Regular Expressions Is there an AND operator

Question

Obviously  you can use the    pipe   to represent OR  but is there a way to represent AND as well   Specifically  I d like to match paragraphs of text that contain ALL of a certain phrase  but in no particular order

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You could pipe your output to another regex   Using grep  you could do this   grep A   grep B

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yes    no     no    yes   Will match sentence having both yes and no at the same time  regardless the order in which they appear  Do i like cookies    Yes    i do  But milk -   no    definitely no    No    you may not have my phone    Yes    you may go f yourself  Will both match  ignoring case

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If you use Perl regular expressions  you can use positive lookahead   For example      1-9  0-9  2   0-9   05  b   would be numbers greater than 100 and divisible by 5

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Is it not possible in your case to do the AND on several matching results  in pseudocode  regexp match pattern1  data   amp  amp  regexp match pattern2  data   amp  amp

User · Answer

The order is always implied in the structure of the regular expression  To accomplish what you want  you ll have to match the input string multiple times against different expressions   What you want to do is not possible with a single regexp

User · Answer

The order is always implied in the structure of the regular expression  To accomplish what you want  you ll have to match the input string multiple times against different expressions   What you want to do is not possible with a single regexp

User · Answer

If you use Perl regular expressions  you can use positive lookahead   For example      1-9  0-9  2   0-9   05  b   would be numbers greater than 100 and divisible by 5

User · Answer

Is it not possible in your case to do the AND on several matching results  in pseudocode  regexp match pattern1  data   amp  amp  regexp match pattern2  data   amp  amp

User · Answer

If you use Perl regular expressions  you can use positive lookahead   For example      1-9  0-9  2   0-9   05  b   would be numbers greater than 100 and divisible by 5

User · Answer

yes    no     no    yes   Will match sentence having both yes and no at the same time  regardless the order in which they appear  Do i like cookies    Yes    i do  But milk -   no    definitely no    No    you may not have my phone    Yes    you may go f yourself  Will both match  ignoring case

User · Answer

You need to use lookahead as some of the other responders have said  but the lookahead has to account for other characters between its target word and the current match position   For example        word1      word2      word3    The    in the first lookahead lets it match however many characters it needs to before it gets to  word1    Then the match position is reset and the second lookahead seeks out  word2    Reset again  and the final part matches  word3   since it s the last word you re checking for  it isn t necessary that it be in a lookahead  but it doesn t hurt   In order to match a whole paragraph  you need to anchor the regex at both ends and add a final    to consume the remaining characters   Using Perl-style notation  that would be          word1      word2      word3     m   The  m  modifier is for multline mode  it lets the   and   match at paragraph boundaries   line boundaries  in regex-speak    It s essential in this case that you not use the  s  modifier  which lets the dot metacharacter match newlines as well as all other characters     Finally  you want to make sure you re matching whole words and not just fragments of longer words  so you need to add word boundaries           bword1 b       bword2 b       bword3 b     m

User · Answer

You can do that with a regular expression but probably you ll want to some else  For example  use several regexp and combine them in a if clause    You can enumerate all possible permutations with a standard regexp  like this  matches a  b and c in any order     abc   bca   acb   bac   cab   cba    However  this makes a very long and probably inefficient regexp  if you have more than couple terms   If you are using some extended regexp version  like Perl s or Java s  they have better ways to do this  Other answers have suggested using positive lookahead operation

User · Answer

The order is always implied in the structure of the regular expression  To accomplish what you want  you ll have to match the input string multiple times against different expressions   What you want to do is not possible with a single regexp

User · Answer

Why not use awk  with awk regex AND  OR matters is so simple  awk   WORD1   amp  amp   WORD2   amp  amp   WORD3   myfile

User · Answer

Is it not possible in your case to do the AND on several matching results  in pseudocode  regexp match pattern1  data   amp  amp  regexp match pattern2  data   amp  amp

User · Answer

Use a non-consuming regular expression   The typical  i e  Perl Java  notation is      expr   This means  match expr but after that continue matching at the original match-point      You can do as many of these as you want  and this will be an  and    Example      match this expression    match this too    oh  and this   You can even add capture groups inside the non-consuming expressions if you need to save some of the data therein

User · Answer

Look at this example   We have 2 regexps A and B and we want to match both of them  so in pseudo-code it looks like this   pattern     A AND B     It can be written without using the AND operator like this   pattern     NOT  NOT A OR NOT B      in PCRE         A  B      regexp match pattern data

User · Answer

You can do that with a regular expression but probably you ll want to some else  For example  use several regexp and combine them in a if clause    You can enumerate all possible permutations with a standard regexp  like this  matches a  b and c in any order     abc   bca   acb   bac   cab   cba    However  this makes a very long and probably inefficient regexp  if you have more than couple terms   If you are using some extended regexp version  like Perl s or Java s  they have better ways to do this  Other answers have suggested using positive lookahead operation

User · Answer

You need to use lookahead as some of the other responders have said  but the lookahead has to account for other characters between its target word and the current match position   For example        word1      word2      word3    The    in the first lookahead lets it match however many characters it needs to before it gets to  word1    Then the match position is reset and the second lookahead seeks out  word2    Reset again  and the final part matches  word3   since it s the last word you re checking for  it isn t necessary that it be in a lookahead  but it doesn t hurt   In order to match a whole paragraph  you need to anchor the regex at both ends and add a final    to consume the remaining characters   Using Perl-style notation  that would be          word1      word2      word3     m   The  m  modifier is for multline mode  it lets the   and   match at paragraph boundaries   line boundaries  in regex-speak    It s essential in this case that you not use the  s  modifier  which lets the dot metacharacter match newlines as well as all other characters     Finally  you want to make sure you re matching whole words and not just fragments of longer words  so you need to add word boundaries           bword1 b       bword2 b       bword3 b     m

User · Answer

Is it not possible in your case to do the AND on several matching results  in pseudocode  regexp match pattern1  data   amp  amp  regexp match pattern2  data   amp  amp

User · Answer

If you use Perl regular expressions  you can use positive lookahead   For example      1-9  0-9  2   0-9   05  b   would be numbers greater than 100 and divisible by 5

User · Answer

The AND operator is implicit in the RegExp syntax  The OR operator has instead to be specified with a pipe  The following RegExp   var re    ab     means the letter a AND the letter b  It also works with groups   var re     co  de      it means the group co AND the group de  Replacing the  implicit  AND with an OR would require the following lines   var re    a b   var re     co   de

User · Answer

Why not use awk  with awk regex AND  OR matters is so simple  awk   WORD1   amp  amp   WORD2   amp  amp   WORD3   myfile

User · Answer

Use AND outside the regular expression  In PHP lookahead operator did not not seem to work for me  instead I used this  if  preg match      3       pass1   amp  amp   preg match    s 1     pass1       return true  else     return false    The above regex will match if the password length is 3 characters or more and there are no spaces in the password

User · Answer

You can do that with a regular expression but probably you ll want to some else  For example  use several regexp and combine them in a if clause    You can enumerate all possible permutations with a standard regexp  like this  matches a  b and c in any order     abc   bca   acb   bac   cab   cba    However  this makes a very long and probably inefficient regexp  if you have more than couple terms   If you are using some extended regexp version  like Perl s or Java s  they have better ways to do this  Other answers have suggested using positive lookahead operation

User · Answer

Use a non-consuming regular expression   The typical  i e  Perl Java  notation is      expr   This means  match expr but after that continue matching at the original match-point      You can do as many of these as you want  and this will be an  and    Example      match this expression    match this too    oh  and this   You can even add capture groups inside the non-consuming expressions if you need to save some of the data therein

User · Answer

Use a non-consuming regular expression   The typical  i e  Perl Java  notation is      expr   This means  match expr but after that continue matching at the original match-point      You can do as many of these as you want  and this will be an  and    Example      match this expression    match this too    oh  and this   You can even add capture groups inside the non-consuming expressions if you need to save some of the data therein

User · Answer

Look at this example   We have 2 regexps A and B and we want to match both of them  so in pseudo-code it looks like this   pattern     A AND B     It can be written without using the AND operator like this   pattern     NOT  NOT A OR NOT B      in PCRE         A  B      regexp match pattern data

User · Answer

You need to use lookahead as some of the other responders have said  but the lookahead has to account for other characters between its target word and the current match position   For example        word1      word2      word3    The    in the first lookahead lets it match however many characters it needs to before it gets to  word1    Then the match position is reset and the second lookahead seeks out  word2    Reset again  and the final part matches  word3   since it s the last word you re checking for  it isn t necessary that it be in a lookahead  but it doesn t hurt   In order to match a whole paragraph  you need to anchor the regex at both ends and add a final    to consume the remaining characters   Using Perl-style notation  that would be          word1      word2      word3     m   The  m  modifier is for multline mode  it lets the   and   match at paragraph boundaries   line boundaries  in regex-speak    It s essential in this case that you not use the  s  modifier  which lets the dot metacharacter match newlines as well as all other characters     Finally  you want to make sure you re matching whole words and not just fragments of longer words  so you need to add word boundaries           bword1 b       bword2 b       bword3 b     m

User · Answer

In addition to the accepted answer   I will provide you with some practical examples that will get things more clear to some of You  For example lets say we have those three lines of text    12 Oct 2015 00 37 29  0200     only this   will get selected  12 Oct 2015 00 37 x9  0200   12 Oct 2015 00 37 29  020x    See demo here DEMO  What we want to do here is to select the   sign but only if it s after two numbers with a space and if it s before four numbers  Those are the only constraints  We would use this regular expression to achieve it        lt   d 2         d 4   g    Note if you separate the expression it will give you different results    Or perhaps you want to select some text between tags    but not the tags  Then you could use        lt   lt p gt         lt   p gt   g    for this text     lt p gt Hello   lt  p gt   lt p gt I wont select tags  Only text with in lt  p gt     See demo here DEMO

User · Answer

The order is always implied in the structure of the regular expression  To accomplish what you want  you ll have to match the input string multiple times against different expressions   What you want to do is not possible with a single regexp

User · Answer

In addition to the accepted answer   I will provide you with some practical examples that will get things more clear to some of You  For example lets say we have those three lines of text    12 Oct 2015 00 37 29  0200     only this   will get selected  12 Oct 2015 00 37 x9  0200   12 Oct 2015 00 37 29  020x    See demo here DEMO  What we want to do here is to select the   sign but only if it s after two numbers with a space and if it s before four numbers  Those are the only constraints  We would use this regular expression to achieve it        lt   d 2         d 4   g    Note if you separate the expression it will give you different results    Or perhaps you want to select some text between tags    but not the tags  Then you could use        lt   lt p gt         lt   p gt   g    for this text     lt p gt Hello   lt  p gt   lt p gt I wont select tags  Only text with in lt  p gt     See demo here DEMO

User · Answer

You need to use lookahead as some of the other responders have said  but the lookahead has to account for other characters between its target word and the current match position   For example        word1      word2      word3    The    in the first lookahead lets it match however many characters it needs to before it gets to  word1    Then the match position is reset and the second lookahead seeks out  word2    Reset again  and the final part matches  word3   since it s the last word you re checking for  it isn t necessary that it be in a lookahead  but it doesn t hurt   In order to match a whole paragraph  you need to anchor the regex at both ends and add a final    to consume the remaining characters   Using Perl-style notation  that would be          word1      word2      word3     m   The  m  modifier is for multline mode  it lets the   and   match at paragraph boundaries   line boundaries  in regex-speak    It s essential in this case that you not use the  s  modifier  which lets the dot metacharacter match newlines as well as all other characters     Finally  you want to make sure you re matching whole words and not just fragments of longer words  so you need to add word boundaries           bword1 b       bword2 b       bword3 b     m

User · Answer

Use AND outside the regular expression  In PHP lookahead operator did not not seem to work for me  instead I used this  if  preg match      3       pass1   amp  amp   preg match    s 1     pass1       return true  else     return false    The above regex will match if the password length is 3 characters or more and there are no spaces in the password

User · Answer

You could pipe your output to another regex   Using grep  you could do this   grep A   grep B

User · Answer

The AND operator is implicit in the RegExp syntax  The OR operator has instead to be specified with a pipe  The following RegExp   var re    ab     means the letter a AND the letter b  It also works with groups   var re     co  de      it means the group co AND the group de  Replacing the  implicit  AND with an OR would require the following lines   var re    a b   var re     co   de

User · Answer

Use a non-consuming regular expression   The typical  i e  Perl Java  notation is      expr   This means  match expr but after that continue matching at the original match-point      You can do as many of these as you want  and this will be an  and    Example      match this expression    match this too    oh  and this   You can even add capture groups inside the non-consuming expressions if you need to save some of the data therein

User · Answer

You can do that with a regular expression but probably you ll want to some else  For example  use several regexp and combine them in a if clause    You can enumerate all possible permutations with a standard regexp  like this  matches a  b and c in any order     abc   bca   acb   bac   cab   cba    However  this makes a very long and probably inefficient regexp  if you have more than couple terms   If you are using some extended regexp version  like Perl s or Java s  they have better ways to do this  Other answers have suggested using positive lookahead operation

[regex] Regular Expressions: Is there an AND operator?

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