---
name: "RtlPrefixString"
section: "3w"
platform: "linux"
package: "libwine-dev"
version: "1.4.1-4"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/RtlPrefixString"
---

# RtlPrefixString(3w)

## NAME

**RtlPrefixString** (NTDLL.@)

## SYNOPSIS

BOOLEAN RtlPrefixString\
  (\
   const STRING\* *s1*,\
   const STRING\* *s2*,\
   BOOLEAN       *ignore\_case*\
  )

## DESCRIPTION

Determine if one string is a prefix of another.

## PARAMS

*s1* **\[In\]**  Prefix to look for in *s2*.

*s2* **\[In\]**  String that may contain *s1* as a prefix.

*ignore\_case* **\[In\]**  **TRUE** = Case insensitive, **FALSE** = Case sensitive.

## RETURNS

**TRUE** if *s2* contains *s1* as a prefix, **FALSE** otherwise.

## IMPLEMENTATION

Declared in **"winternl.h"**.

Implemented in **"dlls/ntdll/rtlstr.c"**.

Debug channel **"ntdll"**.