---
name: "DlpReadAppBlock"
section: "3"
platform: "linux"
package: "coldsync"
version: "3.0+pre3-3"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/DlpReadAppBlock"
---

# DlpReadAppBlock(3)

manipulate special blocks in Palm databases

## NAME

**DlpReadAppBlock**, **DlpWriteAppBlock**, **DlpReadSortBlock**, **DlpWriteSortBlock** – manipulate special blocks in Palm databases

## LIBRARY

*libpconn*

## SYNOPSIS

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

**#include \<pconn/pconn.h\>**

*int*\

**DlpReadAppBlock**(*PConnection \*pconn*, *const ubyte handle*, *const uword offset*, *const uword len*, *uword \*size*, *const ubyte \*\*data*);

*int*\

**DlpWriteAppBlock**(*PConnection \*pconn*, *const ubyte handle*, *const uword len*, *const ubyte \*data*);

*int*\

**DlpReadSortBlock**(*PConnection \*pconn*, *const ubyte handle*, *const uword offset*, *const uword len*, *uword \*size*, *const ubyte \*\*data*);

*int*\

**DlpWriteSortBlock**(*PConnection \*pconn*, *const ubyte handle*, *const uword len*, *const ubyte \*data*);

## DESCRIPTION

**DlpReadAppBlock** reads the AppInfo block of a database on the Palm. The database must already be open for reading.

*handle* is the database handle given by **DlpOpenDB**.

*offset* indicates the offset at which to start reading. This should be 0 to read from the beginning of the AppInfo block.

*len* indicates the maximum number of bytes to read.

*size* is filled in with the number of bytes actually read.

*data* is filled in with a pointer to a buffer containing the data read. This buffer is volatile, so the data should be copied before the next DLP function call.

**DlpWriteAppBlock** writes a database's AppInfo block. If the database already had an AppInfo block, it is erased.

*handle* is the database handle given by **DlpOpenDB**.

*len* specifies the length of the new AppInfo block.

*data* is a pointer to the new AppInfo block.

**DlpReadSortBlock** and **DlpWriteSortBlock** are similar to **DlpReadAppBlock** and **DlpWriteAppBlock**, but affect the database's sort block instead of its AppInfo block.

## RETURN VALUE

## SEE ALSO

[libpconn(3)](/libpconn/3.md), DlpOpenDB.