WRAP(8) WRAP(8)
NAME
wrap, create, info, inst, wdiff - software package
preparation
SYNOPSIS
wrap/create [ -luv ] [ -d desc ] [ -p proto ] [ -r root ] [
-t time ] name [ prefix... ]
wrap/inst [ -ovxF ] [ -r root ] file [ prefix... ]
wrap/info [ -r root ] file
wrap/wdiff [ -blp ] [ -r root ] file [ prefix... ]
DESCRIPTION
These programs are used to manage software packages.
Packages are identified by a unique name, and should corre-
spond to some reference tree. For example, the base Plan 9
installation package is named plan9 and corresponds to the
root of the Plan 9 distribution file server at Bell Labs.
Successive versions are distinguished by a date stored as
seconds since January 1, 1970.
A base package contains all files in the reference tree at
some time. Wrap/create creates these by default.
An update is a package listing only files modified relative
to some earlier tree. The time of the prerequisite tree is
included in the update. The target tree's time is the time
of the base package or the time of the last installed
update. The update cannot be installed unless the target
tree is dated at or after the prerequisite time.
Wrap/create -u creates updates when no prefix is given.
A partial update is like an update but usually only contains
a few subtrees. For example, one might create a partial
update of the Plan 9 distribution package containing only
changes to acme. Installing a partial update does not change
the target tree's time. Wrap/create -u creates partial
updates when one or more prefixes are given.
Wrap/inst installs base packages, updates, and partial
updates, taking into account version conflicts, prerequi-
sites, and the possibility of local modifications.
Wrap/info prints information about a package or update, and
wrap/wdiff runs diff to compare files in a package archive
with installed files. Wdiff -l merely lists those files
modified or removed since the package or update was created,
and can be used on an installed tree instead of a package
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file. When used with an installed tree, only files modified
or removed since the most recent updates are listed; wdiff
-p shows changes since the last full package.
To decide whether a given update contains files fresher than
those currently installed on the system, it is not enough to
compare the update's date with the date of the most recent
update to the same package: updates may only involve parts
of a package, so updates can only be partially ordered. As
an example, if you have a full Plan 9 distribution package
and two updates, one to acme and one to aux/vga, it is not
correct to require one to be installed before the other, or
to prohibit one from being installed once the other has
been. To handle such cases, date comparisons must made on a
per-file basis rather than a per-update basis.
To do this, create includes in each package and update a
list /wrap/name/time/md5sum of the contained files along
with their MD5 checksums. A file in an update will be writ-
ten over an installed file only if the installed file is
from an update older than the one currently under considera-
tion; otherwise a warning will be printed. If the currently
installed file does not have the expected checksum, that
usually indicates the presence of local modifications. In
such cases, the file is not overwritten and a warning is
printed. This behavior can be overriden, as described
below.
Create writes to standard output a package with name name
and time stamp time (by default, the current time), contain-
ing the files named by proto (see proto(2)). In addition to
the named files, a package may contain a one-line file
describing its contents; the file contains desc, when speci-
fied. If no proto is specified,
/sys/lib/sysconfig/proto/allproto is used.
If create is given the -u flag, it compares the files con-
tained in the named package (which may be a file or the name
of a package installed in the root; see below) with those
currently in the file system, and writes an update archive
that only contains modified files. If no proto is given, it
uses the proto used to make the archive being updated. If
any prefix es are specified, the update is restricted to
just those changes that concern files having names with any
of the prefix es as a prefix. Without the -u flag, prefixes
are not allowed. If create is given the -u flag it creates
an update package. If prefixes are specified, create cre-
ates a partial update.
The -l flag to create causes it to write a list of the files
it would have included in an archive, rather than preparing
the archive itself.
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Inst unpacks a package or update created by create. It
extracts from the package or update the files with names
starting with prefixes (default all files) and installs them
in the tree rooted at root (default /). Inst attempts to
set the modes on the extracted files to those in the
archive. If the -o flag is given, install will attempt to
set the owner and group as well; this is only possible if
the allow command has been typed at the file server (see
fs(8) or kfscmd(8)). The -x flag causes inst to print what
actions it would do to install the package, but not actually
perform them. As described above, inst performs a number of
checks to avoid overwriting new files with old ones; these
checks are disabled by the -F flag.
EXAMPLES
Create a package consisting of the entire Plan 9 distribu-
tion tree:
wrap/create -r /plan9dist -d 'Plan 9 — Third Edition' \
-p plan9proto plan9 | gzip > plan9.9gz
Create a base package as well as a full update. Note that
we need to use the -t flag to make sure both have the same
timestamp.
now=`{date -n}
wrap/create -r /plan9dist -d 'Plan 9 — Third Edition' \
-p plan9proto -t $now plan9 | gzip > plan9.9gz
wrap/create -ur /plan9dist -t $now oldplan9.9gz |
gzip > update.9gz
Create a partial update containing new VGA software:
wrap/create -ur /plan9dist plan9.9gz `{cat /tmp/vgafiles} |
gzip >vga.9gz
where /tmp/vgafiles is a text file containing:
/386/bin/aux/vga
/lib/vgadb
/sys/src/cmd/aux/vga
/sys/src/9/pc/devvga.c
/sys/src/9/pc/vga
Note that since the strings are just prefixes, the last line
will match files such as /sys/src/9/pc/vgamach64xx.c and
/sys/src/9/pc/vga.h.
Install the VGA update on a kfs(4) file system.
disk/kfscmd allow
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mount /srv/kfs /n/kfs
wrap/inst -or /n/kfs vga.9gz
disk/kfscmd disallow
Suppose that the update contains a new /386/bin/aux/vga and
/lib/vgadb but those files have been changed since they were
installed. Install will produce the following messages:
skipping /386/bin/aux/vga
skipping /lib/vgadb: locally updated
wrap/wdiff vga.9gz \
/386/bin/aux/vga \
/lib/vgadb
The printed command can be executed to inspect the differ-
ences and decide which files to overwrite with ones from the
package; to actually overwrite the files, change wdiff to
inst -F and send the command again.
Wrap an installed package quux for redistribution as a stan-
dalone package:
wrap/create -d 'Repackaged quux' -r /root \
-p /root/wrap/quux/time/proto quux | gzip > newquux.9gz
To view and then package just your changes:
wrap/wdiff -lr /root quux
wrap/wdiff -r /root quux.9gz
wrap/create -u -r /root quux >quuxpatch.9gz
Note that wrap/wdiff -l does not require the original
archive: it can use checksums to determine which files have
changed. By default (without -l) an archive is required for
access to the original files.
FILES
Installed package information is maintained via a small tree
rooted at dst/wrap. For each package and update, there is a
directory name/time that contains the following files:
desc The description for the package, if any.
md5sum
A sorted list of all files in the package, along with
their MD5 checksums.
package
An empty file, if this is a package.
proto
The proto file used to create this package.
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remove
For an update, the list of obsolete files that should
be removed.
update
If this is an update, contains the decimal date of the
package being updated.
done The installation of the package completed successfully.
Update packages contain both package and update files. A
package is itself an (optionally gzipped) mkfs-style archive
that contains /wrap/name and /wrap/name/time as the only
directories under /wrap. The entries must be the first ones
in the archive to allow for quick access in compressed
archives.
SOURCE
/sys/src/cmd/wrap
SEE ALSO
diff(1), md5sum (in sum(1)), tar(1), proto(2), archfs(4),
mkfs(8)
BUGS
Because inst sets the modes on the created files, permission
checking must be turned off on the file server in order to
create files in unwritable directories or to overwrite
updated files that are not normally writable.
In the absence of the -l flag (which can use the MD5 check-
sums alone) wrap/wdiff must uncompress the entire archive to
pass it to archfs(4).
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