I'm writing a tool in Perl that needs to scan for certain binary patterns inside an executable file on a Mac OSX. To avoid getting very many false positives, I want to restrict my search to the data/text segment of the executable, excluding the code segment and a few other things. How can I accomplish this?
How about using otool?
-t Display the contents of the (__TEXT,__text) section.
-d Display the contents of the (__DATA,__data) section.
You should look at the ELF file format specification. It contains headers and tables that tell you exactly which segments live where. Parsing it is tedious but straightforward.
Related
I have a bunch of text files that need cleaning up. Example
`E..4B?#.#...
..9J5.....P0.z.n9.9.. ........
.k#a..5
E...y^#.r...J5..
E...y_#.r...J5..
..9.P..n9..0.z............
….2..3..9…n7…..#.yr`
Is there any way sed can do this? Like notice weird patterns?
For this answer, I will assume that you have access to standard unix/linux tools.
Your file might be in some word-processor format. If so, the best way to get rid of the junk is to open it with that program. You may be able to find out which with file:
$ file mysteryfile
mysteryfile: Composite Document File V2 Document, Little Endian, Os: Windows, Version 6.1 ....
If that doesn't work, there is a standard unix utility for extracting text from binary files. It is called strings:
$ strings mysteryfile
Some
Recovered Text
...
The behavior of strings can be fine tuned with several options. See man strings.
I am looking for a tool that would ease the modification of text configuration files for tasks like:
Set ForwardAgent yes on /etc/ssh/ssh_config
Append HGUSER to AcceptEnv in /etc/ssh/sshd_config (that's more complex as it does accept several params, if yours is not alread there it should add it)
Most important:
running it several times should have no side effects.
if something looks weird, it should complain (for example if you find the same line several times in a file, or if the expected syntax does not match).
Is there any linux tool that can easily be used to automate things like this?
The whole point is to be able to write these config patches somewhere so you can deploy them on several machines or on a new machine when needed.
I would certainly do this with bash scripting. Here is a great tutorial.
http://linuxconfig.org/Bash_scripting_Tutorial
to change a line in a file you could do something like:
check the file exists
grep for the value you want to change - error if it appears multiple times or something
use sed to change that line
to append something to a file
check if file exists
grep to ensure it hasn't been appended to already
echo whatever >> file - the double greater than appends to a file
with each of these I would make a backup copy of the file first, just in case something goes wrong
You might want to have a look at the Unified Configuration Interface (UCI) used in Embedded Linux systems. If you have the flexibility to adapt the UCI format for your config files, this is pretty similar to what you are looking for.
I have an exe file(eg naming.exe) on my Solaris server.
I want to see the contents of the exe file.
Is it possible ?
See the strings command which will extract readable text from a file. See the article on wikipedia for more about it.
Although Solaris and Unix in general doesn't care that much about suffixes, especially for executables.".exe" isn't a common file suffix there, it looks like a Windows thing to me.
Start by running file naming.exe to get an idea about what kind of file it is.
Often data beyond simply strings is packed in too. (For example software installers sometimes have useful cross-platform data files embedded within executable files). On linux you can extract this using cabextract. I can't see any reason why porting this to Solaris would be hard if it isn't already working on Solaris.
I'm trying to grok gettext.
Here's how I think it works -
First you use some sort of po editor and tell it to scan a directory for your application, create these ".po" files, the application makes a po file for each file scanned which contains a string in a programming language, then compile them to binary mo files, to which gettext parses, and you call a method using a high level API such as Zend_Translate and specify you want to use gettext, it can be setup to cache translations and it just returns those.
The part I'm really unclear about is how the editing of po files is done really, it's manual - right? Then when the compilation is done of course the application relies on the binary mo files.
And if someone could provide useful linux applications for editing .po files I'd be grateful.
The tutorial on NLS using GNU gettext should help you understand the process.
As for editing .po files, there's at least two applications (apart from vi :-): gtranslator and poedit.
Does anyone know of a free Perl program (command line preferable), module, or anyway to search and replace text in a PDF file without using it like an editor.
Basically I want to write a program (in Perl preferably) to automate replacing certain words (e.g. our old address) in a few hundred PDF files. I could use any program that supports command line arguments. I know there are many modules on CPAN that manipulate or create pdfs but they don't have (that I've seen) any sort of simple search and replace.
Thanks in advance for any and all advice!!!
Take a look at CAM::PDF. More specifically the changeString method.
How did you generate those PDFs in the first place? Search-and-replace in the original sources and re-generate PDFs seems to be more viable. Direct editing PDFs can be very difficult, and I'm not aware of any free tools that can do it easily.