Very Computer

I've been trying to compress a large directory structure using gzip, and
have tried the following commands:

gzip -r directory_name > zipped_file.gz
gzip -rc directory_name > zipped_file.gz

Neither one of these seems to work. I believe the problem is that there are
symbolic links within the directory tree that I am trying to compress that
link to other directories in the same tree. The program seems to get stuck
with this. Is there a flag for gzip that makes it ignore symbolic links? If
not, how else would I zip a directory tree like this.

Thanks in advance for the help,
Adam

Quote:> Neither one of these seems to work. I believe the problem is that there are

---
"... What with you being his parents and all, I think that you could
be trusted not to shaft him."  -- Robert Chang, rec.games.board

   Gzip will only attempt to compress regular files. In particular,
   it will ignore symbolic links.

Also, the resursive option of gzip does not create a single zip file
that contains the entire directory tree. Rather, it compresses each
file in the directory tree, like so:

  $ ls -l foo
  total 135
  -rw-r--r--  1 bozo clowns  53660 Feb 10 23:24 bar
  -rw-r--r--  1 bozo clowns  83089 Feb 10 23:24 baz
  $ gzip -r foo
  $ ls -l foo
  total 121
  -rw-r--r--  1 bozo clowns  47272 Feb 10 23:24 bar.gz
  -rw-r--r--  1 bozo clowns  75610 Feb 10 23:24 baz.gz
  $

Is that what you want? Maybe what you really want is something
like this:

$ tar cf - foo | gzip > foo.tar.gz

tar collects the directory tree into a single tar-format stream that
is written to stdout and then passed through gzip to the file named
foo.tar.gz. Is that what you want?

--

Second, gzip does not write to stdout by default, so

gzip -r directory_name > zipped_file.gz

does absolutely nothing.  If you want to write to stdout, you want "gzip -c"

Third, gzip -r individually zips every file it acts on into its own .gz

$ mkdir /test
$ cd /test
$ touch a b c d
$ ls
 a b c d
$ gzip -r /test
$ ls
 a.gz b.gz c.gz d.gz

I don't know if this is the behavior you want...  If you want one big .gz file
with everything in it, either cat the files together first:

$ cat a b c d | gzip -c > bigfile.gz

Or, (this is way better), use tar to collect all your files and directory
structure, uncompressed, into a single .tar file.  Then you gzip that.  This
is what is known as a tarball, and is a typical method of distributing unix
software.

Here we go:

$ tar -cf - (directory to compress) | gzip -f  > (filename.tar.gz)

Oh, and btw, tar also ignores symlinks, so no worries there.

Hope this helps,
Ryan.

Quote:>I've been trying to compress a large directory structure using gzip, and
>have tried the following commands:

>gzip -r directory_name > zipped_file.gz
>gzip -rc directory_name > zipped_file.gz

zip combines archiving and compression.  gzip only compresses.  so, if you
want archiving and compression you can use gzip along with an archival
tool, e.g., cpio or tar.

the following are equivalent, each directory and file in `directory_name'
or below is copied into an archive, and the archive features compression so
that it is (probably) smaller than the sum of the file sizes.  however, the
archives are completely different, and cannot (generally) be interchanged,
but their purpose and abilities are the same.

  zip -r zipped_file.zip directory_name

  tar -cpvf - directory_name | gzip > gzipped_file.tar.gz

  find directory_name | cpio -ov | gzip > gzipped_file.cpio.gz

a quick example ...

| $ mkdir foo
| $ touch foo/a
| $ touch foo/b
| $ mkdir foo/c
| $ touch foo/c/d
| $ touch foo/c/e
| $ zip -r foo.zip foo
|   adding: foo/ (stored 0%)
|   adding: foo/a (stored 0%)
|   adding: foo/b (stored 0%)
|   adding: foo/c/ (stored 0%)
|   adding: foo/c/d (stored 0%)
|   adding: foo/c/e (stored 0%)
| $ tar -cpvf - foo | gzip >foo.tar.gz
| foo/
| foo/a
| foo/b
| foo/c/
| foo/c/d
| foo/c/e
| $ find foo | cpio -ov | gzip > foo.cpio.gz
| foo
| foo/a
| foo/b
| foo/c
| foo/c/d
| foo/c/e
| 1 block
| $ unzip -v foo.zip
| Archive:  foo.zip
|  Length   Method    Size  Ratio   Date   Time   CRC-32    Name
| --------  ------  ------- -----   ----   ----   ------    ----
|        0  Stored        0   0%  09-20-01 14:56  00000000  foo/
|        0  Stored        0   0%  09-20-01 14:56  00000000  foo/a
|        0  Stored        0   0%  09-20-01 14:56  00000000  foo/b
|        0  Stored        0   0%  09-20-01 14:56  00000000  foo/c/
|        0  Stored        0   0%  09-20-01 14:56  00000000  foo/c/d
|        0  Stored        0   0%  09-20-01 14:56  00000000  foo/c/e
| --------          -------  ---                            -------
|        0                0   0%                            6 files
| $ gunzip -c foo.tar.gz | tar -tvf -
| drwx------ twkmhnno/twkmhnno 0 2001-09-20 14:56:19 foo/
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:15 foo/a
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:17 foo/b
| drwx------ twkmhnno/twkmhnno 0 2001-09-20 14:56:27 foo/c/
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:26 foo/c/d
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:27 foo/c/e
| $ gunzip -c foo.cpio.gz | cpio -itv
| drwx------ twkmhnno/twkmhnno 0 2001-09-20 14:56:19 foo
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:15 foo/a
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:17 foo/b
| drwx------ twkmhnno/twkmhnno 0 2001-09-20 14:56:27 foo/c
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:26 foo/c/d
| -rw------- twkmhnno/twkmhnno 0 2001-09-20 14:56:27 foo/c/e
| 1 block

another example showing compression (using the contents of my $TMPDIR) but
with verbosity turned down ...

| $ du -s tmp
| 2016    tmp
| $ find tmp | wc -l
|     219
| $ zip -qr foo.zip tmp
| $ tar -cpf - tmp | gzip > foo.tar.gz
| $ find tmp | cpio -o | gzip > foo.cpio.gz
| 3742 blocks
| $ ls -s foo.*
| 1137 foo.cpio.gz
| 1141 foo.tar.gz
| 1224 foo.zip

--
okay, have a sig then

Adam

Quote:> Hello,

> I've been trying to compress a large directory structure using gzip, and
> have tried the following commands:

> gzip -r directory_name > zipped_file.gz
> gzip -rc directory_name > zipped_file.gz

> Neither one of these seems to work. I believe the problem is that there
are
> symbolic links within the directory tree that I am trying to compress that
> link to other directories in the same tree. The program seems to get stuck
> with this. Is there a flag for gzip that makes it ignore symbolic links?
If
> not, how else would I zip a directory tree like this.

> Thanks in advance for the help,
> Adam

Come to think of it, I do have one other question. After I tar-ed the
directory, including all of the files and directories beneath it, I
transported the tar-ed file to a Windows based machine for the purpose of
backing up the data. Then, I used WinZip to extract all of the data into its
original directory structure. However, some files seemed not to know what
directory they belonged in and were just placed in the base directory. Why
does this happen? ...only to some files? Is that a limitation of tar, that
sometimes with larges jobs it produces errors lik that? My largest directory
that I tar-ed was about 1GB. The command line I used to tar the files
together was:

tar -cvf dir_name.tar dir_name        (from within the directory dir_name)

Anyways, thanks again for the help.

Adam

Quote:> Hello,

> I've been trying to compress a large directory structure using gzip, and
> have tried the following commands:

> gzip -r directory_name > zipped_file.gz
> gzip -rc directory_name > zipped_file.gz

> Neither one of these seems to work. I believe the problem is that there
are
> symbolic links within the directory tree that I am trying to compress that
> link to other directories in the same tree. The program seems to get stuck
> with this. Is there a flag for gzip that makes it ignore symbolic links?
If
> not, how else would I zip a directory tree like this.

> Thanks in advance for the help,
> Adam

Quote:>some files seemed not to know what
>directory they belonged in and were just placed in the base directory. Why
>does this happen? ...only to some files?

inspect the output of ``tar tvf dir_name.tar''.

Quote:>tar -cvf dir_name.tar dir_name        (from within the directory dir_name)

--
okay, have a sig then