preg_match to match number csv format and capture each number? - php

I want to use preg_match to parse '123,456,789,323' and only capture each number into arrray $m.
My php codes:
preg_match("/^(\d+)(?:,(\d+))*?$/",'123,456,789,323',$m));
print_r($m);
This is how I interpret my regexp:
^: Begin of line
1st (\d+): Capture 1st number
,(\d+): Match pattern 'a command then a number'.
(?:,(\d+))*?: Match zero or more [using *] of above pattern but don't
capture whole pattern [using ?:] instead only capture
the number [using (\d+)]. Lastly, match pattern
nongreedy [using last ?]
$: Match end of line.
But I get this output:
Array
(
[0] => 123,456,555,789,323
[1] => 123
[2] => 323
)
What I want is:
Array
(
[0] => 123,456,555,789,323
[1] => 123
[2] => 456
[3] => 789
[4] => 323
)
I thought (...)* is too greedy, so I use (...)*?. But it doesn't approve the output. What do I miss?
PS: I want to know how can regexp do this rather than use other way e.g. explode().

Related

Regex: Capturing multiple instances in one word group

I'm not good at Regex and I've been trying for hours now so I hope you can help me. I have this text:
✝his is *✝he* *in✝erne✝*
I need to capture (using PREG_OFFSET_CAPTURE) only the ✝ in a word surrounded with *, so I only need to capture the last three ✝ in this example. The output array should look something like this:
[0] => Array
(
[0] => ✝
[1] => 17
)
[1] => Array
(
[0] => ✝
[1] => 32
)
[2] => Array
(
[0] => ✝
[1] => 44
)
I've tried using (✝) but ofcourse this will select all instances including the words without asterisks. Then I've tried \*[^ ]*(✝)[^ ]*\* but this only gives me the last instance in one word. I've tried many other variations but all were wrong.
To clarify: The asterisk can be at all places in the string, but always at the beginning and end of a word. The opening asterisk always precedes a space except at the beginning of the string and the closing asterisk always ends with a space except at the end of the string. I must add that punctuation marks can be inside these asterisks. ✝ is exactly (and only) what I need to capture and can be at any position in a word.
You could make use of the \G anchor to get iterative matches between the *. The anchor matches either at the start of the string, or at the end of the previous match.
(?:\*|\G(?!^))[^&*]*(?>&(?!#)[^&*]*)*\K✝(?=[^*]*\*)
Explanation
(?: Non capture group
\* Match *
| Or
\G(?!^) Assert the end of the previous match, not at the start
) Close non capture group
[^&*]* Match 0+ times any char except & and *
(?> Atomic group
&(?!#) Match & only when not directly followed by #
[^&*]* Match 0+ times any char except & and *
)* Close atomic group and repeat 0+ times
\K Clear the match buffer (forget what is matched until now)
✝ Match literally
(?=[^*]*\*) Positive lookahead, assert a * at the right
Regex demo | Php demo
For example
$re = '/(?:\*|\G(?!^))[^&*]*(?>&(?!#)[^&*]*)*\K✝(?=[^*]*\*)/m';
$str = '✝his is *✝he* *in✝erne✝*';
preg_match_all($re, $str, $matches, PREG_OFFSET_CAPTURE);
print_r($matches[0]);
Output
Array
(
[0] => Array
(
[0] => ✝
[1] => 16
)
[1] => Array
(
[0] => ✝
[1] => 31
)
[2] => Array
(
[0] => ✝
[1] => 43
)
)
Note The the offset is 1 less than the expected as the string starts counting at 0. See PREG_OFFSET_CAPTURE
If you want to match more variations, you could use a non capturing group and list the ones that you would accept to match. If you don't want to cross newline boundaries you can exclude matching those in the negated character class.
(?:\*|\G(?!^))[^&*\r\n]*(?>&(?!#)[^&*\\rn]*)*\K&#(?:x271D|169);(?=[^*\r\n]*\*)
Regex demo

need some help on regex in preg_match_all()

so I need to extract the ticket number "Ticket#999999" from a string.. how do i do this using regex.
my current regex is working if I have more than one number in the Ticket#9999.. but if I only have Ticket#9 it's not working please help.
current regex.
preg_match_all('/(Ticket#[0-9])\w\d+/i',$data,$matches);
thank you.
In your pattern [0-9] matches 1 digit, \w matches another digit and \d+ matches 1+ digits, thus requiring 3 digits after #.
Use
preg_match_all('/Ticket#([0-9]+)/i',$data,$matches);
This will match:
Ticket# - a literal string Ticket#
([0-9]+) - Group 1 capturing 1 or more digits.
PHP demo:
$data = "Ticket#999999 ticket#9";
preg_match_all('/Ticket#([0-9]+)/i',$data,$matches, PREG_SET_ORDER);
print_r($matches);
Output:
Array
(
[0] => Array
(
[0] => Ticket#999999
[1] => 999999
)
[1] => Array
(
[0] => ticket#9
[1] => 9
)
)

split string by spaces and colon but not if inside quotes

having a string like this:
$str = "dateto:'2015-10-07 15:05' xxxx datefrom:'2015-10-09 15:05' yyyy asdf"
the desired result is:
[0] => Array (
[0] => dateto:'2015-10-07 15:05'
[1] => xxxx
[2] => datefrom:'2015-10-09 15:05'
[3] => yyyy
[4] => asdf
)
what I get with:
preg_match_all("/\'(?:[^()]|(?R))+\'|'[^']*'|[^(),\s]+/", $str, $m);
is:
[0] => Array (
[0] => dateto:'2015-10-07
[1] => 15:05'
[2] => xxxx
[3] => datefrom:'2015-10-09
[4] => 15:05'
[5] => yyyy
[6] => asdf
)
Also tried with preg_split("/[\s]+/", $str) but no clue how to escape if value is between quotes. Can anyone show me how and also please explain the regex. Thank you!
I would use PCRE verb (*SKIP)(*F),
preg_split("~'[^']*'(*SKIP)(*F)|\s+~", $str);
DEMO
Often, when you are looking to split a string, using preg_split isn't the best approach (that seems a little counter intuitive, but that's true most of the time). A more efficient way consists to find all items (with preg_match_all) using a pattern that describes all that is not the delimiter (white-spaces here):
$pattern = <<<'EOD'
~(?=\S)[^'"\s]*(?:'[^']*'[^'"\s]*|"[^"]*"[^'"\s]*)*~
EOD;
if (preg_match_all($pattern, $str, $m))
$result = $m[0];
pattern details:
~ # pattern delimiter
(?=\S) # the lookahead assertion only succeeds if there is a non-
# white-space character at the current position.
# (This lookahead is useful for two reasons:
# - it allows the regex engine to quickly find the start of
# the next item without to have to test each branch of the
# following alternation at each position in the strings
# until one succeeds.
# - it ensures that there's at least one non-white-space.
# Without it, the pattern may match an empty string.
# )
[^'"\s]* #"'# all that is not a quote or a white-space
(?: # eventual quoted parts
'[^']*' [^'"\s]* #"# single quotes
|
"[^"]*" [^'"\s]* # double quotes
)*
~
demo
Note that with this a little long pattern, the five items of your example string are found in only 60 steps. You can use this shorter/more simple pattern too:
~(?:[^'"\s]+|'[^']*'|"[^"]*")+~
but it's a little less efficient.
For your example, you can use preg_split with negative lookbehind (?<!\d), i.e.:
<?php
$str = "dateto:'2015-10-07 15:05' xxxx datefrom:'2015-10-09 15:05' yyyy asdf";
$matches = preg_split('/(?<!\d)(\s)/', $str);
print_r($matches);
Output:
Array
(
[0] => dateto:'2015-10-07 15:05'
[1] => xxxx
[2] => datefrom:'2015-10-09 15:05'
[3] => yyyy
[4] => asdf
)
Demo:
http://ideone.com/EP06Nt
Regex Explanation:
(?<!\d)(\s)
Assert that it is impossible to match the regex below with the match ending at this position (negative lookbehind) «(?<!\d)»
Match a single character that is a “digit” «\d»
Match the regex below and capture its match into backreference number 1 «(\s)»
Match a single character that is a “whitespace character” «\s»

Catching ids and its values from a string with preg_match

I was wondering how can I create preg_match for catching:
id=4
4 being any number and how can I search for the above example in a string?
If this is could be correct /^id=[0-9]/, the reason why I'm asking is because I'm not really good with preg_match.
for 4 being any number, we must set the range for it:
/^id\=[0-9]+/
\escape the equal-sign, plus after the number means 1 or even more.
You should go with the the following:
/id=(\d+)/g
Explanations:
id= - Literal id=
(\d+) - Capturing group 0-9 a character range between 0 and 9; + - repeating infinite times
/g - modifier: global. All matches (don't return on first match)
Example online
If you want to grab all ids and its values in PHP you could go with:
$string = "There are three ids: id=10 and id=12 and id=100";
preg_match_all("/id=(\d+)/", $string, $matches);
print_r($matches);
Output:
Array
(
[0] => Array
(
[0] => id=10
[1] => id=12
[2] => id=100
)
[1] => Array
(
[0] => 10
[1] => 12
[2] => 100
)
)
Example online
Note: If you want to match all you must use /g modifier. PHP doesn't support it but has other function for that which is preg_match_all. All you need to do is remove the g from the regex.

Difficulty with preg_match

I'm having some difficulty with preg_match. I'm trying to match roman numerals, like this:
$string='This is roman XI and some other ones: XMCIII, like this.XXVIII'."\n";
preg_match('/(\s|\.)M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})\s/',$string,$matches);
print_r($matches);
It should match any roman numeral preceded with whitespace or period and ending with whitespace. But it returns the following:
Array
(
[0] => XI
[1] =>
[2] =>
[3] => X
[4] => I
)
You have {0, 4} or {0,3} ranges in regex which means that those parts are optional. You get spaces because space[nothing]space becomes a valid match.
You can simply filter out the empty space results from your array using array_filter

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