How to match anything up until this sequence of characters in a regular expression

Question

Take this regular expression      abc    This will match any single character at the beginning of a string  except a  b  or c   If you add a   after it         abc        the regular expression will continue to add each subsequent character to the result  until it meets either an a  or b  or c   For example  with the source string  qwerty qwerty whatever abc hello   the expression will match up to  qwerty qwerty wh     But what if I wanted the matching string to be  qwerty qwerty whatever        In other words  how can I match everything up to  but not including  the exact sequence  abc

User · Answer

I believe you need subexpressions  If I remember right you can use  the normal    brackets for subexpressions   This part is From grep manual    Back References and Subexpressions        The back-reference  n  where n is a single digit  matches the substring        previously matched  by  the  nth  parenthesized  subexpression  of  the        regular expression    Do something like     abc   should do the trick

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If you re looking to capture everything up to  abc           abc    Explanation       capture the expression inside the parentheses for access using  1   2  etc     match start of line     match anything    non-greedily  match the minimum number of characters required  -  1    1  The reason why this is needed is that otherwise  in the following string   whatever whatever something abc something abc   by default  regexes are greedy  meaning it will match as much as possible  Therefore     abc  would match  whatever whatever something abc something    Adding the non-greedy quantifier   makes the regex only match  whatever whatever something

User · Answer

As  Jared Ng and  Issun pointed out  the key to solve this kind of RegEx like  matching everything up to a certain word or substring  or  matching everything after a certain word or substring  is called  lookaround  zero-length assertions  Read more about them here   In your particular case  it can be solved by a positive look ahead        abc    A picture is worth a thousand words  See the detail explanation in the screenshot

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I ended in this stackoverflow question after looking for help to solve my problem but found no solution to it     So I had to improvise    after some time I managed to reach the regex I needed     As you can see  I needed up to one folder ahead of  grp-bps  folder  without including last dash  And it was required to have at least one folder after  grp-bps  folder   Edit  Text version for copy-paste  change  grp-bps  for your text        grp-bps

User · Answer

try this      efg   Query     select REGEXP REPLACE   abcdefghijklmn      efg       FROM dual    output      hijklmn

User · Answer

The   marks the end of a string  so something like this should work     abc     where you re looking for anything NOT ENDING in any iteration of abc  but it would have to be at the end  Also if you re using a scripting language with regex  like php or js   they have a search function that stops when it first encounters a pattern  and you can specify start from the left or start from the right  or with php  you can do an implode to mirror the string

User · Answer

What you need is look around assertion like        abc    See  Lookahead and Lookbehind Zero-Length Assertions  Be aware that  abc  isn t the same as abc  Inside brackets it s not a string - each character is just one of the possibilities  Outside the brackets it becomes the string

User · Answer

On python         abc  works for the single line case           abc  does not work  since python doesn t recognize     as valid regex  To make multiline matching work  you ll need to use the re DOTALL option  for example   re findall        abc    data  re DOTALL

User · Answer

This will make sense about regex    The exact word can be get from the following regex command                 g   Here  we can get the exact word globally which is belonging inside the double quotes  For Example  If our search text is    This is the example for  double quoted  words  then we will get  double quoted  from that sentence

User · Answer

For regex in Java  and I believe also in most regex engines  if you want to include the last part this will work       abc    For example  in this line   I have this very nice senabctence   select all characters until  abc  and also include abc  using our regex  the result will be  I have this very nice senabc  Test this out  https   regex101 com r mX51ru 1

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You didn t  specify which flavor  of regex  you re using  but  this will work in any of the most popular ones that can be considered  complete           abc     How it works  The       part is  the  un-greedy  version of       one  or more  of anything   When we use     the engine will basically match everything  Then  if there is  something else in the regex it will  go back in steps trying to  match the  following part  This  is the  greedy behavior  meaning as much as possible to satisfy   When using       instead of  matching all at  once and going  back for other conditions  if any   the engine  will match the next characters by step until the  subsequent part of the regex is  matched  again if any   This  is  the un-greedy   meaning  match  the fewest  possible  to satisfy      X      abcXabcXabcX                  abcXabcXabcX                                                            X     abcXabcXabcX                  abcXabcXabcX                                              Following  that   we  have       contents     a   zero  width assertion   a  look around   This  grouped  construction matches  its contents  but does not count  as characters matched  zero width   It only returns if it is a match or not  assertion    Thus  in other terms the regex        abc   means      Match any  characters as  few  as possible  until a   abc  is  found    without counting the  abc

[regex] How to match "anything up until this sequence of characters" in a regular expression?

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