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.
Related
I want to configure mplayer to look for an edl when playing a video. Specifically, I want it to use "show.edl" when playing "show.mp4", assuming both are in the same directory. Very similar to how it looks for subtitles.
I can add a default edl in the config file by adding the following:
edl=default.edl
And this will look for the file "default.edl" IN THE CURRENT DIRECTORY, rather than in the directory where the media file is. And it isn't named after the media file either, and thus even if it did look in the right place, I'd have one single edl file for every media file in that directory.
Not really what I wanted.
So, is there a way, in the "~/.mplayer/config" file, to specify the edl relative to the input file name?
Mplayer's config file format doesn't seem to support any sort of replacement syntax. So there's no way to do this?
MPlayer does not have a native method to specify strings in the config file relative to the input file name. So there's no native way to deal with this.
There's a variety of approaches you could use to get around that. Writing a wrapper around mplayer to parse out the input file and add an "-edl=" parameter is fairly general, but will fail on playlists, and I'm sure lots of other edge cases. The most general solution would of course be to add the functionality to mplayer's config parser (m_parse.c, iirc.)
The simplest, though, is to (ab)use media-specific configuration files.
pros:
Doesn't require recompiling mplayer!
Well defined and limited failure modes. I.E. the ways it fails and when it fails are easily understood, and there aren't hidden "oops, didn't expect that" behaviors hidden anywhere.
Construction and updating of the edl files is easily automated.
cons:
Fails if you move the media around, as the config files need to full path to the edl file to function correctly.
Requires you have a ".conf" file as well as an EDL file, which adds clutter to the file system.
Malicious config files in the media directory may be a security issue. (Though if you're allowing general upload of media files, you probably have bigger problems. mplayer is not at all a security-hardened codebase, nor generally are the codecs it uses.)
To make this work:
Add "use-filedir-conf=yes" to "/etc/mplayer.conf" or "~/.mplayer/config". This is required, as looking in the media directory for config files is turned off by default,
For each file "clip.mp4" which has an edl "clip.edl" in the same directory, create a file "clip.mp4.conf" which contains the single line "edl=/path/to/clip.edl". The complete path is required.
Enjoy!
Automatic creation and updating of the media-specific .conf files is left as an exercise for the student.
I uploaded Fabian Vogt's micropython port to my TI Nspire CX CAS, together with a couple of *.py.tns files to try. I can't find a way to load/launch those files.
As micropython does not include the os module, I can't use os.chdir to change the current directory and load the *.py files from the python shell. I tried from python shell: open("documents/mydirectory/myfile")
with different extensions .py or .py.tns, without success.
I don't think the Nspire has anything like the terminal commmand line either.
Thanks for your help,
There are 2 ways that you could do this, one easy way and one tedious way.
1. Map .py to micropython in your ndless.cfg
(ndless.cfg should be at /documents/ndless/ndless.cfg)
Like so:
ext.xxx=program-name
ext.xxx=program-name
ext.txt=nTxt
ext.py=micropython
ext.xxx=program-name
ext.xxx=program-name
You can edit this file either by copying it back and forth from your computer using TiLP or the official software, or you can edit it on-calc using nTxt. (This requires a bit of fiddling with making a copy of ndless.cfg so that the mappings still exist to open the copied file ndless.txt).
Ndless should come with a standard ndless.cfg containing basic bindings for nTxt and a few popular emulators. If you don't have one, get the standard one here. It will scan all directories (at least /documents/*, AFAIK) for programs. I've found that removing lines related to programs not on your Nspire will decrease load time.
2. Proper way to run a file in Python
To run a file in Python, you should do something like this:
with open("/documents/helloworld.py.tns","r") as file:
exec(file.read())
This will properly close the file after executing, which I've noticed is quite important on the Nspire, as leaving files open has given me trouble before. Of course, if you'd like, you can do exec(open("...","r").read()) and then handle closing the file yourself, but be warned: bad things can happen if you forget.
Also, you must remember to add the leading / and the .tns extension, or else strange things will happen, especially with writing to files.
That's about it! Feel free to ask more questions if needed, I'll be watching the ti-nspire tag.
(Just realized this question is quite old, but I guess it still might be helpful for others who end up on empty questions months later while trying to figure something out :P)
I am using the xmlpoke task in nant and am looking for a way to use a wildcard when addressing the xml file. Right now I have a file path like project\appFiles\project{versionNumber}\fileToUpdate.xml, I would like to use a wildcard so its something like project\appFiles\project*\fileToUpdate.xml so I don't have to update the version number every time.
How do you get it to respect wildcards?
Looking all over the web, it doesn't look like this is possible, and by design. Like copy command (todir), the file path must point to a single file so no wildcards allowed (Found info on copy command, assuming same applies for XMLPoke, but could confirm exactly).
I ended up changing some design stuff so now the version number is easily calculated by the program calling the script, so passing in not an issue anymore.
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.
Basically I have two schemas on the same DB that I would like to put into a dot file using postgresql_autodoc. I have tied creating two separate .dot files and then packing them with gvpack.
However I run into an error telling that the first node in one of the files does not have a position.
I've also tried just combining the two graphs without packing and then running the command I found on stackoverflow (ccomps -x graph.dot | dot | gvpack -array3 | neato -Tsvg -n2 -o graph.svg), but it seems that the connections are not there.
Perhaps there is another program I could use that will create a master dot that contains the two schemas?
My ultimate goal here is to make it completely automated using a php and shell script combo that I can run after making changes and pull subsystems out of it using gvpr.
Let me know what you think guys! (64bit Ubuntu 12.04.2 - in case that's also needed)
This may seem like a bit simple, because I haven't worked with the .dot files much but we use pg_autodoc to generate files with all schemas in a database. We haven't had any problems.
So the first thing to do is just to run pg_autodoc on your database and generate a .dot file without selecting schemas. This will give you all objects in all schemas.
If that fails to give you something you can use with your toolchain, then the next question is why, but that will have solved your immediate question.