1SQFS2TAR(1)                      User Commands                     SQFS2TAR(1)
2
3
4

NAME

6       sqfs2tar - turn a SquashFS image into a tar archive
7

SYNOPSIS

9       sqfs2tar [OPTIONS...] <sqfsfile>
10

DESCRIPTION

12       Quickly  and painlessly turn a SquashFS filesystem image into a tar ar‐
13       chive that can then be examined and processed by any tool that can work
14       on tar archives. The resulting archive is written to stdout.
15
16       Possible options:
17
18       --compressor, -c <name>
19              By  default  the  result  is a raw, uncompressed tar ball. Using
20              this option it is possible to select a stream compression format
21              (such as gzip, xz, zstd or bzip2) to use for the output archive.
22
23              Run sqfs2tar --help to get a list of all available compressors.
24
25       --root-becomes, -r <dir>
26              Prefix  all  paths  in the tarball with the given directory name
27              and add an entry for this directory that receives all meta  data
28              (permissions,  ownership, extended attributes, et cetera) of the
29              root inode.
30
31              The special value . can be used since many tar  archivers  them‐
32              selves  pack  the  attributes of the root directory that way and
33              naturally support this.
34
35              If this option is not used, all meta data from the root inode IS
36              LOST!
37
38       --subdir, -d <dir>
39              Unpack  the  given sub directory instead of the filesystem root.
40              Can be specified more than once to select multiple  directories.
41              If only one is specified, it becomes the new root of the archive
42              filesystem tree.
43
44       --keep-as-dir, -k
45              If --subdir is used only once, don't make the subdir the archive
46              root,  instead  keep  it as prefix for all unpacked files. Using
47              --subdir more than once implies --keep-as-dir.
48
49       --no-xattr, -X
50              Discard extended attributes from the SquashFS image. The default
51              behavior  is to copy all xattrs attached to SquashFS inodes into
52              the resulting tar archive.
53
54       --no-hard-links, -L
55              Normally, sqfs2tar runs hard link detection and  generates  hard
56              links  for entries that refer to the same inode. If this flag is
57              set, hard link detection is not  performed  and  duplicate  data
58              records are generated instead.
59
60       --no-skip, -s
61              Abort if a file cannot be stored in a tar archive. For instance,
62              the tar format does not support socket files, but SquashFS does.
63              The default behaviour of sqfs2tar is to emit a warning to stderr
64              and skip the entry. If this flag is set, processing  is  aborted
65              and sqfs2tar exits with an error status.
66
67       --help, -h
68              Print help text and exit.
69
70       --version, -V
71              Print version information and exit.
72

COMPATIBILITY

74       The  output format is pre-POSIX ustar using GNU extensions where neces‐
75       sary.  Experimentation determined that this is most widely supported by
76       activeley  used  tar  implementations (besides GNU tar), even more than
77       the newer POSIX format with PAX extensions.
78
79       If any file or directory is encountered that cannot be converted, it is
80       skipped and a warning is written to stderr. Unless the --no-skip option
81       is set, which aborts processing if a file cannot be converted.
82
83       This mainly affects socket files which are supported  by  SquashFS  but
84       not by POSIX tar, GNU tar or PAX.
85
86       Since  the tar format contains a sequence of files with absolute names,
87       it has no direct concept of a tree or  an  unnamed  root  node.  Conse‐
88       quently,  meta  data  from  the SquashFS root inode is lost, unless the
89       --root-becomes option is used.
90
91       The output archive can optionally be compressed. Default  settings  are
92       used  for the supported compressors and there is currently no intention
93       to expose finer grained control over them.  To  set  custom  compressor
94       flags, create an uncompressed archive and pipe it into a dedicated com‐
95       pressor process.
96
97

EXAMPLES

99       Turn a SquashFS image into a tar archive:
100
101              sqfs2tar rootfs.sqfs > rootfs.tar
102
103       Creating a compressed archive with gzip headers:
104
105              sqfs2tar --compressor gzip rootfs.sqfs > rootfs.tar.gz
106
107       Compressing the output archive, but using custom compressor flags:
108
109              sqfs2tar rootfs.sqfs | xz -9e > rootfs.tar.xz
110

SEE ALSO

112       rdsquashfs(1), tar2sqfs(1)
113

AUTHOR

115       Written by David Oberhollenzer.
116

118       Copyright © 2019 David Oberhollenzer License GPLv3+: GNU GPL version  3
119       or later <https://gnu.org/licenses/gpl.html>.
120       This  is  free  software:  you  are free to change and redistribute it.
121       There is NO WARRANTY, to the extent permitted by law.
122
123
124
125sqfs2tar                           June 2019                       SQFS2TAR(1)
Impressum