(Ruby) Chilkat Zip API Concepts

This example helps clarify some common misconceptions w/ using the Chilkat Zip API.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

zip = Chilkat::CkZip.new()

# To clarify some concepts, this example will create a new .zip containing 2 files.

# The NewZip method is called to initialize the zip object to a new and empty state.
# It does not actually create the .zip file.  It simply intializes the object.
# if the zip object did not contain anything previously, then this method could be skipped
# altogether.  It has the side-effect of setting the zip.FileName property.
success = zip.NewZip("test.zip")
if (success != true)
    print zip.lastErrorText() + "\n";
    exit
end

# The FileName property should now contain "test.zip".  This is the name of the .zip
# that is written when WriteZip or WriteZipAndClose is called.
print "zip filename = " + zip.fileName() + "\n";

# When a file is "appended" to the zip object, we are really just appending a reference
# to the file in the filesystem.  A "zip entry" is added to the zip object and this entry
# can be one of several types.  It can point to a file.  It can contain uncompressed binary
# or text data, it can point to an entry in the already-opened zip (if we had called OpenZip 
# instead), etc.  

# Now.. add a reference to a single file by calling AppendOneFileOrDir
# Note: On Windows, forward slashes are equivalent to backslashes
saveExtraPath = false
success = zip.AppendOneFileOrDir("/temp/abc123/HelloWorld123.txt",saveExtraPath)
if (success != true)
    print zip.lastErrorText() + "\n";
    exit
end

# We now have a zip object with one entry, which points to the file /temp/abc123/HelloWorld123.txt
# If desired, we could change the filename of the zip entry so that when the zip is written,
# the file has a different name:
# entry is a CkZipEntry
entry = zip.GetEntryByIndex(0)
entry.put_FileName("helloWorld.txt")

# When the zip is actually written, the entry's data will stream from /temp/abc123/HelloWorld123.txt
# and be compressed into an entry within the .zip having the filename "helloWorld.txt"

# Now add another entry, this time from a string containing the file content:
# entry is a CkZipEntry
entry = zip.AppendString2("HelloWorld2.txt","hello world!","utf-8")

# Examine the entries in the zip so far..
# Each entry can be one of the following types:

# 0 -- Mapped Entry: An entry in an existing Zip file.
# 1 -- File Entry: A file not yet in memory, but referenced. 
#      These entries are added by calling AppendFiles, AppendFilesEx, AppendOneFileOrDir, etc.
# 2 -- Data Entry: An entry containing uncompressed data from memory. 
#      These entries are added by calling AppendData, AppendString, etc.
# 3 -- Null Entry: An entry that no longer exists in the .zip.
# 4 -- New Directory Entry: A directory entry added by calling AppendNewDir. 

n = zip.get_NumEntries()
for i in 0 .. n - 1

    # entry is a CkZipEntry
    entry = zip.GetEntryByIndex(i)
    print entry.fileName() + ", type=" + entry.get_EntryType().to_s() + "\n";

end

# Write the "test.zip" file.
success = zip.WriteZip()
if (success != true)
    print zip.lastErrorText() + "\n";
    exit
end

# Our zip object still contains 2 entries, but now they point to the entries within the 
# test.zip  (We called WriteZip, which writes the .zip but does not close it.  Instead,
# the entries of the zip object are updated to become "mapped" entries.
# For example:

n = zip.get_NumEntries()
for i in 0 .. n - 1

    # entry is a CkZipEntry
    entry = zip.GetEntryByIndex(i)
    print entry.fileName() + ", type=" + entry.get_EntryType().to_s() + "\n";

end

# Finally, close the zip
zip.CloseZip()