| title | MOUNT-ZIP |
|---|---|
| section | 1 |
| header | User Manual |
| footer | mount-zip 1.13 |
| date | May 2026 |
mount-zip - Mount ZIP archives as FUSE file systems.
- mount-zip [options] zip-file
- mount-zip [options] zip-file mount-point
- mount-zip [options] zip-file-1 zip-file-2 ... mount-point
mount-zip mounts one or several ZIP archives as a read-only FUSE file system. It starts quickly, uses little memory, decodes encrypted files, and provides on-the-go decompression and caching for maximum efficiency.
mount-zip automatically creates the target mount point if needed. If no mount point is specified, mount-zip creates a mount point in the current working directory.
--help or -h : Print help.
--version or -V : Print program version.
-o quiet or -q : Print fewer log messages.
-o verbose or -v : Print more detailed log messages.
-o redact : Redact file names from log messages.
-o force : Continue even if the given password is wrong or missing, or if the encryption or compression method is unsupported.
-o precache : Preemptively decompress and cache the whole ZIP archive(s).
-o cache=DIR
: Use a different cache directory (default is $TMPDIR or /tmp).
-o memcache : Cache the decompressed data in memory.
-o nocache : Do not cache the decompressed data.
-o encoding=CHARSET : Original encoding of file names.
-o notrim : Do not trim the base of the tree. Keep all the intermediate directories as specified in the ZIP archive(s).
-o nomerge : Do not merge multiple ZIP archives on top of each other. Instead, create a subdirectory for each ZIP archive inside the mount point.
-o nodirs : No directories. Flatten the archive structure by presenting all its files in its root directory. This might make sense if you're not interested in the archive tree structure, but only in its file data, e.g. for malware scanning.
-o nospecials : Hide special files (FIFOs, sockets, devices).
-o nosymlinks : Hide symbolic links.
-o nohardlinks : Hide hard links.
-o dmask=M : Directory permission mask in octal (default 0022).
-o fmask=M : File permission mask in octal (default 0022).
-o uid=N : Set the user ID of all the items in the mounted archive (default is current user).
-o gid=N : Set the group ID of all the items in the mounted archive (default is current group).
-o default_permissions : Use the user ID, group ID and permissions stored with each item in the archive.
-f : Foreground mode.
-d : Foreground mode with debug output.
Mount a ZIP archive:
$ mount-zip foobar.zip mnt
The mounted ZIP archive can be explored and read using any application:
$ tree mnt
mnt
└── foo
0 directories, 1 file
$ cat mnt/foo
bar
When finished, unmount the file system:
$ umount mnt
- Read-only view
- Instant mounting, even with big ZIP archives
- Compression methods: deflate, bzip2
- Encryption methods: AES and legacy ZIP encryption
- Asks for decryption password if necessary
- Detects file name encoding
- Converts file names to Unicode UTF-8
- Deduplicates files in case of name collisions
- Unpacks files when reading them (on-the-go decompression)
- Supports all file types, including named sockets, FIFOs, block and character devices, symbolic links and hard links
- Supports Unix access modes and DOS file permissions
- Supports owner and group information (UID and GID)
- Supports relative and absolute paths
- Supports high-precision timestamps
- Works on 32-bit and 64-bit devices
- Supports ZIP64 extensions, even on 32-bit devices:
- Supports ZIP archives containing more than 65,535 files
- Supports ZIP archives and files bigger than 4 GB
- Supports the following ZIP format extensions:
- 000A PKWARE NTFS high-precision timestamps
- 000D PKWARE Unix file type
- 5455 Unix timestamps
- 5855 Info-ZIP Unix extra fields (type 1)
- 7855 Info-ZIP Unix extra fields (type 2)
- 7875 Info-ZIP Unix extra fields (type 3): UID and GID
mount-zip is fully Unicode compliant. It converts the file names stored in the ZIP archive from their original encoding to UTF-8.
In order to interpret these file names correctly, mount-zip needs to determine their original encoding. By default mount-zip tries to guess this encoding using the detection feature provided by the ICU library. It can automatically recognize the following encodings:
- UTF-8
- CP437
- Shift JIS
- Big5
- EUC-JP
- EUC-KR
- GB18030
- ISO-2022-CN
- ISO-2022-JP
- ISO-2022-KR
- KOI8-R
For example, when mounting a ZIP containing a Shift JIS-encoded file name, the encoding is correctly detected:
$ mount-zip sjis-filename.zip mnt
$ tree mnt
mnt
└── 新しいテキスト ドキュメント.txt
0 directories, 1 file
This system is not foolproof, and doesn't recognize a number of popular encodings. For example, when mounting a ZIP containing file names encoded in CP866, they are interpreted as CP437 and rendered as Mojibake:
$ mount-zip cp866.zip mnt
$ tree mnt
mnt
├── äáΓá
└── ÆѬßΓ«óδ⌐ ñ«¬π¼Ñ¡Γ.txt
0 directories, 2 files
In this case, the user needs to explicitly specify the original file name
encoding using the -o encoding mount option:
$ mount-zip -o encoding=cp866 cp866.zip mnt
$ tree mnt
mnt
├── Дата
└── Текстовый документ.txt
0 directories, 2 files
In case of name collision, mount-zip adds a number to deduplicate the conflicting file name:
$ unzip -l file-dir-same-name.zip
Length Date Time Name
--------- ---------- ----- ----
25 2021-10-29 14:22 pet/cat
21 2021-10-29 14:22 pet
30 2021-10-29 14:22 pet/cat/fish
0 2021-10-29 14:22 pet/cat/fish/
26 2021-10-29 14:22 pet/cat
22 2021-10-29 14:22 pet
31 2021-10-29 14:22 pet/cat/fish
--------- -------
155 7 files
$ mount-zip file-dir-same-name.zip mnt
$ tree -F mnt
mnt
├── pet/
│ ├── cat/
│ │ ├── fish/
│ │ ├── fish (1)
│ │ └── fish (2)
│ ├── cat (1)
│ └── cat (2)
├── pet (1)
└── pet (2)
3 directories, 6 files
Directories are never renamed. If a file is colliding with a directory, the file will be the one getting renamed.
mount-zip supports encrypted ZIP archives. It understands the legacy ZIP encryption scheme, as well as the more recent AES encryption schemes (AES-128, AES-192 and AES-256).
When mount-zip finds an encrypted file while mounting a ZIP archive, it asks for a password. If the given password does not decrypt the file, then mount-zip refuses to mount the ZIP archive and returns an error:
$ unzip -l different-encryptions.zip
Archive: different-encryptions.zip
Length Date Time Name
--------- ---------- ----- ----
23 2020-08-28 15:22 ClearText.txt
32 2020-08-28 15:23 Encrypted AES-128.txt
32 2020-08-28 15:23 Encrypted AES-192.txt
32 2020-08-28 15:23 Encrypted AES-256.txt
34 2020-08-28 15:23 Encrypted ZipCrypto.txt
--------- -------
153 5 files
$ mount-zip different-encryptions.zip mnt
Need password for File [1] '/Encrypted AES-128.txt'
Password > Got it!
Use the -o force option to mount an encrypted ZIP with a wrong password
Cannot open File [1] '/Encrypted AES-128.txt': Wrong password provided
Providing the correct password allows mount-zip to mount the ZIP archive and decode the files:
$ mount-zip different-encryptions.zip mnt
Need password for File [1] '/Encrypted AES-128.txt'
Password > Got it!
Password is Ok
$ tree mnt
mnt
├── ClearText.txt
├── Encrypted AES-128.txt
├── Encrypted AES-192.txt
├── Encrypted AES-256.txt
└── Encrypted ZipCrypto.txt
0 directories, 5 files
$ md5sum mnt/*
7a542815e2c51837b3d8a8b2ebf36490 mnt/ClearText.txt
07c4edd2a55c9d5614457a21fb40aa56 mnt/Encrypted AES-128.txt
e48d57930ef96ff2ad45867202d3250d mnt/Encrypted AES-192.txt
ca5e064a0835d186f2f6326f88a7078f mnt/Encrypted AES-256.txt
275e8c5aed7e7ce2f32dd1e5e9ee4a5b mnt/Encrypted ZipCrypto.txt
$ cat mnt/*
This is not encrypted.
This is encrypted with AES-128.
This is encrypted with AES-192.
This is encrypted with AES-256.
This is encrypted with ZipCrypto.
You can force mount-zip to mount an encrypted ZIP even without providing the
right password by using the -o force option:
$ mount-zip -o force different-encryptions.zip mnt
Need password for File [1] '/Encrypted AES-128.txt'
Password > Got it!
Continuing despite wrong password because of -o force option
In this case, the files can be listed, but trying to open an encrypted file for which the given password doesn't work results in an I/O error:
$ tree mnt
mnt
├── ClearText.txt
├── Encrypted AES-128.txt
├── Encrypted AES-192.txt
├── Encrypted AES-256.txt
└── Encrypted ZipCrypto.txt
0 directories, 5 files
$ md5sum mnt/*
7a542815e2c51837b3d8a8b2ebf36490 mnt/ClearText.txt
md5sum: 'mnt/Encrypted AES-128.txt': Input/Output error
md5sum: 'mnt/Encrypted AES-192.txt': Input/Output error
md5sum: 'mnt/Encrypted AES-256.txt': Input/Output error
md5sum: 'mnt/Encrypted ZipCrypto.txt': Input/Output error
$ cat mnt/*
This is not encrypted.
cat: 'mnt/Encrypted AES-128.txt': Input/Output error
cat: 'mnt/Encrypted AES-192.txt': Input/Output error
cat: 'mnt/Encrypted AES-256.txt': Input/Output error
cat: 'mnt/Encrypted ZipCrypto.txt': Input/Output error
For security reasons, mount-zip doesn't allow the password to be specified on the command line. However, it is possible to pipe the password to mount-zip's standard input:
$ echo password | mount-zip different-encryptions.zip mnt
Need password for File [1] '/Encrypted AES-128.txt'
Password is Ok
mount-zip shows symbolic links recorded in the ZIP archive:
$ mount-zip symlink.zip mnt
$ tree mnt
mnt
├── date
└── symlink -> ../tmp/date
Note that symbolic links can refer to files located outside the mounted ZIP archive. In some circumstances, these links could pose a security risk.
Symbolic links can be suppressed with the -o nosymlinks option:
$ mount-zip -o nosymlinks symlink.zip mnt
Skipped Symlink [1] '/symlink'
2021-10-28 20:05:01 laptop ~/mount-zip/tests/blackbox/data (intrusive)
$ tree mnt
mnt
└── date
0 directories, 1 file
mount-zip shows special files (sockets, FIFOs or pipes, character and block devices) recorded in the ZIP archive:
$ mount-zip -o default_permissions pkware-specials.zip mnt
$ ls -n mnt
brw-rw---- 1 0 6 8, 1 Aug 3 2019 block
crw--w---- 1 0 5 4, 0 Aug 3 2019 char
prw-r--r-- 1 1000 1000 0 Aug 15 2019 fifo
-rw-r--r-- 3 1000 1000 32 Aug 9 2019 regular
srw------- 1 1000 1000 0 Aug 3 2019 socket
lrwxrwxrwx 1 1000 1000 7 Aug 3 2019 symlink -> regular
lrwxrwxrwx 1 1000 1000 7 Aug 25 2019 symlink2 -> regular
-rw-r--r-- 3 1000 1000 32 Aug 9 2019 z-hardlink1
-rw-r--r-- 3 1000 1000 32 Aug 9 2019 z-hardlink2
brw-rw---- 1 0 6 8, 1 Aug 3 2019 z-hardlink-block
crw--w---- 1 0 5 4, 0 Aug 3 2019 z-hardlink-char
prw-r--r-- 1 1000 1000 0 Aug 15 2019 z-hardlink-fifo
srw------- 1 1000 1000 0 Aug 3 2019 z-hardlink-socket
lrwxrwxrwx 1 1000 1000 7 Aug 3 2019 z-hardlink-symlink -> regular
Special files can be suppressed with the -o nospecials option.
mount-zip shows hard links recorded in the ZIP archive.
In this example, the three file entries 0regular, hlink1 and hlink2 point
to the same inode number (2) and their reference count is 3:
$ mount-zip hlink-chain.zip mnt
$ ls -ni mnt
2 -rw-r--r-- 3 0 0 10 Aug 14 2019 0regular
2 -rw-r--r-- 3 0 0 10 Aug 14 2019 hlink1
2 -rw-r--r-- 3 0 0 10 Aug 14 2019 hlink2
$ md5sum mnt/*
e09c80c42fda55f9d992e59ca6b3307d mnt/0regular
e09c80c42fda55f9d992e59ca6b3307d mnt/hlink1
e09c80c42fda55f9d992e59ca6b3307d mnt/hlink2
Some tools can use the inode number to detect duplicated hard links. In this
example, du only counts the size of the inode (2) once, even though there are
three file entries pointing to it, and only reports 10 bytes instead of 30
bytes:
$ du -b mnt
10 mnt
Duplicated hard links can be suppressed with the -o nohardlinks option.
mount-zip only does the minimum amount of work required to serve the requested data. It offers several caching strategies and storage options to balance performance, mount time, and resource usage.
The following strategies are mutually exclusive. If none is specified, lazy decompression is used by default.
By default, mount-zip only decompresses enough data to serve the reading application. Accessing the beginning of a big compressed file is therefore instantaneous. mount-zip will start caching a file if it detects that this file is getting read in a non-sequential way.
The -o precache option instructs mount-zip to preemptively decompress and
cache the whole ZIP archive(s) at mount time. The cost of decompression is
incurred upfront, ensuring that any subsequent access to the served data is fast
and supports efficient random access.
The -o nocache option disables long-term caching. mount-zip will use a
small rolling buffer in memory to serve data. This minimizes disk and memory
usage but can be significantly slower for non-sequential access patterns or if
the same files are read repeatedly, as data may need to be re-decompressed.
By default, decompressed data is cached in an anonymous temporary file (in
$TMPDIR or /tmp). This cache can use a significant amount of disk space but
is automatically deleted when the ZIP is unmounted. The cache directory can be
changed with the -o cache=DIR option.
The -o memcache option instructs mount-zip to store the cache in RAM
instead of a temporary file. This provides the highest performance but can
consume a large amount of memory. It can be used with both lazy and pre-emptive
caching strategies.
The -o force option allows mount-zip to continue mounting a ZIP archive
even if some errors are encountered. This includes:
- Wrong or missing decryption passwords.
- Unsupported compression or encryption methods.
In these cases, files that cannot be correctly processed will still be listed in the directory tree, but attempting to read them will result in an Input/Output error (EIO).
By default, mount-zip presents all files as being owned by the current user and group, with standard read permissions.
You can explicitly set the user and group of all items in the mounted archive
using the -o uid and -o gid options with the desired numerical IDs.
The -o default_permissions option instructs mount-zip to use the exact
UID, GID, and Unix permission bits stored within the archive for each item. This
includes support for special bits such as SUID, SGID, and SVTX
(sticky bit).
You can apply an octal permission mask to directories (dmask) and files
(fmask). For example, -o fmask=077 would remove all permissions for group
and others from files.
mount-zip works well with large archives containing many files. For example on my laptop, a ZIP archive containing more than 70,000 files is mounted in half a second:
$ ls -lh linux-5.14.15.zip
-rw-r--r-- 1 fdegros primarygroup 231M Oct 28 15:48 linux-5.14.15.zip
$ time mount-zip linux-5.14.15.zip mnt
real 0m0.561s
user 0m0.344s
sys 0m0.212s
$ tree mnt
mnt
└── linux-5.14.15
├── arch
...
4817 directories, 72539 files
$ du -sh mnt
1.1G mnt
The full contents of this mounted ZIP, totaling 1.1 GB, can be extracted with
cp -R in 14 seconds:
$ time cp -R mnt out
real 0m13.810s
user 0m0.605s
sys 0m5.356s
For comparison, unzip extracts the contents of the same ZIP in 8.5 seconds:
$ time unzip -q -d out linux-5.14.15.zip
real 0m8.411s
user 0m6.067s
sys 0m2.270s
Mounting an 8-GB ZIP containing only a few files is instantaneous:
$ ls -lh bru.zip
-rw-r----- 1 fdegros primarygroup 7.9G Sep 2 22:37 bru.zip
$ time mount-zip bru.zip mnt
real 0m0.033s
user 0m0.018s
sys 0m0.011s
$ tree -h mnt
mnt
├── [2.0M] bios
├── [ 25G] disk
└── [ 64M] tools
0 directories, 3 files
Decompressing and reading the 25-GB file from this mounted ZIP takes less than two minutes:
$ dd if=mnt/disk of=/dev/null status=progress
26843545600 bytes (27 GB, 25 GiB) copied, 104.586 s, 257 MB/s
There is no lag when opening and reading the file, and only a moderate amount of
memory is used. The file is getting lazily decompressed by mount-zip as it
is getting read by the dd program.
mount-zip records log messages to the system logger (syslog). These messages can help troubleshoot issues, such as I/O errors or archives that refuse to mount.
To read mount-zip's log messages on most Linux systems:
$ journalctl -t mount-zip
Alternatively, you can run mount-zip in the foreground with the -f
option to see log messages directly on your terminal.
By default, mount-zip writes INFO and ERROR messages. You can
decrease the logging level to just ERROR messages with the -o quiet
option, or increase it to include DEBUG messages with the -o verbose
option.
$ mount-zip -f -o verbose foobar.zip mnt
Indexing 'foobar.zip'...
Allocating 16 buckets
Detected encoding UTF-8 with 15% confidence
Indexed 'foobar.zip' in 0 ms
Mounted 'foobar.zip' on 'mnt' in 2 ms
Reader 1: Opened File [0]
Reader 1: Closed
Unmounting 'foobar.zip' from 'mnt'...
Unmounted 'foobar.zip' in 0 ms
To prevent file names from being recorded in mount-zip's log messages, use
the -o redact option:
$ mount-zip -f -o verbose -o redact bad-crc.zip mnt
Indexing (redacted)...
Allocating 16 buckets
Indexed (redacted) in 0 ms
Mounted (redacted) on (redacted) in 2 ms
Reader 1: Opened File [0]
Cannot read (redacted): Cannot read file: CRC error
Reader 1: Closed
Unmounting (redacted) from (redacted)...
Unmounted (redacted) in 0 ms
mount-zip returns distinct error codes for different error conditions related to the ZIP archives themselves:
0 : Success.
1 : Generic error code for: missing argument, unknown option, unknown file name encoding, mount point cannot be created, mount point is not empty, etc.
11 : An archive is a multipart ZIP.
15 : A ZIP archive cannot be read.
19 : A ZIP archive cannot be found.
21 : A ZIP archive cannot be opened.
23
: Decompression error. This is probably the sign of a wrong password. Use
-o force to bypass the password verification.
26
: Unsupported compression method. Use -o force to bypass the compression
method verification.
29 : An archive is not recognized as a valid ZIP.
31 : A ZIP archive has an inconsistent structure.
34
: Unsupported encryption method. Use -o force to bypass the encryption
method verification.
36
: Password needed. A ZIP archive contains an encrypted file, but no password
was provided. Use -o force to bypass the password verification.
37
: Wrong password. A ZIP archive contains an encrypted file, and the provided
password does not decrypt it. Use -o force to bypass the password
verification.
45 : Possibly truncated or corrupted ZIP archive, as detected by libzip 1.11 or higher.
mount-zip started as a fork of fuse-zip.
The original fuse-zip project was created in 2008 by Alexander Galanin and is available on Bitbucket.
The mount-zip project was then forked from fuse-zip in 2021 and further developed by François Degros. The ability to write and modify ZIP archives has been removed, but a number of optimizations and features have been added:
| Feature | mount-zip | fuse-archive | fuse-zip |
|---|---|---|---|
| Read-Write Mode | ❌ | ❌ | ✅ |
| Read-Only Mode | ✅ | ✅ | ✅ |
| Format Support | ZIP | Wide | ZIP |
| GPG Encryption | ❌ | ✅ | ❌ |
| Native ZIP Encryption | ✅ | ✅ | ✅ |
| Lazy Decompression | ✅ | ✅ | ❌ |
| Default Caching | Lazy | Pre-emptive | N/A |
| Memory Caching | ✅ | ✅ | ✅ |
| Temp File Caching | ✅ | ✅ | ❌ |
| Handles Huge Files | ✅ | ✅ | ❌ |
| Sparse File Detection | ❌ | ✅ | ❌ |
| Precision Timestamps | ✅ | ✅ | ✅ |
| Several Archives | ✅ | ✅ | ❌ |
| Automatic Mount Point | ✅ | ✅ | ❌ |
| FUSE 3 Support | ✅ | ✅ | ❌ |
| Distinct Error Codes | ✅ | ✅ | ❌ |
mount-zip is released under the GNU General Public License Version 3 or later.
fuse-archive(1), fuse-zip(1), fusermount(1), fuse(8), umount(8)