && $2 == 1 && $3 > 7 ) || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22 ) })/' versions


versions:



9.1(7)23
9.1(7)22
8.1(7)22
7.2(33)24
55


it will print "match" if the version in the file is > than 9.1(7)23, which is good.



But I want the regexp to succeed, not just print "match". How do I translate the stuff inside the code block to an actual response. I've tried quite a few iterations with *ACCEPT|*FAIL but nothing has worked so far.










share|improve this question






















  • Maybe using (??{}) instead of (?{}): /(.+).(.+)((.+))(.+)(??{ your_condition ? "" : "(*FAIL)"})/ ? I mean, this is OK if you are writing some quick one-liner for a one time job; but if this is supposed to be maintainable, production code, then don't try to do this with just a regex of course ;)
    – Dada
    2 days ago












  • (peharps "(*ACCEPT)" instead of "". Both work, and I have no opinion on which is "better". ACCEPT is more explicit I guess; but since you are writing something not readable at all, does it really matter?)
    – Dada
    2 days ago










  • @dada yeah, it's gotta be a one liner. I'm injecting into some version matching thing into some script to help a network guy out using their own tools. But that totally worked, thanks a lot you want to make it a legit answer to get credit?
    – Peter Turner
    2 days ago

















up vote
1
down vote

favorite












I've got a screw I'm trying to nail in with perl and so far this is what I've got so far.



perl -ne '/(.+).(.+)((.+))(.+)(?{print "match" if  ( $1 > 9 || ( $1 == 9 && $2 > 1 ) || ($1 == 9 && $2 == 1 && $3 > 7 ) || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22 ) })/' versions


versions:



9.1(7)23
9.1(7)22
8.1(7)22
7.2(33)24
55


it will print "match" if the version in the file is > than 9.1(7)23, which is good.



But I want the regexp to succeed, not just print "match". How do I translate the stuff inside the code block to an actual response. I've tried quite a few iterations with *ACCEPT|*FAIL but nothing has worked so far.










share|improve this question






















  • Maybe using (??{}) instead of (?{}): /(.+).(.+)((.+))(.+)(??{ your_condition ? "" : "(*FAIL)"})/ ? I mean, this is OK if you are writing some quick one-liner for a one time job; but if this is supposed to be maintainable, production code, then don't try to do this with just a regex of course ;)
    – Dada
    2 days ago












  • (peharps "(*ACCEPT)" instead of "". Both work, and I have no opinion on which is "better". ACCEPT is more explicit I guess; but since you are writing something not readable at all, does it really matter?)
    – Dada
    2 days ago










  • @dada yeah, it's gotta be a one liner. I'm injecting into some version matching thing into some script to help a network guy out using their own tools. But that totally worked, thanks a lot you want to make it a legit answer to get credit?
    – Peter Turner
    2 days ago















up vote
1
down vote

favorite









up vote
1
down vote

favorite











I've got a screw I'm trying to nail in with perl and so far this is what I've got so far.



perl -ne '/(.+).(.+)((.+))(.+)(?{print "match" if  ( $1 > 9 || ( $1 == 9 && $2 > 1 ) || ($1 == 9 && $2 == 1 && $3 > 7 ) || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22 ) })/' versions


versions:



9.1(7)23
9.1(7)22
8.1(7)22
7.2(33)24
55


it will print "match" if the version in the file is > than 9.1(7)23, which is good.



But I want the regexp to succeed, not just print "match". How do I translate the stuff inside the code block to an actual response. I've tried quite a few iterations with *ACCEPT|*FAIL but nothing has worked so far.










share|improve this question













I've got a screw I'm trying to nail in with perl and so far this is what I've got so far.



perl -ne '/(.+).(.+)((.+))(.+)(?{print "match" if  ( $1 > 9 || ( $1 == 9 && $2 > 1 ) || ($1 == 9 && $2 == 1 && $3 > 7 ) || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22 ) })/' versions


versions:



9.1(7)23
9.1(7)22
8.1(7)22
7.2(33)24
55


it will print "match" if the version in the file is > than 9.1(7)23, which is good.



But I want the regexp to succeed, not just print "match". How do I translate the stuff inside the code block to an actual response. I've tried quite a few iterations with *ACCEPT|*FAIL but nothing has worked so far.







perl pcre






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 2 days ago









Peter Turner

4,891753101




4,891753101












  • Maybe using (??{}) instead of (?{}): /(.+).(.+)((.+))(.+)(??{ your_condition ? "" : "(*FAIL)"})/ ? I mean, this is OK if you are writing some quick one-liner for a one time job; but if this is supposed to be maintainable, production code, then don't try to do this with just a regex of course ;)
    – Dada
    2 days ago












  • (peharps "(*ACCEPT)" instead of "". Both work, and I have no opinion on which is "better". ACCEPT is more explicit I guess; but since you are writing something not readable at all, does it really matter?)
    – Dada
    2 days ago










  • @dada yeah, it's gotta be a one liner. I'm injecting into some version matching thing into some script to help a network guy out using their own tools. But that totally worked, thanks a lot you want to make it a legit answer to get credit?
    – Peter Turner
    2 days ago




















  • Maybe using (??{}) instead of (?{}): /(.+).(.+)((.+))(.+)(??{ your_condition ? "" : "(*FAIL)"})/ ? I mean, this is OK if you are writing some quick one-liner for a one time job; but if this is supposed to be maintainable, production code, then don't try to do this with just a regex of course ;)
    – Dada
    2 days ago












  • (peharps "(*ACCEPT)" instead of "". Both work, and I have no opinion on which is "better". ACCEPT is more explicit I guess; but since you are writing something not readable at all, does it really matter?)
    – Dada
    2 days ago










  • @dada yeah, it's gotta be a one liner. I'm injecting into some version matching thing into some script to help a network guy out using their own tools. But that totally worked, thanks a lot you want to make it a legit answer to get credit?
    – Peter Turner
    2 days ago


















Maybe using (??{}) instead of (?{}): /(.+).(.+)((.+))(.+)(??{ your_condition ? "" : "(*FAIL)"})/ ? I mean, this is OK if you are writing some quick one-liner for a one time job; but if this is supposed to be maintainable, production code, then don't try to do this with just a regex of course ;)
– Dada
2 days ago






Maybe using (??{}) instead of (?{}): /(.+).(.+)((.+))(.+)(??{ your_condition ? "" : "(*FAIL)"})/ ? I mean, this is OK if you are writing some quick one-liner for a one time job; but if this is supposed to be maintainable, production code, then don't try to do this with just a regex of course ;)
– Dada
2 days ago














(peharps "(*ACCEPT)" instead of "". Both work, and I have no opinion on which is "better". ACCEPT is more explicit I guess; but since you are writing something not readable at all, does it really matter?)
– Dada
2 days ago




(peharps "(*ACCEPT)" instead of "". Both work, and I have no opinion on which is "better". ACCEPT is more explicit I guess; but since you are writing something not readable at all, does it really matter?)
– Dada
2 days ago












@dada yeah, it's gotta be a one liner. I'm injecting into some version matching thing into some script to help a network guy out using their own tools. But that totally worked, thanks a lot you want to make it a legit answer to get credit?
– Peter Turner
2 days ago






@dada yeah, it's gotta be a one liner. I'm injecting into some version matching thing into some script to help a network guy out using their own tools. But that totally worked, thanks a lot you want to make it a legit answer to get credit?
– Peter Turner
2 days ago














1 Answer
1






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oldest

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up vote
4
down vote













First of all, the regex does succeed. But it does so whether the condition is true or not. I think you're actually asking for it to fail when the condition is false. For that, you want



(?(?{ condition })(*ACCEPT)|(*FAIL))


or just



(?(?{ !condition })(*FAIL))


Fixed:



perl -nle'
print "$_: match"
if /
^(.+).(.+)((.+))(.+)z
(?(?{
!( $1 > 9
|| $1 == 9 && $2 > 1
|| $1 == 9 && $2 == 1 && $3 > 7
|| $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
)
})(*FAIL))
/x;
' versions


A far better approach is to do the check outside of the pattern.



perl -nle'
print "$_: match"
if /^(.+).(.+)((.+))(.+)z/
&& (
$1 > 9
|| $1 == 9 && $2 > 1
|| $1 == 9 && $2 == 1 && $3 > 7
|| $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
);
' versions





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    1 Answer
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    active

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    active

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    up vote
    4
    down vote













    First of all, the regex does succeed. But it does so whether the condition is true or not. I think you're actually asking for it to fail when the condition is false. For that, you want



    (?(?{ condition })(*ACCEPT)|(*FAIL))


    or just



    (?(?{ !condition })(*FAIL))


    Fixed:



    perl -nle'
    print "$_: match"
    if /
    ^(.+).(.+)((.+))(.+)z
    (?(?{
    !( $1 > 9
    || $1 == 9 && $2 > 1
    || $1 == 9 && $2 == 1 && $3 > 7
    || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
    )
    })(*FAIL))
    /x;
    ' versions


    A far better approach is to do the check outside of the pattern.



    perl -nle'
    print "$_: match"
    if /^(.+).(.+)((.+))(.+)z/
    && (
    $1 > 9
    || $1 == 9 && $2 > 1
    || $1 == 9 && $2 == 1 && $3 > 7
    || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
    );
    ' versions





    share|improve this answer



























      up vote
      4
      down vote













      First of all, the regex does succeed. But it does so whether the condition is true or not. I think you're actually asking for it to fail when the condition is false. For that, you want



      (?(?{ condition })(*ACCEPT)|(*FAIL))


      or just



      (?(?{ !condition })(*FAIL))


      Fixed:



      perl -nle'
      print "$_: match"
      if /
      ^(.+).(.+)((.+))(.+)z
      (?(?{
      !( $1 > 9
      || $1 == 9 && $2 > 1
      || $1 == 9 && $2 == 1 && $3 > 7
      || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
      )
      })(*FAIL))
      /x;
      ' versions


      A far better approach is to do the check outside of the pattern.



      perl -nle'
      print "$_: match"
      if /^(.+).(.+)((.+))(.+)z/
      && (
      $1 > 9
      || $1 == 9 && $2 > 1
      || $1 == 9 && $2 == 1 && $3 > 7
      || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
      );
      ' versions





      share|improve this answer

























        up vote
        4
        down vote










        up vote
        4
        down vote









        First of all, the regex does succeed. But it does so whether the condition is true or not. I think you're actually asking for it to fail when the condition is false. For that, you want



        (?(?{ condition })(*ACCEPT)|(*FAIL))


        or just



        (?(?{ !condition })(*FAIL))


        Fixed:



        perl -nle'
        print "$_: match"
        if /
        ^(.+).(.+)((.+))(.+)z
        (?(?{
        !( $1 > 9
        || $1 == 9 && $2 > 1
        || $1 == 9 && $2 == 1 && $3 > 7
        || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
        )
        })(*FAIL))
        /x;
        ' versions


        A far better approach is to do the check outside of the pattern.



        perl -nle'
        print "$_: match"
        if /^(.+).(.+)((.+))(.+)z/
        && (
        $1 > 9
        || $1 == 9 && $2 > 1
        || $1 == 9 && $2 == 1 && $3 > 7
        || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
        );
        ' versions





        share|improve this answer














        First of all, the regex does succeed. But it does so whether the condition is true or not. I think you're actually asking for it to fail when the condition is false. For that, you want



        (?(?{ condition })(*ACCEPT)|(*FAIL))


        or just



        (?(?{ !condition })(*FAIL))


        Fixed:



        perl -nle'
        print "$_: match"
        if /
        ^(.+).(.+)((.+))(.+)z
        (?(?{
        !( $1 > 9
        || $1 == 9 && $2 > 1
        || $1 == 9 && $2 == 1 && $3 > 7
        || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
        )
        })(*FAIL))
        /x;
        ' versions


        A far better approach is to do the check outside of the pattern.



        perl -nle'
        print "$_: match"
        if /^(.+).(.+)((.+))(.+)z/
        && (
        $1 > 9
        || $1 == 9 && $2 > 1
        || $1 == 9 && $2 == 1 && $3 > 7
        || $1 == 9 && $2 == 1 && $3 == 7 && $4 > 22
        );
        ' versions






        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited 2 days ago

























        answered 2 days ago









        ikegami

        259k11172392




        259k11172392






























             

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