Estrarre con le funzioni del API di libzip i file contenuti da un file compresso .zip
Da Gambas-it.org - Wikipedia.
Versione del 18 mag 2023 alle 07:47 di Vuott (Discussione | contributi)
La libreria libzip consente di gestire file compressi .zip.
Per poter fruire in gambas delle risorse della libreria libzip, è necessario installare e richiamare la libreria condivisa: "libzip.so.5.0 "
Mostriamo un esempio pratico per estrarre uno o più file contenuti in un file compresso .zip:
Library "libzip:5.0"
Public Struct zip_stat
valid As Long
name As Pointer
index As Long
size As Long
comp_size As Long
mtime As Long
crc As Integer
comp_method As Short
encryption_method As Short
flags As Integer
End Struct
' struct zip *zip_open(const char *, int, int *)
' Open zip archive.
Private Extern zip_open(path As String, flags As Integer, errorp As Pointer) As Pointer
' zip_int64_t zip_get_num_entries(zip_t *, zip_flags_t)
' Get number of files in archive.
Private Extern zip_get_num_entries(archive As Pointer, flags As Integer) As Long
' int zip_stat_index(struct zip *, int, int, struct zip_stat *)
' Get information about file by index.
Private Extern zip_stat_index(archive As Pointer, index As Integer, flags As Integer, sb As Zip_stat) As Integer
' struct zip_file * zip_fopen_index(struct zip *, int, int)
' Open file in zip archive for reading by index
Private Extern zip_fopen_index(archive As Pointer, index As Integer, flags As Integer) As Pointer
' zip_int64_t zip_fread(struct zip_file *, void *, zip_uint64_t)
' Read from file.
Private Extern zip_fread(zfile As Pointer, buf As Byte[], nbytes As Long) As Long
' int zip_fclose(struct zip_file *)
' Close file in zip archive.
Private Extern zip_fclose(zfile As Pointer) As Integer
' int zip_close(struct zip *)
' Close zip archive.
Private Extern zip_close(archive As Pointer) As Integer
Public Sub Main()
Dim percorsoZip, decompresso As String
Dim z, zf As Pointer
Dim i, lun As Integer
Dim zs As New Zip_stat
Dim l As Long
Dim fl As File
Dim buf As New Byte[64]
percorsoZip = "/percorso/del/file.zip"
decompresso = "/percorso/ove/saranno/estratti/i/file"
z = zip_open(percorsoZip, 0, 0)
If z == 0 Then
zip_close(z)
Error.Raise("Impossibile aprire un file '.zip' !")
Endif
For i = 0 To zip_get_num_entries(z, 0) - 1
If zip_stat_index(z, i, 0, zs) = 0 Then
lun = Len(String@(zs.name))
Print "Nome: "; String@(zs.name)
Print "Dimensione: "; zs.size
Print "mtime: "; zs.mtime
If Right(String@(zs.name), 1) = "/" Then
Continue
Else
zf = zip_fopen_index(z, i, 0)
If zf == 0 Then
zip_fclose(zf)
Error.Raise("Errore alla funzione 'zip_fopen_index()' !")
Endif
fl = Open decompresso &/ File.Name(String@(zs.name)) For Create
While l < zs.size
lun = zip_fread(zf, buf, 64)
If lun < 0 Then Error.Raise("Errore nella lettura del file !")
buf.Write(fl, 0, lun)
l += lun
Wend
fl.Close
zip_fclose(zf)
Endif
Endif
Next
zip_close(z)
End
