$re = '/http:\/\/link\.2gis\.ru\/\d\.\d.*(https?.*")/siU';
$str = '{"meta":{"code":200,"api_version":"2.0.1.6.401","issue_date":"20171227"},"result":{"total":1,"items":[{"reg_bc_url":"https://stat.api.2gis.ru/?hash=zflyh9p8p7023113012GGG2c9j4x5x26G6G42466G57123H7rgewB419175IG1I1GAG5I4GJcz99uvG45446203472H1H4B2&v=2.0","name":"TechnoPoint, дисконт-центр","point":{"lat":55.754353,"lon":52.410458},"contact_groups":[{"contacts":[{"type":"phone","text":"8‒800‒700‒46‒66","value":"88007004666","comment":"круглосуточная единая справочная - пн-вс"},{"type":"website","text":"www.technopoint.ru","value":"http://link.2gis.ru/1.2/DEC186FE/online/20171201/project29/70000001022405020/2gis.ru/zflyh9p8p7023113016GGGba9j4x5x26G6G42466G57123H7rgewB419175IG1I1GAG5I4GJcz99uvG45446203472H1H4B2?http://www.technopoint.ru"},{"type":"vkontakte","text":"https://vk.com/technopoint_club","value":"https://vk.com/technopoint_club"},{"type":"odnoklassniki","text":"https://ok.ru/technopoint","value":"https://ok.ru/technopoint"}]}],"flags":{"photos":false},"name_ex":{"primary":"TechnoPoint","extension":"дисконт-центр"},"external_content":[{"type":"photo_album","count":3,"subtype":"view","main_photo_url":"https://i3.photo.2gis.com/main/geo/29/4082022817479773/view"}],"attribute_groups":[{"name":"Способы оплаты","attributes":[{"tag":"general_payment_type_cash","name":"Наличный расчет"},{"tag":"general_payment_type_bank","name":"Оплата через банк"},{"tag":"general_payment_type_internet","name":"Оплата через Интернет"}],"rubric_ids":[]}],"rubrics":[{"name":"Аудиотехника / Видеотехника","parent_id":"3","short_id":511,"alias":"audiotekhnika_videotekhnika","id":"511","kind":"primary"},{"name":"Бытовая техника","parent_id":"3","short_id":379,"alias":"bytovaya_tekhnika","id":"379","kind":"primary"},{"name":"Компьютеры / Комплектующие","parent_id":"3","short_id":181,"alias":"kompyutery_komplektuyushhie","id":"181","kind":"primary"},{"name":"Мобильные телефоны","parent_id":"19532","short_id":643,"alias":"mobilnye_telefony","id":"643","kind":"primary"}],"region_id":"29","adm_div":[{"id":"4082048587268177","name":"Новый Город","type":"living_area"}],"see_also":[{"name":"Matrix, торгово-сервисная фирма","main_photo_url":"https://i2.photo.2gis.com/main/branch/29/4081915443287042/common","point":{"lat":55.74556,"lon":52.436246},"name_ex":{"primary":"Matrix","extension":"торгово-сервисная фирма"},"stat":{"rubr":"181","adsalg":4,"adst":1514304900},"id":"4081915443287042_flyh9cz2G45446A263G3H1JJ7H889j4x5xzG4p8p702G43B2A0323033wB426G63A3G5GG455533A23H1I6H99uvrge19AB2I32H294J80224061","ads":{"text":"Гарантия качества, индивидуальный подход, постгарантийное обслуживание"},"address_comment":"2 этаж","address":{"postcode":"423815","components":[{"type":"street_number","number":"26","street":"53-й комплекс","street_id":"4082125896681047"}],"building_id":"4082022817470932"},"address_name":"53-й комплекс, 26","type":"branch","org":{"id":"4081924033221092","name":"Matrix, торгово-сервисная фирма","branch_count":1}},{"name":"Мобильный Рай, салон","point":{"lat":55.705664,"lon":52.346043},"name_ex":{"primary":"Мобильный Рай","extension":"салон"},"stat":{"rubr":"181","adsalg":4,"adst":1514304900},"id":"70000001028678031_flyh9cz2G45446AA241J25J3IH7H9j4x5xzG4p8p702G733117323032wB426G63A3G5GG3021298051G37H99uvrge19AB2I3H2H2B4H10224169f","ads":{"text":"Запчасти для вашего компьютера по низким ценам!","text_warning":"ИП Фащук Инга Робертовна, ОГРН 315165000018409","options":{"logo":{"img_url":"https://cdn.ams.2gis.com/a866c0ed-1c6c-4ff0-9e4b-91bb7a5177bf/8941283a0d615a4ce782501c23ebe61c7664e1aa/image.png","bg_color":"#2a85a5","text_color":"#FFFFFF"},"actions":[{"value":"http://link.2gis.ru/1.2/A2AACB71/online/20171201/project29/70000001028678031/2gis.ru/flyh9cz2G45446AA241J25J57HI69j4x5xzG4p8p703G733117323032wB426G63A3G5GG3021298051G37H99uvrge19AB2I3H2H2B4H1022416H87?https://www.mob-rai.ru/index.php?option=com_jshopping&controller=category&task=view&category_id=1&Itemid=117","name":"Посмотреть каталог","type":"link"}],"discount":true},"warning":"ИП Фащук Инга Робертовна, ОГРН 315165000018409"},"address_comment":"49 павильон; 1 этаж","address":{"postcode":"423803","components":[{"type":"street_number","number":"36","street":"Сергея Титова","street_id":"4082125896680005"}],"building_id":"4082022817472178","building_name":"Арзан"},"address_name":"Сергея Титова, 36","type":"branch","org":{"id":"70000001026553747","name":"Мобильный Рай, салон","branch_count":2}},{"name":"Radeon, выездной сервисный центр по ремонту и настройке компьютерной техники и мобильных устройств","point":{"lat":55.746473,"lon":52.416012},"name_ex":{"primary":"Radeon","extension":"выездной сервисный центр по ремонту и настройке компьютерной техники и мобильных устройств"},"stat":{"rubr":"181","adsalg":4,"adst":1514304900},"id":"4081915443292453_flyh9cz2G454465674G5HH3JI6I99j4x5xzG4p8p702G43B2A0323033wB426G63A3G5GG455533B23H17I599uvrge19AB2I32H294J802240616","ads":{"text":"Покупаем продаем ноутбуки, компьютеры и комплектующие.","options":{"logo":{"img_url":"https://cdn.ams.2gis.com/4bff868a-02e3-4d17-a588-ed72ffba65aa/3578d1b1f73e3354735e58920340afc6537d0c37/image.png","bg_color":"#228484","text_color":"#FFFFFF"},"discount":true}},"address_comment":"1 этаж; 4 подъезд","address":{"postcode":"423810","components":[{"type":"street_number","number":"16","street":"1-й комплекс","street_id":"4082125896679736"}],"building_id":"4082022817464710"},"address_name":"1-й комплекс, 16","type":"branch","org":{"id":"4081924033225363","name":"Radeon, выездной сервисный центр по ремонту и настройке компьютерной техники и мобильных устройств","branch_count":3}},{"name":"БелФорт, ООО, компания","point":{"lat":55.755859,"lon":52.407623},"name_ex":{"primary":"БелФорт, ООО","extension":"компания"},"stat":{"rubr":"181","adsalg":4,"adst":1514304900},"id":"4081915443407206_flyh9cz2G45446A427G6HH3JI6Ig9j4x5xzG4p8p702G43B2A0323033wB426G63A3G5GG455535223H17I599uvrge19AB2I32H294J80224061g","ads":{"text":"МФУ, копиры, принтеры. Продажа, обслуживание, ремонт","options":{"logo":{"img_url":"https://cdn.ams.2gis.com/61bfbe1d-f411-48f0-92b8-5678f4e34d7c/be49b7203a4a9e3d643bffbe4078d451ee6e77a3/image.png","bg_color":"#dc231c","text_color":"#FFFFFF"},"actions":[{"value":"http://link.2gis.ru/1.2/788B0BDE/online/20171201/project29/4081915443407206/2gis.ru/flyh9cz2G45446A427G6HH58IH7H9j4x5xzG4p8p703G43B2A0323033wB426G63A3G5GG455535223H17I599uvrge19AB2I32H294J80224061db?http://belfort.ru/Netshop/","name":"Выбрать по каталогу","type":"link"}],"discount":true}},"address_comment":"1 этаж","address":{"postcode":"423816","components":[{"type":"street_number","number":"35","street":"47-й комплекс","street_id":"4082125896680562"}],"building_id":"4082022817467768"},"address_name":"47-й комплекс, 35","type":"branch","org":{"id":"4081924033220711","name":"БелФорт, ООО, компания","branch_count":1}},{"name":"Гелиос, компания","point":{"lat":55.731386,"lon":52.395147},"name_ex":{"primary":"Гелиос","extension":"компания"},"stat":{"rubr":"181","adsalg":4,"adst":1514304900},"id":"4081915443307891_flyh9cz2G45446AAB2G7H1JJ7HBg9j4x5xzG4p8p702G43B2A0323033wB426G63A3G5GG455534223H1I6H99uvrge19AB2I32H294J80224061","ads":{"text":"Компьютеры, ноутбуки. Купите у нас – настроим, доставим бесплатно.","text_warning":"Подробности по тел. +7 (8552) 31–15–55.","warning":"Подробности по тел. +7 (8552) 31–15–55."},"address_comment":"2 этаж; 2 подъезд","address":{"postcode":"423812","components":[{"type":"street_number","number":"14а","street":"11-й комплекс","street_id":"4082125896679797"}],"building_id":"4082022817472116"},"address_name":"11-й комплекс, 14а","type":"branch","org":{"id":"4081924033217430","name":"Гелиос, компания","branch_count":1}}],"links":{"entrances":[{"id":"4082430871656427","geometry":{"points":["POINT(52.410294 55.754137)"],"normals":["LINESTRING(53.271311 55.245561,52.410294 55.754137)"],"vectors":["LINESTRING(52.410404 55.754072,52.410294 55.754137)"]},"is_primary":true}],"nearest_stations":[{"id":"4082173141319817","name":"45-й комплекс","distance":170,"route_types":["bus","shuttle_bus"]}]},"id":"70000001022405020","dates":{"created_at":"2016-04-04T06:00:00+03:00","updated_at":"2017-12-20T21:33:07+03:00"},"address_comment":"цокольный этаж","reviews":{"is_reviewable_on_flamp":true,"general_rating":2.5,"items":[{"tag":"flamp","rating":2.6,"review_count":5,"is_reviewable":true},{"tag":"foursquare","is_reviewable":true}],"org_review_count":5,"review_count":5,"rating":2.6,"org_rating":2.5,"general_review_count":5,"is_reviewable":true},"schedule":{"Thu":{"working_hours":[{"to":"21:00","from":"10:00"}]},"Sat":{"working_hours":[{"to":"21:00","from":"10:00"}]},"Tue":{"working_hours":[{"to":"21:00","from":"10:00"}]},"Sun":{"working_hours":[{"to":"21:00","from":"10:00"}]},"Mon":{"working_hours":[{"to":"21:00","from":"10:00"}]},"Wed":{"working_hours":[{"to":"21:00","from":"10:00"}]},"Fri":{"working_hours":[{"to":"21:00","from":"10:00"}]}},"address":{"postcode":"423816","components":[{"type":"street_number","number":"67в","street":"Сююмбике проспект","street_id":"4082125896679528"}],"building_id":"4082022817479773","building_name":"на Сююмбике"},"address_name":"Сююмбике проспект, 67в","type":"branch","org":{"id":"70000001022405019","name":"TechnoPoint, дисконт-центр","branch_count":1},"group":null}]}}';
$subst = "$1";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php