(Tcl) Chilkat Zip API Concepts

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

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load ./chilkat.dll

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

set zip [new_CkZip]

# 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.
set success [CkZip_NewZip $zip "test.zip"]
if {$success != 1} then {
    puts [CkZip_lastErrorText $zip]
    delete_CkZip $zip
    exit
}

# The FileName property should now contain "test.zip".  This is the name of the .zip
# that is written when WriteZip or WriteZipAndClose is called.
puts "zip filename = [CkZip_fileName $zip]"

# 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
set saveExtraPath 0
set success [CkZip_AppendOneFileOrDir $zip "/temp/abc123/HelloWorld123.txt" $saveExtraPath]
if {$success != 1} then {
    puts [CkZip_lastErrorText $zip]
    delete_CkZip $zip
    exit
}

# 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
set entry [CkZip_GetEntryByIndex $zip 0]
CkZipEntry_put_FileName $entry "helloWorld.txt"
delete_CkZipEntry $entry

# 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:
set entry [CkZip_AppendString2 $zip "HelloWorld2.txt" "hello world!" "utf-8"]
delete_CkZipEntry $entry

# 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. 

set n [CkZip_get_NumEntries $zip]
for {set i 0} {$i <= [expr $n - 1]} {incr i} {

    set entry [CkZip_GetEntryByIndex $zip $i]
    puts [CkZipEntry_fileName $entry], type=[CkZipEntry_get_EntryType $entry]
    delete_CkZipEntry $entry

}

# Write the "test.zip" file.
set success [CkZip_WriteZip $zip]
if {$success != 1} then {
    puts [CkZip_lastErrorText $zip]
    delete_CkZip $zip
    exit
}

# 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:

set n [CkZip_get_NumEntries $zip]
for {set i 0} {$i <= [expr $n - 1]} {incr i} {

    set entry [CkZip_GetEntryByIndex $zip $i]
    puts [CkZipEntry_fileName $entry], type=[CkZipEntry_get_EntryType $entry]
    delete_CkZipEntry $entry

}

# Finally, close the zip
CkZip_CloseZip $zip

delete_CkZip $zip