---
name: "pcre2_substring_get_bynumber"
section: "3"
platform: "linux"
package: "pcre2"
version: "10.49-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pcre2_substring_get_bynumber"
---

# pcre2\_substring\_get\_bynumber(3)

Perl-compatible regular expressions (revised API)

## NAME

PCRE2 - Perl-compatible regular expressions (revised API)

## SYNOPSIS

**#include \<pcre2.h\>**

```
int pcre2_substring_get_bynumber(pcre2_match_data *match_data,
  uint32_t number, PCRE2_UCHAR **bufferptr, PCRE2_SIZE *bufflen);
```

## DESCRIPTION

This is a convenience function for extracting a captured substring by number into newly acquired memory. The arguments are:

  *match\_data*    The match data for the match\
   *number*        Number of the required substring\
   *bufferptr*     Where to put the string pointer\
   *bufflen*       Where to put the string length

The memory in which the substring is placed is obtained by calling the same memory allocation function that was used for the match data block. The convenience function **pcre2\_substring\_free()** can be used to free it when it is no longer needed. The yield of the function is zero for success or one of the following error numbers:

  PCRE2\_ERROR\_NOSUBSTRING   there are no groups of that number\
   PCRE2\_ERROR\_UNAVAILBLE    the ovector was too small for that group\
   PCRE2\_ERROR\_UNSET         the group did not participate in the match\
   PCRE2\_ERROR\_NOMEMORY      memory could not be obtained

There is a complete description of the PCRE2 native API in the **pcre2api** page and a description of the POSIX API in the **pcre2posix** page.