---
name: "pcre2_set_substitute_callout"
section: "3"
platform: "linux"
package: "pcre2"
version: "10.49-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pcre2_set_substitute_callout"
---

# pcre2\_set\_substitute\_callout(3)

Perl-compatible regular expressions (revised API)

## NAME

PCRE2 - Perl-compatible regular expressions (revised API)

## SYNOPSIS

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

```
int pcre2_set_substitute_callout(pcre2_match_context *mcontext,
  int (*callout_function)(pcre2_substitute_callout_block *, void *),
  void *callout_data);
```

## DESCRIPTION

This function sets the substitute callout fields in a match context (the first argument). The second argument specifies a callout function, and the third argument is an opaque data item that is passed to it. The result of this function is always zero.

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.