I have built a linux image for ARM on Ubuntu. I was curious to use the file command on the image file created in arch/arm/boot directory. When i execute the following the command
balaji#balaji-virtual-machine:~/meraj/linux-stable/arch/arm/boot$ ls
bootp compressed dts Image install.sh Makefile zImage
balaji#balaji-virtual-machine:~/meraj/linux-stable/arch/arm/boot$ file Image
Image: data
balaji#balaji-virtual-machine:~/meraj/linux-stable/arch/arm/boot$ file zImage
zImage: data
balaji#balaji-virtual-machine:~/meraj/linux-stable/arch/arm/boot$
It gives not much information. I would like to know if this is expected behaviour or not?
From file manpage:
The type printed will usually contain one of the words...
... "data" meaning anything else (data is usually 'binary' or non-printable).
Exceptions are well-known file formats (core files, tar archives) that
are known to contain binary data.
Also...
Any file that cannot be identified as having been written in any of
the character sets listed above is simply said to be 'data'.
Related
Do you know which system call the Linux file command uses to determine the type of file?
On the command line, if you use the file command it will reply with something like:
dev-1:~/$ file download.png
download.png: PNG image data, 724x 724, 8-bit/color RGBA, non-interlaced
Is this an entire routine that does that? Or is there a system call that maps to that functionality?
On the suggestion of #stark I ran the Linux strace command like the following:
$ strace file download.png
A lot of info is returned (many system calls) but I picked through it and found the core item I was looking for:
fstat(3, {st_mode=
I searched and found a man page for fstat:
These functions [lstat, fstatat] return information about a file, in the buffer pointed
to by statbuf.
There is also a call (or calls) to pread64() which reads from the file descriptor.
Hi I've some helpful Linux file commands for you hope it will be useful below
file bobs_file.txt
output = bobs_file.txt: ASCII
file textfile.tar
output = textfile.tar: POSIX tar archive (GNU)
file Picture/
output = Pictures/: directory
file iuk.png
output = iuk.png: PNG image data, 213 x 213, 8-bit/color RGB, non-interlaced
I have a vmlinuz ELF image file. I need to get the kernel version from the image file without disassembling it. Is it possible to get kerenel version from offsets of that compressed image file? The file is ELF 64-bit MSB executable, statically linked, not stripped.
As previously mentioned, the version number is hardcoded into the compressed image file. First it depends on the compression algorithm used to compress the content, how to decompress it.
Decompressing files in linux could be challenging due to the combination of compression algorithms and the correlated tool options (not to forget a newer version of tar for newer algorithms).
For files with
file extension tar.gz, tgz use e.g. $ tar -xzv -f vmlinuz.tgz
file extension tar.xz, use e.g. $ tar -xJv -f vmlinuz.tar.xz
file extension tar.bz2, use e.g. $ tar -xjv -f vmlinuz.tar.bz2
So if you have access to the file utility (should also run on windows), run the following to receive the version string and additional information of your file named e.g. vmlinuz-4.x.y-z-a.
file vmlinuz-4.x.y-z-a
Another possibility to reverse-engineer would be to read all strings of the binary file vmlinuz-4.x.y-z-a and grep for a part of the possible solution.
strings vmlinuz-4.x.y-z-a | grep 'linked,'
I use a program which create me postscript file before using ps2pdf to make it a readable pdf, i've made a program which add some string to overwrite the company new logo. (The first program can't import image file itself).
I add the string before the before-last line of the file (" showpage").
While running my program to add the logo there is no error.
With the option -dNOSAFER everything is fine, but by default it's set to -dSAFER, and an invalidfileaccess error pop, the files are 6 jpg images alone in their directory.
I don't want to make it run with the -dNOSAFER option on. As it will fully open the file system.
In the documentation I've seen that there is a "permitted path" setting, but i can't find nowhere to set this up. Is it just a command line option to set in the command launching the program ? Or is there a config file for GhostScript / ps2pdf where i can put the path to this directory as permitted path.
in this documentation :
http://www.ghostscript.com/doc/current/Use.htm
I only find
-dTTYPAUSE
Causes Ghostscript to read a character from /dev/tty, rather than
standard input, at the end of each page. This may be useful if input
is coming from a pipe. Note that -dTTYPAUSE overrides -dNOPAUSE. Also
note that -dTTYPAUSE requires opening the terminal device directly,
and may cause problems in combination with -dSAFER. Permission errors
can be avoided by adding the device to the permitted reading list
before invoking safer mode
gs -dTTYPAUSE -dDELAYSAFER -c '<< /PermitFileReading [ (/dev/tty)] >> setuserparams .locksafe' -dSAFER
The quote is just for the context but is this a way to put the permitted path ?
As gs automatically launch with the full system as readOnly there will be no difference ? There is no other find result for PermitFile in this page.
Try adding the required path to the search path with -I (Include) See Use.htm, section 8 How Ghostscript finds files. This should only be a problem if you are using 'run' or similar to read files from another location.
The section on TTYPAUSE is not relevant.
I am trying to zip a file using shell script command. I am using following command:
zip ./test/step1.zip $FILES
where $FILES contain all the input files. But I am getting a warning as follows
zip warning: name not matched: myfile.dat
and one more thing I observed that the file which is at last in the list of files in a folder has the above warning and that file is not getting zipped.
Can anyone explain me why this is happening? I am new to shell script world.
zip warning: name not matched: myfile.dat
This means the file myfile.dat does not exist.
You will get the same error if the file is a symlink pointing to a non-existent file.
As you say, whatever is the last file at the of $FILES, it will not be added to the zip along with the warning. So I think something's wrong with the way you create $FILES. Chances are there is a newline, carriage return, space, tab, or other invisible character at the end of the last filename, resulting in something that doesn't exist. Try this for example:
for f in $FILES; do echo :$f:; done
I bet the last line will be incorrect, for example:
:myfile.dat :
...or something like that instead of :myfile.dat: with no characters before the last :
UPDATE
If you say the script started working after running dos2unix on it, that confirms what everybody suspected already, that somehow there was a carriage-return at the end of your $FILES list.
od -c shows the \r carriage-return. Try echo $FILES | od -c
Another possible cause that can generate a zip warning: name not matched: error is having any of zip's environment variables set incorrectly.
From the man page:
ENVIRONMENT
The following environment variables are read and used by zip as described.
ZIPOPT
contains default options that will be used when running zip. The contents of this environment variable will get added to the command line just after the zip command.
ZIP
[Not on RISC OS and VMS] see ZIPOPT
Zip$Options
[RISC OS] see ZIPOPT
Zip$Exts
[RISC OS] contains extensions separated by a : that will cause native filenames with one of the specified extensions to be added to the zip file with basename and extension swapped.
ZIP_OPTS
[VMS] see ZIPOPT
In my case, I was using zip in a script and had the binary location in an environment variable ZIP so that we could change to a different zip binary easily without making tonnes of changes in the script.
Example:
ZIP=/usr/bin/zip
...
${ZIP} -r folder.zip folder
This is then processed as:
/usr/bin/zip /usr/bin/zip -r folder.zip folder
And generates the errors:
zip warning: name not matched: folder.zip
zip I/O error: Operation not permitted
zip error: Could not create output file (/usr/bin/zip.zip)
The first because it's now trying to add folder.zip to the archive instead of using it as the archive. The second and third because it's trying to use the file /usr/bin/zip.zip as the archive which is (fortunately) not writable by a normal user.
Note: This is a really old question, but I didn't find this answer anywhere, so I'm posting it to help future searchers (my future self included).
eebbesen hit the nail in his comment for my case (but i cannot vote for comment).
Another possible reason missed in the other comments is file exceeding the file size limit (4GB).
I converted my script for unix environment using dos2unix command and executed my script as ./myscript.sh instead bash myscript.sh.
I just discovered another potential cause for this. If the permissions of the directory/subdirectory don't allow the zip to find the file, it will report this error. Actually, if you run a chmod -R 444 on the directory, and then try to zip it, you will reproduce this error, and also have a "stored 0%" report, like this:
zip warning: name not matched: borrar/enviar
adding: borrar/ (stored 0%)
Hence, try changing the permissions of the file. If you are trying to send them through email, and those email filters (like Gmail's) invent silly filters of not sending executables, don't forget that making permissions very strict when making zip compression can be the cause of the error you are reporting, of "name not matched".
spaces are not allowed:
it would fail if there are more than one files(s) in $FILES unless you put them in loop
I also encountered this issue. In my case, the line separate is CRLF in my zip shell script which causes the problem. Using LF fixed it.
I'm using ImageMagick to do some image processing from the commandline, and would like to operate on a list of files as specified in foo.txt. From the instructions here: http://www.imagemagick.org/script/command-line-processing.php I see that I can use Filename References from a file prefixed with #. When I run something like:
montage #foo.txt output.jpg
everything works as expected, as long as foo.txt is in the current directory. However, when I try to access bar.txt in a different directory by running:
montage /some_directory/#bar.txt
output2.jpg
I get:
montage: unable to open image
/some_directory/#bar.txt: No such file
or directory # blob.c/OpenBlob/2480.
I believe the issue is my syntax, but I'm not sure what to change it to. Any help would be appreciated.
Quite an old entry but it seems relatively obvious that you need to put the # before the full path:
montage #/some_directory/bar.txt output2.jpg
As of ImageMagick 6.5.4-7 2014-02-10, paths are not supported with # syntax. The # file must be in the current directory and identified by name only.
I haven't tried directing IM to pull the list of files from a file, but I do specify multiple files on the command line like this:
gm -sOutputFile=dest.ext -f file1.ppm file2.ppm file3.ppm
Can you pull the contents of that file into a variable, and then let the shell expand that variable?