PureBasic

Unzip a Text File Entry into a StringBuilder Using ZipEntry.UnzipToSb

See more Zip Examples

This example demonstrates how to use the ZipEntry.UnzipToSb method to inflate a text file entry directly into a StringBuilder object.

The ZIP entry is uncompressed entirely in memory and appended to the StringBuilder without creating a temporary file on disk.

This is useful when:

• Processing text files directly in memory
• Avoiding temporary filesystem files
• Reading configuration files, JSON, XML, CSV, or source code from ZIP archives
• Automatically converting line endings while inflating the text

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as:

• utf-8
• utf-16
• windows-1252

The lineEndingBehavior argument controls line-ending conversion:

• 0 — Leave line endings unchanged
• 1 — Convert all line endings to bare LF
• 2 — Convert all line endings to CRLF

Suppose the ZIP archive contains:

config/settings.json

The example inflates the JSON file directly into a StringBuilder.

PureBasic

IncludeFile "CkZipEntry.pb"
IncludeFile "CkZip.pb"
IncludeFile "CkStringBuilder.pb"

Procedure ChilkatExample()

    success.i = 0

    zip.i = CkZip::ckCreate()
    If zip.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Open an existing ZIP archive.
    success = CkZip::ckOpenZip(zip,"qa_data/zips/configFiles.zip")
    If success = 0
        Debug CkZip::ckLastErrorText(zip)
        CkZip::ckDispose(zip)
        ProcedureReturn
    EndIf

    ; Locate the JSON file entry within the ZIP archive.
    entry.i = CkZipEntry::ckCreate()
    If entry.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkZip::ckEntryOf(zip,"config/settings.json",entry)
    If success = 0
        Debug "ZIP entry not found."
        CkZip::ckCloseZip(zip)
        CkZip::ckDispose(zip)
        CkZipEntry::ckDispose(entry)
        ProcedureReturn
    EndIf

    ; ------------------------------------------------------------
    ; Inflate the ZIP entry directly into a StringBuilder.
    ; 
    ; The uncompressed text is appended to the StringBuilder.
    ; 
    sb.i = CkStringBuilder::ckCreate()
    If sb.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Leave line endings unchanged.
    lineEndingBehavior.i = 0

    ; Interpret the uncompressed bytes as UTF-8 text.
    srcCharset.s = "utf-8"

    success = CkZipEntry::ckUnzipToSb(entry,lineEndingBehavior,srcCharset,sb)
    If success = 0
        Debug CkZipEntry::ckLastErrorText(entry)
        CkZip::ckDispose(zip)
        CkZipEntry::ckDispose(entry)
        CkStringBuilder::ckDispose(sb)
        ProcedureReturn
    EndIf

    Debug "Uncompressed text:"
    Debug ""
    Debug CkStringBuilder::ckGetAsString(sb)

    CkZip::ckCloseZip(zip)

    Debug "Done."


    CkZip::ckDispose(zip)
    CkZipEntry::ckDispose(entry)
    CkStringBuilder::ckDispose(sb)


    ProcedureReturn
EndProcedure