I can't think of other way to run a command line that outputs binary files, so I'll have to go with this.
Let's add a binary file to a git repository
mkdir test
cd test
git init .
wget https://upload.wikimedia.org/wikipedia/commons/thumb/8/85/Camelia.svg/320px-Camelia.svg.png
git add 320px-Camelia.svg.png
git commit -am "Added Camelia"
Grab the commit hash that that outputs, we'll use it as <grabbed hash> below.
Now, run this:
say (run "git", "show", "<grabbed hash>:Camelia.svg.png", :out).out
This will return a Malformed UTF-8 message. Fair enough, it's not binary. However, I have tried to capture that exception with try and there's no way. I've tried to separate the run from the out, I still get an exception that can't be captured. Any idea?
Pass the :bin option to run in order to have it do binary I/O instead. Example using curl:
$ raku -e 'say (run "curl", "--no-progress-meter", "https://raku.org/camelia-logo.png", :out, :bin).out.slurp'
Buf[uint8]:0x<89 50 4E 47 0D 0A 1A 0A 00 00 00 0D 49 48 44 52 00 00 01 05 00 00 00 F3 08 06 00 00 00 8F 2A 03 21 00 00 00 01 73 52 47 42 00 AE CE 1C E9 00 00 00 09 70 48 59 73 00 00 0F 61 00 00 0F 61 01 A8 3F A7 69 00 00 00 07 74 49 4D 45 07 D9 07 11 03 07 3A 28 6B FA 81 00 00 00 1A 74 45 58 74 43 6F 6D 6D 65 6E ...>
Related
I'm trying to store a Buffer into a bytea type column. I'm using a Postgres database and I have successfully connected to this database with node-postgres. I am able to update any other field, but I just can't find out what the syntax is to properly store a Buffer.
At the moment, there are already images in that database, that were written with a different system and language. I am not able to to re-use this system to achieve what we need.
The output of those existing images is also a Buffer:
<Buffer 89 50 4e 47 0d 0a 1a 0a 00 00 00 0d 49 48 44 52 00 00 04 38 00 00 04 38 08 06 00 00 00 ec 10 6c 8f 00 00 00 04 73 42 49 54 08 08 08 08 7c 08 64 88 00 ... 13315 more bytes>
And I have prepared the an image that should overwrite this value:
<Buffer 75 ab 5a 8a 66 a0 7b fa 67 81 b6 ac 7b ae 22 54 13 91 c3 42 86 82 80 00 00 03 52 52 11 14 80 00 00 2a 00 00 00 2a 02 00 00 00 00 14 48 3e 9a 00 00 00 ... 3153 more bytes>.
All good, so far.
I now need to use the proper SQL UPDATE statement, but I have not been able to figure that out. I have found some answers suggesting converting it using .toString('hex') and prepending it with \\x, but this does not result in the same value format.
My update statement now looks something like this (where imageData is the second Buffer example above):
await pool.query(
`UPDATE image
SET data = '${imageData}'::bytea
WHERE id = '00413567-fdd7-4765-be30-7f80c2d8ce57'`
)
Some requirements:
I can not use an external file
I can not use a different value format
I can not use a different tech stack
Background is that I have a log file that contains hex dumps that I want to convert with xxd to get that nice ASCII column that shows possible strings in the binary data.
The log file format looks like this:
My interesting hex dump:
00 53 00 6f 00 6d 00 65 00 20 00 74 00 65 00 78
00 74 00 20 00 65 00 78 00 61 00 6d 00 70 00 6c
00 65 00 20 00 75 00 73 00 69 00 6e 00 67 00 20
00 55 00 54 00 46 00 2d 00 31 00 36 00 20 00 69
00 6e 00 20 00 6f 00 72 00 64 00 65 00 72 00 20
00 74 00 6f 00 20 00 67 00 65 00 74 00 20 00 30
00 78 00 30 00 30 00 20 00 62 00 79 00 74 00 65
00 73 00 2e
Visually selecting the hex dump and do xxd -r -p followed by a xxd -g1 on the result does exactly what I'm aiming for.
However, since the number of dumps I want to convert are quite a few I would rather automate the process.
So I'm using the following substitute command to do the conversion:
:%s/\(\x\{2\} \?\)\{16\}\_.*/\=system('xxd -g1',system('xxd -r -p',submatch(0)))
The expression matches the entire hex dump in the log file. The match is sent to xxd -r -p as stdin and its output is used as stdin for xxd -g1.
Well, that's the idea at least.
The thing is that the above almost works. It produces the following result:
My interesting hex dump:
00000000: 01 53 01 6f 01 6d 01 65 01 20 01 74 01 65 01 78 .S.o.m.e. .t.e.x
00000010: 01 74 01 20 01 65 01 78 01 61 01 6d 01 70 01 6c .t. .e.x.a.m.p.l
00000020: 01 65 01 20 01 75 01 73 01 69 01 6e 01 67 01 20 .e. .u.s.i.n.g.
00000030: 01 55 01 54 01 46 01 2d 01 31 01 36 01 20 01 69 .U.T.F.-.1.6. .i
00000040: 01 6e 01 20 01 6f 01 72 01 64 01 65 01 72 01 20 .n. .o.r.d.e.r.
00000050: 01 74 01 6f 01 20 01 67 01 65 01 74 01 20 01 30 .t.o. .g.e.t. .0
00000060: 01 78 01 30 01 30 01 20 01 62 01 79 01 74 01 65 .x.0.0. .b.y.t.e
00000070: 01 73 01 2e .s..
All 00 bytes have mysteriously transformed into 01.
It should have produced the following:
My interesting hex dump:
00000000: 00 53 00 6f 00 6d 00 65 00 20 00 74 00 65 00 78 .S.o.m.e. .t.e.x
00000010: 00 74 00 20 00 65 00 78 00 61 00 6d 00 70 00 6c .t. .e.x.a.m.p.l
00000020: 00 65 00 20 00 75 00 73 00 69 00 6e 00 67 00 20 .e. .u.s.i.n.g.
00000030: 00 55 00 54 00 46 00 2d 00 31 00 36 00 20 00 69 .U.T.F.-.1.6. .i
00000040: 00 6e 00 20 00 6f 00 72 00 64 00 65 00 72 00 20 .n. .o.r.d.e.r.
00000050: 00 74 00 6f 00 20 00 67 00 65 00 74 00 20 00 30 .t.o. .g.e.t. .0
00000060: 00 78 00 30 00 30 00 20 00 62 00 79 00 74 00 65 .x.0.0. .b.y.t.e
00000070: 00 73 00 2e .s..
What am I not getting here?
Of course I can use macros and other ways of doing this, but I want to understand why my substitution command doesn't do what I expect.
Edit:
For anyone that want to achieve the same thing I provide the substitution expression that works on an entire file. The expression above was only for testing purposes using the log file example also from above.
The one below is the one that performs a correct conversion, modified based on the information Kent provided in his answer.
:%s/\(\(\x\{2\} \)\{16\}\_.\)\+/\=system('xxd -p -r | xxd -g1',submatch(0))
very likely, the problem is string conversion in the system() The input will be converted into a string by vim, so does the output of your first xxd command.
You can try to extract that hex parts into a file. then:
xxd -r -p theFile|vim -
And then calling the system('xxd -g1', alltext), you are gonna get something else than 00 too.
This doesn't work in the same way of a pipe (xxd ...|xxd...). But unfortunately, the system() function doesn't accept pipes.
If you want to fix your :s command, you need to call systemlist() on your first xxd call to get the data in binary format, then pass it to the 2nd xxd:
:%s/\(\x\{2\} \?\)\{16\}\_.*/\=system('xxd -g1',systemlist('xxd -r -p',submatch(0)))
The cmd above will generate the 00s. since there is no string conversion.
However, when working with some data format other than plain string, perhaps we can use filters instead of calling system(). It would be a lot eaiser. For your example:
2,$!xxd -r -p|xxd -g1
I would like to know to recover deleted file from FAT. I created fat.img as below.
cd /tmp
dd if=/dev/zero of=fat.img bs=1024 count=100
mkfs.msdos fat.img
mkdir -p /tmp/fs
sudo mount -t msdos fat.img /tmp/fs -o umask=000,loop
Now i am creating file with some text.
cd/tmp/fs
echo "hello world"> name
Using hexdump to see how it was saved
cd ..
hexdump -C fat.img
00000000 eb 3c 90 6d 6b 66 73 2e 66 61 74 00 02 04 01 00 |.<.mkfs.fat.....|
00000010 02 00 02 c8 00 f8 01 00 20 00 40 00 00 00 00 00 |........ .#.....|
00000020 00 00 00 00 80 01 29 3c 69 e6 fb 4e 4f 20 4e 41 |......)<i..NO NA|
00000030 4d 45 20 20 20 20 46 41 54 31 32 20 20 20 0e 1f |ME FAT12 ..|
00000040 be 5b 7c ac 22 c0 74 0b 56 b4 0e bb 07 00 cd 10 |.[|.".t.V.......|
00000050 5e eb f0 32 e4 cd 16 cd 19 eb fe 54 68 69 73 20 |^..2.......This |
00000060 69 73 20 6e 6f 74 20 61 20 62 6f 6f 74 61 62 6c |is not a bootabl|
00000070 65 20 64 69 73 6b 2e 20 20 50 6c 65 61 73 65 20 |e disk. Please |
00000080 69 6e 73 65 72 74 20 61 20 62 6f 6f 74 61 62 6c |insert a bootabl|
00000090 65 20 66 6c 6f 70 70 79 20 61 6e 64 0d 0a 70 72 |e floppy and..pr|
000000a0 65 73 73 20 61 6e 79 20 6b 65 79 20 74 6f 20 74 |ess any key to t|
000000b0 72 79 20 61 67 61 69 6e 20 2e 2e 2e 20 0d 0a 00 |ry again ... ...|
000000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200 f8 ff ff 00 f0 ff 00 00 00 00 00 00 00 00 00 00 |................|
00000210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000400 f8 ff ff 00 f0 ff 00 00 00 00 00 00 00 00 00 00 |................|
00000410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000600 4e 41 4d 45 20 20 20 20 20 20 20 20 00 00 00 00 |NAME ....|
00000610 00 00 00 00 00 00 21 86 91 4b 03 00 0c 00 00 00 |......!..K......|
00000620 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00004e00 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a 00 00 00 00 |hello world.....|
00004e10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00019000
After deleting file name we can see change in hexdump
00000600 4e 41 4d 45 20 20 20 20 20 20 20 20 00 00 00 00 |.AME ....|
00000610 00 00 00 00 00 00 21 86 91 4b 03 00 0c 00 00 00 |......!..K......|
00000620 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
And here is my question do you have any suggestion how can i change fat.img to .AME to NAME to recovery my file?
how can i change fat.img to .AME to NAME to recovery my file?
The short answer is with dd, an example with the necessary caveats follows below.
Adding to Martin's answer, while manipulating the bytes to restore the file within the floppy image is a relatively straight-forward proposition with dd, computing where and what within the file allocation table(s) needs to be restored is the challenge. Walking through the use of dd to restore the file itself, knowing what bytes need attention is illustrated by the following example.
Creating a floppy image to work with saves you from having to experiment on your actual image. Simply duplicate your image you wish to work with, or create a new one within a file on your hard drive. You can do that easily with mkfs.msdos (adjust the filesystem type as needed), and then mount the file within your filesystem as follows, e.g.
$ mkfs.msdos -C /home/david/tmp/tt/floppy_144.img 1440
$ sudo mount /home/david/tmp/tt/floppy_144.img /mnt/fd
Now let's add the NAME file:
$ echo "hello world" > NAME
$ sudo cp -a NAME /mnt/fd
$ ls -l /mnt/fd
total 1
-rwxr-xr-x 1 root root 12 Dec 17 13:55 NAME
$ cat /mnt/fd/NAME
hello world
Before deleting the file from your image, hexdump the contents so you can see exactly what needs to be restored. (this is what you must compute in order to know where and what to restore with your original image, you will need to consult a reference for the precise filesystem at issue)
$ hexdump -C floppy_144.img >flpwname.txt
Now delete the file from your image and again save a hexdump showing the changes.
$ sudo rm /mnt/fd/NAME
$ hexdump -C floppy_144.img >flpwoname.txt
Now you can examing the difference with diff. What you find is you must restore more than the first name of the file that was deleted, you will need to restore the file allocation table entries so that the restored file can again be located within the filesystem (both copies of the FAT), e.g.
$ diff flpwname.txt flpwoname.txt
16c16
< 00000200 f0 ff ff 00 f0 ff 00 00 00 00 00 00 00 00 00 00 |................|
---
> 00000200 f0 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
19c19
< 00001400 f0 ff ff 00 f0 ff 00 00 00 00 00 00 00 00 00 00 |................|
---
> 00001400 f0 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
22c22
< 00002600 4e 41 4d 45 20 20 20 20 20 20 20 20 00 00 fa 9e |NAME ....|
---
> 00002600 e5 41 4d 45 20 20 20 20 20 20 20 20 00 00 fa 9e |.AME ....|
Note above the entries for the file allocation table(s) at 0x204 and 0x1404 were zeroed when the file was removed. Restoring the bytes to the original can be easily done with dd but pay attention to your options. Specifically your block size (bs), output block size (obs), count and seek must all be in bytes (specified by appending c) to the number and you must set the notrunc conversion option to prevent truncating your image following the changes you make. Lastly, all sizes must be specified in decimal not hexadecimal.
Further, if you are using bash, you can use a process redirection to specify the bytes to replace (e.g. if=<(printf "\xf0\xff") to write the hex bytes f0 and ff), otherwise, you will have to prepare input files containing your replacement strings. The dd commands to restore the FAT and the first character of the filename are fairly simple (consult man 1 dd for option explanation).
Below we restore the first copy of the FAT, then the second, and finally restore the first character of the filename. The seek (offset) values are just those provided by hexdump converted to decimal. (you should unmount your filesystem before making changes. you can make changes while your floppy image is mounted, but they won't be reflected until you remount)
$ sudo umount /mnt/fd
$ dd if=<(printf "\xf0\xff") of=floppy_144.img \
bs=1c obs=1c count=2c seek=516c conv=notrunc
$ dd if=<(printf "\xf0\xff") of=floppy_144.img \
bs=1c obs=1c count=2c seek=5124c conv=notrunc
$ dd if=<(printf "N") of=floppy_144.img \
bs=1c obs=1c count=1c seek=9728c conv=notrunc
Now you can create a hexdump of the repaired floppy image and compare that to the original. If all has gone as it should, there will be no difference.
$ hexdump -C floppy_144.img >flprepair.txt
$ diff flpwname.txt flprepair.txt
Finally, just remount your filesystem and confirm the file has been restored.
$ sudo mount /home/david/tmp/tt/floppy_144.img /mnt/fd
$ ls -l /mnt/fd
total 1
-rwxr-xr-x 1 root root 12 Dec 17 13:55 NAME
$ cat /mnt/fd/NAME
hello world
That's it. I hope this is what you were looking for. There are a number of tools that automate this process for you, but dd and a pencil and paper can get you by.
The full hexdumps follow for completeness:
Original/Restored
$ cat flpwname.txt
00000000 eb 3c 90 6d 6b 66 73 2e 66 61 74 00 02 01 01 00 |.<.mkfs.fat.....|
00000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00 |...#............|
00000020 00 00 00 00 00 01 29 2c 72 18 ba 4e 4f 20 4e 41 |......),r..NO NA|
00000030 4d 45 20 20 20 20 46 41 54 31 32 20 20 20 0e 1f |ME FAT12 ..|
00000040 be 5b 7c ac 22 c0 74 0b 56 b4 0e bb 07 00 cd 10 |.[|.".t.V.......|
00000050 5e eb f0 32 e4 cd 16 cd 19 eb fe 54 68 69 73 20 |^..2.......This |
00000060 69 73 20 6e 6f 74 20 61 20 62 6f 6f 74 61 62 6c |is not a bootabl|
00000070 65 20 64 69 73 6b 2e 20 20 50 6c 65 61 73 65 20 |e disk. Please |
00000080 69 6e 73 65 72 74 20 61 20 62 6f 6f 74 61 62 6c |insert a bootabl|
00000090 65 20 66 6c 6f 70 70 79 20 61 6e 64 0d 0a 70 72 |e floppy and..pr|
000000a0 65 73 73 20 61 6e 79 20 6b 65 79 20 74 6f 20 74 |ess any key to t|
000000b0 72 79 20 61 67 61 69 6e 20 2e 2e 2e 20 0d 0a 00 |ry again ... ...|
000000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200 f0 ff ff 00 f0 ff 00 00 00 00 00 00 00 00 00 00 |................|
00000210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00001400 f0 ff ff 00 f0 ff 00 00 00 00 00 00 00 00 00 00 |................|
00001410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00002600 4e 41 4d 45 20 20 20 20 20 20 20 20 00 00 fa 9e |NAME ....|
00002610 91 4b 91 4b 00 00 f5 9e 91 4b 03 00 0c 00 00 00 |.K.K.....K......|
00002620 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00004400 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a 00 00 00 00 |hello world.....|
00004410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00168000
After NAME Deletion
$ cat flpwoname.txt
00000000 eb 3c 90 6d 6b 66 73 2e 66 61 74 00 02 01 01 00 |.<.mkfs.fat.....|
00000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00 |...#............|
00000020 00 00 00 00 00 01 29 2c 72 18 ba 4e 4f 20 4e 41 |......),r..NO NA|
00000030 4d 45 20 20 20 20 46 41 54 31 32 20 20 20 0e 1f |ME FAT12 ..|
00000040 be 5b 7c ac 22 c0 74 0b 56 b4 0e bb 07 00 cd 10 |.[|.".t.V.......|
00000050 5e eb f0 32 e4 cd 16 cd 19 eb fe 54 68 69 73 20 |^..2.......This |
00000060 69 73 20 6e 6f 74 20 61 20 62 6f 6f 74 61 62 6c |is not a bootabl|
00000070 65 20 64 69 73 6b 2e 20 20 50 6c 65 61 73 65 20 |e disk. Please |
00000080 69 6e 73 65 72 74 20 61 20 62 6f 6f 74 61 62 6c |insert a bootabl|
00000090 65 20 66 6c 6f 70 70 79 20 61 6e 64 0d 0a 70 72 |e floppy and..pr|
000000a0 65 73 73 20 61 6e 79 20 6b 65 79 20 74 6f 20 74 |ess any key to t|
000000b0 72 79 20 61 67 61 69 6e 20 2e 2e 2e 20 0d 0a 00 |ry again ... ...|
000000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200 f0 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00001400 f0 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00001410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00002600 e5 41 4d 45 20 20 20 20 20 20 20 20 00 00 fa 9e |.AME ....|
00002610 91 4b 91 4b 00 00 f5 9e 91 4b 03 00 0c 00 00 00 |.K.K.....K......|
00002620 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00004400 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a 00 00 00 00 |hello world.....|
00004410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00168000
I am unable to unzip file in linux centos. Getting following error
End-of-central-directory signature not found. Either this file is not
a zipfile, or it constitutes one disk of a multi-part archive. In the
latter case the central directory and zipfile comment will be found on
the last disk(s) of this archive.
As you are mentioning jar in your comments we can consider this a programming question ;-)
First of all you should try to validate your file. If available you can even compare the checksum provided for this file and / or the filesize with the location you downloaded it from.
To verify the zip file on a low level you can use this command:
hexdump -C -n 100 file.zip
This will show you the first 100 bytes of the zips structure which will look similar to this:
00000000 50 4b 03 04 0a 00 00 00 00 00 88 43 65 47 11 7a |PK.........CeG.z|
00000010 39 1e 15 00 00 00 15 00 00 00 0e 00 1c 00 66 69 |9.............fi|
00000020 6c 65 31 69 6e 7a 69 70 2e 74 78 74 55 54 09 00 |le1inzip.txtUT..|
00000030 03 0f 05 3b 56 2f 05 3b 56 75 78 0b 00 01 04 e8 |...;V/.;Vux.....|
00000040 03 00 00 04 e8 03 00 00 54 68 69 73 20 69 73 20 |........This is |
00000050 61 20 66 69 6c 65 0a 1b 5b 31 37 7e 0a 50 4b 03 |a file..[17~.PK.|
00000060 04 0a 00 00 |....|
The first two byte of the file have to be PK, if not the file is invalid. Some bytes later you will find the name of the first file stored. In this example it is file1inzip.txt.
I'm having trouble with my home made "for fun" nameserver. It's been a couple of months since I updated it so I'm a bit rusty and thought I'd ask here and see if someone else sees what's wrong. I'm getting a FORMERR when asking for a TXT record, and the same problem occur on different domains, so there's probably something wrong in the packet formatting. Anyone?
dig txt ffffff.com #ns1.ffffff.com
;; Got bad packet: FORMERR
1024 bytes
ce bf 84 00 00 01 00 01 00 02 00 00 06 66 66 66 .............fff
66 66 66 03 63 6f 6d 00 00 10 00 01 c0 0c 00 10 fff.com.........
00 01 00 00 02 58 00 13 12 57 65 6c 63 6f 6d 65 .....X...Welcome
20 74 6f 20 66 66 66 66 66 66 66 00 c0 0c 00 02 .to.fffffff.....
00 01 00 00 02 58 00 10 03 6e 73 31 06 66 66 66 .....X...ns1.fff
66 66 66 03 63 6f 6d 00 c0 0c 00 02 00 01 00 00 fff.com.........
02 58 00 10 03 6e 73 32 06 66 66 66 66 66 66 03 .X...ns2.ffffff.
63 6f 6d 00 00 00 00 00 00 00 00 00 00 00 00 00 com.............
In the example above supplied, I added an incorrect 00 (null terminator) at the end of the TXT-string. After removing the null terminator from the TXT records, the txt records now work on my nameserver.