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Diffstat (limited to 'doc/tar2sqfs.1')
| -rw-r--r-- | doc/tar2sqfs.1 | 42 |
1 files changed, 23 insertions, 19 deletions
diff --git a/doc/tar2sqfs.1 b/doc/tar2sqfs.1 index 346d7e7..c2c7f72 100644 --- a/doc/tar2sqfs.1 +++ b/doc/tar2sqfs.1 @@ -1,16 +1,16 @@ .TH TAR2SQFS "1" "June 2019" "tar2sqfs" "User Commands" .SH NAME -tar2sqfs \- create a squashfs image from a tar archive +tar2sqfs \- create a SquashFS image from a tar archive .SH SYNOPSIS .B tar2sqfs [\fI\,OPTIONS\/\fR...] \fI\,<sqfsfile>\/\fR .SH DESCRIPTION -Read an uncompressed tar archive from stdin and turn it into a squashfs +Read an uncompressed tar archive from stdin and turn it into a SquashFS filesystem image. -The idea is to quickly and painlessly turn a tar ball into a squashfs +The idea is to quickly and painlessly turn a tar ball into a SquashFS filesystem image, so existing tools that work with tar can be used for -squashfs. +SquashFS. .PP Possible options: .TP @@ -34,18 +34,13 @@ starts waiting for the block processors to catch up. Higher values result in higher memory consumption. Defaults to 10 times the number of workers. .TP \fB\-\-block\-size\fR, \fB\-b\fR <size> -Block size to use for Squashfs image. +Block size to use for SquashFS image. Defaults to 131072. .TP \fB\-\-dev\-block\-size\fR, \fB\-B\fR <size> Device block size to padd the image to. Defaults to 4096. .TP -\fB\-\-keep\-time\fR, \fB\-k\fR -Keep the same time stamps stored in the tar archive for the SquashFS instead of -setting defaults on all files. The root inode and the modification time on the -SquashFS image itself will still be set to defaults. -.TP \fB\-\-defaults\fR, \fB\-d\fR <options> A comma seperated list of default values for implicitly created directories. @@ -66,6 +61,16 @@ mtime=<value>;\fB$SOURCE\_DATE\_EPOCH\fR if set, 0 otherwise .TE .TP .TP +\fB\-\-no\-keep\-time\fR, \fB\-k\fR +Replace the time stamps from the tar archive with default time stamps for all +entries. + +The default behavior if not specified, is to preserve the time stamps from the +archive to the extent possible (SquashFS has second resolution and 32 bit time +stamps; tar can use extensions to specify much larger timestamps with arbitrary +precision). The root inode and the modification time on the SquashFS image +itself will always still be set to defaults. +.TP \fB\-\-no\-xattr\fR, \fB\-x\fR Do not copy extended attributes from archive. Default behaviour is to copy all extended attributes and skip the ones that cannot be encoded in SquashFS. @@ -88,15 +93,14 @@ Print help text and exit. \fB\-\-version\fR, \fB\-V\fR Print version information and exit. .SH COMPATIBILITY -The tool is designed to support a broad variety of commonly used tar archives. -Currently the tool can process v7 format, pre-POSIX ustar, POSIX tar and GNU -tar archives. PAX extension headers are supported. +Currently the program can process v7 format, pre-POSIX ustar, POSIX tar and GNU +tar archives. PAX extension headers are also supported. -The support for GNU tar is limited to commonly used header formats (i.e. some -older, legacy headers are not supported) and extensions like sparse files. +The support for GNU tar is limited to commonly used subset (i.e. some legacy +extensions that GNU tar itself no longer generates are not supported; neither +are mutli volume archives). Hard links are currently not supported and silently converted to symlinks. -Furthermore, none of the various xattr extensions are currently implemented. Extended attributes are supported through the SCHILY.xattr PAX extension (favoured by GNU tar and star) or through the LIBARCHIVE.xattr PAX extension. @@ -118,15 +122,15 @@ are set. Explicit command line switches are always preferred over the environment variables. .SH EXAMPLES .TP -Turn an uncompressed tar archive into a squashfs image: +Turn an uncompressed tar archive into a SquashFS image: .IP tar2sqfs rootfs.sqfs < rootfs.tar .TP -Turn a gzip'ed tar archive into a squashfs image: +Turn a gzip'ed tar archive into a SquashFS image: .IP zcat rootfs.tar.gz | tar2sqfs rootfs.sqfs .TP -Turn an LZMA2 compressed tar archive into a squashfs image: +Turn an LZMA2 compressed tar archive into a SquashFS image: .IP xzcat rootfs.tar.xz | tar2sqfs rootfs.sqfs .SH SEE ALSO |