Chapter 6 Adding Files to an Archive

6.1 Writable formats

Only ZIP, 7Z and the TAR family (including compressed variants like TAR.GZ) support adding: with such an archive open, the toolbar “Add Files / Add Folder / Save” buttons are enabled. Read-only formats (RAR, PKG, CAB, ISO, installers) disable the add buttons; single-file streams (GZ / BZ2 / XZ / ZST) have no entries at all and are not writable either.

6.2 Adding files and folders

Three entry points:

• “Actions → Add Files” / “Actions → Add Folder”.
• The toolbar “Add Files” / “Add Folder” buttons.
• Drag and drop files/folders onto the window of an open writable archive.

Added entries first go to the pending list: rows marked with “+” appear at the end of the file table (no checkboxes); right-click “Remove” withdraws a pending entry. The archive on disk is untouched at this point.

6.3 Saving

Click the toolbar “Save” to write the pending entries into the archive:

• ZIP: a true append — only the central directory is rewritten, it completes in seconds.
• 7Z / TAR family: compressed streams cannot be appended, so WxArc rewrites the whole archive (temp file + atomic replace). Old entries are copied streamingly, so large archives take time proportional to their size; a 7Z rewrite converts old entries to LZMA2 (original PPMd and other codings are lost).

After a successful save the archive reloads automatically, preserving expansion state and selection. If old entries are encrypted and the password is missing, a password dialog appears (“The archive contains encrypted data. A password is required to add files.”).

6.4 Notes

• Same-name entries are not deduplicated: they are appended, and the conflict dialog covers them at extraction time (see 4.5).
• Adding to large 7Z / TAR archives is a full rewrite — please wait for the progress dialog to finish.