I'm trying to use preg_replace to search for a string but only replace a portion of the string, rather than the entire string, in a dynamic fashion.
For example, I am able to find the strings 'od', ':od', 'od:', '#od', and 'od ' with my code below. I want to replace only the 'od' portion with the word 'odometer' and leave the colon, hashtag, and white spaces untouched. However, the way that my current preg_replace is written would replace the colons and the hashtag in addition to the letters themselves. Any creative solutions to replace the characters only but preserve the surrounding symbols?
Thank you!
if(isset($_POST["text"]))
{
$original = $_POST["text"];
$abbreviation= array();
$abbreviation[0] = 'od';
$abbreviation[1] = 'rn';
$abbreviation[2] = 'ph';
$abbreviation[3] = 'real';
$translated= array();
$translated[0] ='odometer';
$translated[1] ='run';
$translated[2] ='pinhole';
$translated[3] ='fake';
function add_regex_finders($str){
return "/[\s:\#]" . $str . "[\s:]/i";
}
$original_parsed = array_map('add_regex_finders',$original);
preg_replace($original_parsed,$translated,$original);
}
You can add capture groups around the characters before and after the matched abbreviation, and then add the group references to the replacement string:
function add_regex_finders($str){
return "/([\s:\#])" . $str . "([\s:])/i";
}
$abbrevs_parsed = array_map('add_regex_finders', $abbreviation);
$translt_parsed = array_map(function ($v) { return '$1' . $v . '$2'; }, $translated);
echo preg_replace($abbrevs_parsed, $translt_parsed, $original);
Demo on 3v4l.org
Note you had a typo in your code, passing $original to the call to add_regex_finders when it should be $abbreviation.
Related
I am using Perl to do some prototyping.
I need an expression to replace e by [ee] if the string is exactly 2 chars and finishes by "e".
le -> l [ee]
me -> m [ee]
elle -> elle : no change
I cannot test the length of the string, I need one expression to do the whole job.
I tried:
`s/(?=^.{0,2}\z).*e\z%/[ee]/g` but this is replacing the whole string
`s/^[c|d|j|l|m|n|s|t]e$/[ee]/g` same result (I listed the possible letters that could precede my "e")
`^(?<=[c|d|j|l|m|n|s|t])e$/[ee]/g` but I have no match, not sure I can use ^ on a positive look behind
EDIT
Guys you're amazing, hours of search on the web and here I get answers minutes after I posted.
I tried all your solutions and they are working perfectly directly in my script, i.e. this one:
my $test2="le";
$test2=~ s/^(\S)e$/\1\[ee\]/g;
print "test2:".$test2."\n";
-> test2:l[ee]
But I am loading these regex from a text file (using Perl for proto, the idea is to reuse it with any language implementing regex):
In the text file I store for example (I used % to split the line between match and replace):
^(\S)e$% \1\[ee\]
and then I parse and apply all regex like that:
my $test="le";
while (my $row = <$fh>) {
chomp $row;
if( $row =~ /%/){
my #reg = split /%/, $row;
#if no replacement, put empty string
if($#reg == 0){
push(#reg,"");
}
print "reg found, reg:".$reg[0].", replace:".$reg[1]."\n";
push #regs, [ #reg ];
}
}
print "orgine:".$test."\n";
for my $i (0 .. $#regs){
my $p=$regs[$i][0];
my $r=$regs[$i][1];
$test=~ s/$p/$r/g;
}
print "final:".$test."\n";
This technique is working well with my other regex, but not yet when I have a $1 or \1 in the replace... here is what I am obtaining:
final:\1\ee\
PS: you answered to initial question, should I open another post ?
Something like s/(?i)^([a-z])e$/$1[ee]/
Why aren't you using a capture group to do the replacement?
`s/^([c|d|j|l|m|n|s|t])e$/\1 [ee]/g`
If those are the characters you need and if it is indeed one word to a line with no whitespace before it or after it, then this will work.
Here's another option depending on what you are looking for. It will match a two character string consisting of one a-z character followed by one 'e' on its own line with possible whitespace before or after. It will replace this will the single a-z character followed by ' [ee]'
`s/^\s*([a-z])e\s*$/\1 [ee]/`
^(\S)e$
Try this.Replace by $1 [ee].See demo.
https://regex101.com/r/hR7tH4/28
I'd do something like this
$word =~ s/^(\w{1})(e)$/$1$2e/;
You can use following regex which match 2 character and then you can replace it with $1\[$2$2\]:
^([a-zA-Z])([a-zA-Z])$
Demo :
$my_string =~ s/^([a-zA-Z])([a-zA-Z])$/$1[$2$2]/;
See demo https://regex101.com/r/iD9oN4/1
I want to get data between delimiters and include the delimiters in the match.
Example text:
>>> Possible error is caused by the segmentation fault
provided detection report:
<detection-report>
This is somthing that already in the report.
just an example report.
</detection-report>
---------------------------------------------
have a nice day
My current code is:
if($oopsmessage =~/(?<=<detection-report>)((.|\n|\r|\s)+)(?=<\/detection-report>)/) {
$this->{'detection_report'} = $1;
}
It retrieves the following:
This is something that already in the report.
just an example report.
How can i include both the detection-report delimiters?
You can simplify the regex to the following:
my ($report) = $oopsmessage =~ m{(<detection-report>.*?</detection-report>)}s;
Notice I used a different delimiters to avoid the "leaning toothpick syndrome".
The s modifier makes . match newlines.
The parentheses in ($report) force list context, so the match returns all the matching groups. $1 is therefore assigned to $report.
(<detection-report>(?:(?!<\/detection-report>).)*<\/detection-report>)
Try this.Put flags g and s.See demo.
http://regex101.com/r/xT7yD8/18
Just do:
if ($oopsmessage =~ #(<detection-report>[\s\S]+?</detection-report>#) {
$this->{'detection_report'} = $1;
}
or, if you're dreading a file line by line:
while(<$fh>) {
if (/<detection-report>/ .. /<\/detection-report>/) {
$this->{'detection_report'} .= $_;
}
}
Use the below regex to get the data with delimiters.
(<detection-report>[\S\s]+?<\/detection-report>)
Group index 1 contains the string you want.
DEMO
[\S\s] would match one or more space or non-space characters.
/(<detection-report>.*?<\/detection-report>)/gs
You can simplify your regex to the following:
if($oopsmessage =~ m#(<detection-report>.+</detection-report>)#s) {
$this->{'detection_report'} = $1;
}
say $this->{'detection_report'};
Using the modifiers s allows a multiline match where . can be a new line. Using # instead of / means no faffing around with escaping slashes.
Output:
<detection-report>
This is somthing that already in the report.
just an example report.
</detection-report>
I want to match two string which differ only in element and newlines
$string1 = "perl is <match>scripting language</match>";
$string2 = "perl<TAG> is<TAG> scr<TAG>ipt<TAG>inglanguage";
Note: spaces and <TAG> and newline can come anywhere in string2. space may or may not present in string2 for e.g. in above instance in $string2 spaces between words scripting language is missing. we have to ignore space,tags,newline while matching string1 against string2. <match> tag in string1 indicates the data to be matched against string2
output required :
whole content of string2 in addition with <match> tag.
perl<TAG> is<TAG> <match>scr<TAG>ipt<TAG>inglanguage</match>
Code i tried :
while($string =~ /<match>(.*?)<\/match>/gs)
{
my $data_to_match = $1;
$data_to_match = add_pat($data_to_match);
$string2 =~ s{($data_to_match)}
{
"<match>$&<\/match>"
}esi;
}
sub add_pat
{
my ($data) = (#_);
my #array = split//,$data;
foreach my $each(#array)
{
$each = quotemeta $each;
$each = '(?:(<TAG>|\s)+)?'.$each.'(?:(<TAG>|\s)+)?';
}
$data = join '',#array;
return $data;
}
Problem : since space is missing in string2 it is not matching.i tried making space optional while appending pattern to each character. but making space optional. $string pattern goes on running.
In reality, i have large string to match. these space is causing problem..Please suggest
Use regular expressions to remove all the characters that you wish to ignore from both of the strings. Then compare the remaining values of the two strings.
So you will end up both strings, for example:
'perlisscriptinglanguage' and 'perlisscriptinglanguage'
If you want you can also upper/lower case them to match too.
If they match then just return the original string 2.
I think its weird that you are expected to "match". but $string2, if you take out the tags, doesnt match the original string.
Anyway, since your code is tolerant of Additional spaces and tags in $string2, then you can wipe all spaces (and tags if applicable) from $string1.
I added $data_to_match =~ s/ +//; before your call to add_pat. That didnt quite work because this line "$each = '(?:(|\s)+)?'.$each.'(?:(|\s)+)?';" adds the (?:(|\s)+)?' even before your first letter of the match from $string1. You actually have a lot of redundant TAG patterns, you add one to the front and back of each letter. I dont know what quotemeta does so im not sure how to fix the code there. I just added
$data_to_match =~ s/\Q(?:(<TAG>|\s)+)?\E//; line after the call to add_pat to strip off the first TAG pattern from the front of the pattern. otherwise it'll match wrong and output this 'perl < TAG> is< match>< TAG> scr< TAG>ipt< TAG>inglanguage< /match>'
Really you should only be putting one "(?:(|\s)+)?" inbetween each letter of the $string1 match, and more importantly; you should not be putting "(?:(|\s)+)?" before the first letter or after the last letter.
I have this little script:
my #list = ('R3_05_foo.txt','T3_12_foo_bar.txt','01.txt');
foreach (#list) {
s/(\d{2}).*\.txt$/$1.txt/;
s/^0+//;
print $_ . "\n";
}
The expected output would be
5.txt
12.txt
1.txt
But instead, I get
R3_05.txt
T3_12.txt
1.txt
The last one is fine, but I cannot fathom why the regex gives me the string start for $1 on this case.
Try this pattern
foreach (#list) {
s/^.*?_?(?|0(\d)|(\d{2})).*\.txt$/$1.txt/;
print $_ . "\n";
}
Explanations:
I use here the branch reset feature (i.e. (?|...()...|...()...)) that allows to put several capturing groups in a single reference ( $1 here ). So, you avoid using a second replacement to trim a zero from the left of the capture.
To remove all from the begining before the number, I use :
.*? # all characters zero or more times
# ( ? -> make the * quantifier lazy to match as less as possible)
_? # an optional underscore
Note that you can ensure that you have only 2 digits adding a lookahead to check if there is not a digit that follows:
s/^.*?_?(?|0(\d)|(\d{2}))(?!\d).*\.txt$/$1.txt/;
(?!\d) means not followed by a digit.
The problem here is that your substitution regex does not cover the whole string, so only part of the string is substituted. But you are using a rather complex solution for a simple problem.
It seems that what you want is to read two digits from the string, and then add .txt to the end of it. So why not just do that?
my #list = ('R3_05_foo.txt','T3_12_foo_bar.txt','01.txt');
for (#list) {
if (/(\d{2})/) {
$_ = "$1.txt";
}
}
To overcome the leading zero effect, you can force a conversion to a number by adding zero to it:
$_ = 0+$1 . ".txt";
I would modify your regular expression. Try using this code:
my #list = ('R3_05_foo.txt','T3_12_foo_bar.txt','01.txt');
foreach (#list) {
s/.*(\d{2}).*\.txt$/$1.txt/;
s/^0+//;
print $_ . "\n";
}
The problem is that the first part in your s/// matches, what you think it does, but that the second part isn't replacing what you think it should. s/// will only replace what was previously matched. Thus to replace something like T3_ you will have to match that too.
s/.*(\d{2}).*\.txt$/$1.txt/;
I have a question I am hoping someone could help with...
I have a variable that contains the content from a webpage (scraped using WWW::Mechanize).
The variable contains data such as these:
$var = "ewrfs sdfdsf cat_dog,horse,rabbit,chicken-pig"
$var = "fdsf iiukui aawwe dffg elephant,MOUSE_RAT,spider,lion-tiger hdsfds jdlkf sdf"
$var = "dsadp poids pewqwe ANTELOPE-GIRAFFE,frOG,fish,crab,kangaROO-KOALA sdfdsf hkew"
The only bits I am interested in from the above examples are:
#array = ("cat_dog","horse","rabbit","chicken-pig")
#array = ("elephant","MOUSE_RAT","spider","lion-tiger")
#array = ("ANTELOPE-GIRAFFE","frOG","fish","crab","kangaROO-KOALA")
The problem I am having:
I am trying to extract only the comma-separated strings from the variables and then store these in an array for use later on.
But what is the best way to make sure that I get the strings at the start (ie cat_dog) and end (ie chicken-pig) of the comma-separated list of animals as they are not prefixed/suffixed with a comma.
Also, as the variables will contain webpage content, it is inevitable that there may also be instances where a commas is immediately succeeded by a space and then another word, as that is the correct method of using commas in paragraphs and sentences...
For example:
Saturn was long thought to be the only ringed planet, however, this is now known not to be the case.
^ ^
| |
note the spaces here and here
I am not interested in any cases where the comma is followed by a space (as shown above).
I am only interested in cases where the comma DOES NOT have a space after it (ie cat_dog,horse,rabbit,chicken-pig)
I have a tried a number of ways of doing this but cannot work out the best way to go about constructing the regular expression.
How about
[^,\s]+(,[^,\s]+)+
which will match one or more characters that are not a space or comma [^,\s]+ followed by a comma and one or more characters that are not a space or comma, one or more times.
Further to comments
To match more than one sequence add the g modifier for global matching.
The following splits each match $& on a , and pushes the results to #matches.
my $str = "sdfds cat_dog,horse,rabbit,chicken-pig then some more pig,duck,goose";
my #matches;
while ($str =~ /[^,\s]+(,[^,\s]+)+/g) {
push(#matches, split(/,/, $&));
}
print join("\n",#matches),"\n";
Though you can probably construct a single regex, a combination of regexs, splits, grep and map looks decently
my #array = map { split /,/ } grep { !/^,/ && !/,$/ && /,/ } split
Going from right to left:
Split the line on spaces (split)
Leave only elements having no comma at the either end but having one inside (grep)
Split each such element into parts (map and split)
That way you can easily change the parts e.g. to eliminate two consecutive commas add && !/,,/ inside grep.
I hope this is clear and suits your needs:
#!/usr/bin/perl
use warnings;
use strict;
my #strs = ("ewrfs sdfdsf cat_dog,horse,rabbit,chicken-pig",
"fdsf iiukui aawwe dffg elephant,MOUSE_RAT,spider,lion-tiger hdsfds jdlkf sdf",
"dsadp poids pewqwe ANTELOPE-GIRAFFE,frOG,fish,crab,kangaROO-KOALA sdfdsf hkew",
"Saturn was long thought to be the only ringed planet, however, this is now known not to be the case.",
"Another sentence, although having commas, should not confuse the regex with this: a,b,c,d");
my $regex = qr/
\s #From your examples, it seems as if every
#comma separated list is preceded by a space.
(
(?:
[^,\s]+ #Now, not a comma or a space for the
#terms of the list
, #followed by a comma
)+
[^,\s]+ #followed by one last term of the list
)
/x;
my #matches = map {
$_ =~ /$regex/;
if ($1) {
my $comma_sep_list = $1;
[split ',', $comma_sep_list];
}
else {
[]
}
} #strs;
$var =~ tr/ //s;
while ($var =~ /(?<!, )\b[^, ]+(?=,\S)|(?<=,)[^, ]+(?=,)|(?<=\S,)[^, ]+\b(?! ,)/g) {
push (#arr, $&);
}
the regular expression matches three cases :
(?<!, )\b[^, ]+(?=,\S) : matches cat_dog
(?<=,)[^, ]+(?=,) : matches horse & rabbit
(?<=\S,)[^, ]+\b(?! ,) : matches chicken-pig