I ran the following command. tar -jcvf ${PWD}.bz2 a b c d. I expected a bz2 folder as the output. But the command did not output anything. what am i missing ?
your command syntax is correct, so if you have permissions for reading a,b,c,d file (or directory???) and write to ./.. directory (one level up), file should be created.
example command output (a,b,d - files, c - directory with 2 files)
a
b
c/
c/file2
c/file1
d
at the end just type:
stat ${PWD}.bz2
Regards,
When you want a output file in a bz2 dir, use ${PWD}/bz2/outputfile
Related
I have a folder /home/user/Document/filepath where I have three files namely file1-1.1.0.txt, file2-1.1.1.txt, file3-1.1.2.txt
and another folder named /home/user/Document/backuppath where I have to move files from /home/user/Document/folderpath which has file1-1.0.0.txt, file2-1.0.1.txt and file3-1.0.2.txt
task is to copy the specific files from folder path to backup path.
To summarize:
the below is the files.txt where I listed the files which has to be copied:
file1-*.txt
file2-*.txt
The below is the move.sh script that execute the movements
for file in `cat files.txt`; do cp "/home/user/Document/folderpath/$file" "/home/user/Documents/backuppath/" ; done
for the above script I am getting the error like
cp: cannot stat '/home/user/Document/folderpath/file1-*.txt': No such file or directory found
cp: cannot stat '/home/user/Document/folderpath/file2-*.txt': No such file or directory found
what I would like to accomplish is that I would like to use the script to copy specific files using * in the place of version numbers., since the version number may vary in the future.
You have wildcard characters in your files.txt. In your cp command, you are using quotes. These quotes prevent the wildcards to be expanded, as you can clearly see from the error message.
One obvious possibility is to not use quotes:
cp /home/user/Document/folderpath/$file /home/user/Documents/backuppath/
Or not use a loop at all:
cp $(<files.txt) /home/user/Documents/backuppath/
However, this would of course break if one line in your files.txt is a filename pattern which contains white spaces. Therefore, I would recommend a second loop over the expanded pattern:
while read file # Puts the next line into 'file'
do
for f in $file # This expands the pattern in 'file'
do
cp "/home/user/Document/folderpath/$f" /home/user/Documents/backuppath
done
done < files.txt
I'm on a Linux system with limited resources and BusyBox -- this version of tar does not support --append, -r. Is there a workaround that will allow me to [1] append files from directory B to an existing tar of files from directory A after [2] making the B-files appear to have come from directory A? (Later, when someone extracts the files, they should all end up in the same directory A.)
Situation: I have a list of files that I want to tar, but I must process some of these files first. The files might be used by other processes so I don't want to edit them in-place. I want to be conservative when using disk space so my script only copies those files which it needs to change (vs copying them all and then processing some and finally archiving them all with tar -- if I copied them all I might run into disk space issues).
This means the files I want to archive end up in two separate locations. But I want the resulting tar file to appear as if they were all in the same location. Near the end of my script, I end up with two text files listing the A and B files by name.
I think this is straightforward with a full-blown version of tar, but I have to work with the BusyBox version (usage below). Thanks in advance for any ideas!
Usage: tar -[cxtzjaZmvO] [-X FILE] [-f TARFILE] [-C DIR] [FILE]...
Create, extract, or list files from a tar file
Operation:
c Create
x Extract
t List
Options:
f Name of TARFILE ('-' for stdin/out)
C Change to DIR before operation
v Verbose
z (De)compress using gzip
j (De)compress using bzip2
a (De)compress using lzma
Z (De)compress using compress
O Extract to stdout
h Follow symlinks
m Don't restore mtime
exclude File to exclude
X File with names to exclude
T File with names to include
In principle, you just need to append a tar repository containing the additional files to the end of the tar file. It is only slightly more difficult than that.
A tar file consists of any number of repetitions of header + file. The header is always a single 512-byte block, and the file is padded to a multiple of 512 bytes, so you can think of these units as being a variable number of 512-byte blocks. Each block is independent; it's header starts with the full pathname to the file. So there is no requirement that files in a directory be tarred together.
There is one complication. At the end of the tar file, there are at least two 512-byte blocks completely filled with 0s. When tar is reading a tar file, it will ignore a single zero-filled header, but the second one will cause it to stop reading the file. If it hits EOF, it will complain, so the terminating empty headers are required.
There might be more than two headers, because tar actually writes in blocks which are a multiple of 512 bytes. Gnu tar, for example, by default writes in multiples of 20 512-byte chunks, so the smallest tar file is normally 10240 bytes.
In order to append new data, you need to first truncate the existing file to eliminate the empty blocks.
I believe that if the tar file was produced by busybox, there will only be two empty blocks, but I haven't inspected the code. That would be easy; you only need to truncate the last 1024 bytes of the file before appending the additional files.
For general tar files, it is trickier. If you knew that the files themselves didn't have NUL bytes in them (i.e. they were all simple text files), you could remove empty headers until you found a block with a non-0 byte in it, which wouldn't be too difficult.
What I would do is:
Truncate the last 1024 bytes of the tar file.
Remember the current size of the tar file.
Append a test tar file consisting of the tar of a file with a simple short message
Verify that tar tf correctly shows the test file
Truncate the file back to the remembered length,
If the tar tf found the test file's name, succeed
If the last 512 bytes of the tar file are all 0s, truncate the last 512 bytes of the file, and return to step 2.
Otherwise fail
If the above procedure succeeds, you can proceed to append the tar repository with the new files.
I don't know if you have a trunc command. If not, you can use dd copy a file over top of an old file at a specified offset (see the seek= option). dd will truncate the file automatically at the end of the copy. You can also use dd to read a 512 byte block (see the skip and count options).
The best solution is to cut the last 1024 bytes and concatenate a new tar after it. In order to append a tar to an existing tar file, they must be uncompressed.
For files like:
$ find a b
a
a/file1
b
b/file2
You can:
$ tar -C a -czvf a.tar.gz .
$ gunzip -c a.tar.gz | { head -c -$((512*2)); tar -C b -c .; } | gzip > a+b.tar.gz
With the result:
$ tar -tzvf a+b.tar.gz
drwxr-xr-x 0/0 0 2018-04-20 16:11:00 ./
-rw-r--r-- 0/0 0 2018-04-20 16:11:00 ./file1
drwxr-xr-x 0/0 0 2018-04-20 16:11:07 ./
-rw-r--r-- 0/0 0 2018-04-20 16:11:07 ./file2
Or you can create both tar in the same command:
$ tar -C a -c . | { head -c -$((512*2)); tar -C b -c .; } | gzip > a+b.tar.gz
Although this is for tar generated by busybox tar. As mentioned in previous answer, GNU tar add multiple of 20 blocks. You need to force the number of blocks to be 1 (--blocking-factor=1) in order to know in advance how many blocks to cut:
$ tar --blocking-factor=1 -C a -c . | { head -c -$((512*2)); tar -C b -c .; } | gzip | tar --blocking-factor=1 -tzv
Anyway, GNU tar do have --append. The last --blocking-factor=1 is only needed if you indent do append the resulting tar again.
So here is what i do already,
i have a abc.txt which contains list of files.Am using abc.txt to
move those files to a folder , tar that folder and finally i download the tar to local pc from server(linux).
it goes like
1.abc.txt
2.abc.txt(files) -> folder
3.Folder -> folder.tar
4.folder.tar -> local pc.
Now i need to change this like below,
if abc.txt contains 2 files namely,
example1.css
example2.css
i need to download those files from abc.txt seperately and directly to local pc ,
since ftp or sftp need the file name to download it how can i read that
from abc.txt.
Please help.
I think the hub of your problem is how to extract the correct files from your list for your subsequent two logic paths.
egrep 'example1.css|example2.css' abc.txt
will give you all lines that match the exceptions, and
egrep -v 'example1.css|example2.css' abc.txt
will give you all lines that don't match the exceptions
I working with linux, bash.
I have one directory with 100 folders in it, each one named different.
In each of these 100 folders, there is a file called first.bars (so I have 100 files named first.bars). Although all named first.bars, the files are actually slightly different.
I want to get all these files moved to one new folder and rename/number these files so that I know which file comes from which folder. So the first first.bars file must be renamed to 001.bars, the second to 002.bars.. etc.
I have tried the following:
ls -d * >> /home/directorywiththe100folders/list.txt
cat list.txt | while read line;
do cd $line;
mv first.bars /home/newfolder
This does not work because I can't have 100 files, named the same, in one folder. So I only need to know how to rename them. The renaming must be connected to the cat list.txt, because the first line is the folder containing the first file wich is moved and renamed. That file will be called 001.bars.
Try doing this :
$ rename 's/^.*?\./sprintf("%03d.", $c++)/e' *.bar
If you want more information about this command, see this recent response I gave earlier : How do I rename multiple files beginning with a Unix timestamp - imapsync issue
If the rename command is not available,
for d in /home/directorywiththe100folders/*/; do
newfile=$(printf "/home/newfolder/%d.bars" $(( c++ )) )
mv "$d/first.bars" "$newfile"
done
I have following architecture of files in a directory.
Directory
/A/abc.xyz
/B/abc.xyz
/C/abc.xyz
/D/abc.xyz
/E/abc.xyz
I want to execute a program on acb.xyz in each SubDirectory. Save Output files in different directory i.e. Directory/processed with the name of SubDirectory appended in the name of output files.
Can it be written in following way? Need corrections.
for i in `ls "Directory/"`
do
program.pl $i/abc.xyz > processed/$i-abc.xyz
done
for dir in Directory/*; do
program.pl "$dir/abc.xyz" > "processed/${dir##*/}-abc.xyz"
done
The ${dir##*/} part strips the leading directory names from $dir, so Directory/A becomes just A. I added quotes to ensure directory names with whitespace don't cause issue (a good habit, even if you know there are no spaces).
As an alternative to the string munging you could simplify this if you first change directory:
cd Directory
for dir in *; do
program.pl "$dir/abc.xyz" > "processed/$dir-abc.xyz"
done