I'm trying to write a small programme that needs to load a few files chosen by the user. I thought it'd be easier to use the Linux system's default file picker rather than write my own, but I literally don't have a clue where to even start looking.
So, can anyone recommend a quick and easy way to use the system's file picker on Linux in C?
As I commented, many Linux systems (e.g. a rented VPS, a consumer router box, ...) don't have any graphical user interfaces (often above X11).
If you want a GUI toolkit in C for Linux, consider using GTK. Then look at GtkFileChooserWidget & GtkFileChooser
If you want a GUI toolkit in C++ for Linux, consider using Qt.
If you want a terminal interface, learn ncurses.
If you want a web interface, use some HTTP server library like libonion or Wt, or make a FastCGI program for your existing web server.
Perhaps coding a simple shell script might be easier. Read Advanced Bash Scripting Guide. You could also use a scripting language like Python, Ruby, Ocaml, ...
If you don't know about Linux programming, read Advanced Linux Programming first. See also intro(2) & intro(3)
... a small program that needs to load a few files chosen by the user.
Just pass them as command-line arguments. It's much easier and doesn't tie you to a given GUI toolkit.
You can easily write a shell wrapper using kdialog on KDE, or dialog if you want curses in a terminal, or ... whatever other tool for whatever other environment.
Related
I want to write in C a command line tool with the following requirements:
Few commands (<10)
History management through the arrows key
Capability to delete what I typed previously with baskspace
Capability to add keyborad shortcuts such as ctrl+l to clear the screen
Protable across UNIX systems
I am not asking for code here, but for indications about where to start. I first made some experiments with "scanf" and it quickly become quite complicated. I then looked at ncurses, and it seems also quite low level. Is there any C libraries dedicated to this task, where would you start ?
I then looked at ncurses, and it seems also quite low level
CDK (Curses Development Kit) - high-level wrapper over ncurses. I've had successful experience with it. When you need you always can use ncurses directly.
The GNU Readline library is exactly designed for that.
I'd like to write an application (in C) that uses the terminal of a *nix OS as its GUI. I mean an application of the kinds of emacs, vi etc. that take up the whole terminal window and jump back to the input prompt after quitting.
How would you go about doing that, preferably in C? Can someone point me to a tutorial covering that?
You need to use ncurses:
http://en.wikipedia.org/wiki/Ncurses
http://tldp.org/HOWTO/NCURSES-Programming-HOWTO/
It is available on all major distros.
Well, actually this is not GUI (graphic user interface) but a text based interface. You can use the library ncurses to create such applications in C.
Use a library like ncurses, it is specifically designed for this purpose.
Throwing in alternate solutions so that this question thread does not look so monotonic:
the slang library (mc uses it, for example)
In our Bioinformatics lab we've recently been asked to create a GUI for a program written (and optimized) in C. Any GUI we designed would need to be able to feed input to and receive output from the C program, while also being easily portable to both Windows and Mac. What are ways to go about doing this?
If your looking for a GUI toolkit that works on windows/mac in C, have you considered GTK?
Download QT or wxWidgets.
Why do the hard work when someone already has and will let you use it for free? I prefer QT myself, btw.
Edit: It does mean using C++ but it will work perfectly with C code.
Use a separate program.
It doesn't break the existing code - especially important if the code has bio knowledge that a programmer might not know/understand/test.
Gui's change often, in a couple of years you are going to be rewriting the gui for NewSuperOsToolkit(tm) but the underlying worker code won't change. We have atmospheric modelling code that I'm sure was originally written in latin.
You keep the ability to run the engine code as a batch, in parallel on MPI in the cloud, and a bunch of other ways you haven't thought of.
You could write the front end GUIs in Java, and have them feed input and receive output from your C programs. I've known a couple of groups here at work that do something similar with C# and C code (but they don't have the multi-platform restraint).
This way you don't necessarily have to create your GUIs using a C toolkit.
Depending on the nature of the program, you could create an entirely separate GUI application (in any language you prefer), and fork/execute the existing program from it, redirecting it's stdin and stdout to your GUI program. Depending on how the existing program works, this could work well, or be very cumbersome.
You could also extend the existing program with GUI code in something like GTK (which has a C API), or you could use Qt (which is C++, but there's usually no problems calling C functions from C++ if you define them as 'extern "C"').
There are a number of scripting with languages that can make this easy. I'd go for tcl/tk it works on mac pretty much out of the box, and is cross platform across pretty much any machine you can think of.
Also GTK is great and a number of scripting languages have bindings for it.
You probably don't want to write your gui in c if you don't have to. use a rapid develoment scripting language.
If you want a native GUI, then go with wxWidgets or QT. (I use wxWidgets ...)
The alternative is to have an HTML based interface using Javascript and CSS. You avoid GUI libraries altogether, you get cross-platform support and the outcome is better on some dimensions, worse on others.
If you really want a standalone user interface, you can integrate it into a binary with something like WebKit.
I'm working on a project that's supposed to work on both Windows and Linux (with an unofficial Mac port as well) that emulates a true colour system console.
My problem is that recently there appeared a request for textfield support (yes, console-based) and it would be cool to add the possibility of copying text to clipboard and pasting from it. Is there a way of achieving this that will:
be done in C (not C++),
work in both Windows and in Linux (preprocessor macros are an option if there's no platform-independent code),
require no extra libraries to link to?
Thanks in advance for your help.
If you're not using a cross platform UI library (like wx or something), then it sounds like you're just going to have to write native clipboard code for each platform you want to support.
Remember, on Macintoshes, you copy with Command-C, not Ctrl+C :)
The clipboard is inherently an operating system defined concept. The C language itself has no knowledge of what a clipboard is or how to operate on it. You must either interface directly with the OS, or use a portability library that does this on your behalf. There is no way around this.
Personally I would define my your own function
getClipboardText();
That is defined in two different header files (linux_clipboard.h, windows_clipboard.h, etc) and then do pre-proccessor stuff to load the appropriate one accordingly. I don't really code in C/C++ so I'm sorry if that didn't make any sense or is bad practice but that's how I'd go about doing this.
#if WIN32
#include windows_clipboard.h
#endif
That sort of thing
Remember:
For linux you have to deal with different window managers (Gnome, KDE) all with different ways of managing the clipboard. Keep this in mind when designing your app.
You may be able to communicate to the clipboard by using xclip. You can use this python script here to do this job via communicating with 'dcop' and 'klipper' here. That is for KDE, I do not know how it would be done under GNOME... You may also be able to do this independantly of either GNOME/KDE by using DBUS, although I cannot say 100% confidently on that either...
Just be aware, that for a truly cross-platform job, you have to take into account of the different GUI's such as under Linux, X is the main window manager interface and either GNOME/KDE sits on top of it..I am not singling out other GUI's such as FluxBox, WindowMaker to name but a few, and that there will be a lot of platform dependant code, and also in conjunction, you will be dealing with Windows clipboard as well..all in all, a big integrated code...
Have you not considered looking at the raw X programming API for clipboard support? Maybe that might be better as I would imagine, GNOME/KDE etc are using the X's API to do the clipboard work...if that is confirmed, then the work would be cut out and be independant of the major GUI interfaces...(I hope that would be the case as it would make life easier for your project!)
Perhaps using compile-time switches, for each platform...WIN, KDE, GNOME, MAC or use the one that is already pre-defined..
Hope this helps,
Best regards,
Tom.
I think the thing I want to do is called GUI/command line wrapping sftp(1). I need an easy way to start that program and react on its output while running. Additionally I have to be able to send input to it, full interaction is required.
I tried forkpty (emulated TTY), but there wasn't one good example findable using forkpty for that job, instead several warnings about overflows in in arguments and advisories not to use it. Another weird thing about this was the windowsize argument...
Please either give me one or many example(s) on how to call & interact with command line programs in C or another way of integrating sftp in an iPhone GUI
Rejoice! Expect was created to solve exactly your problem. It's based on Tcl, which is not so pleasant, but the tool is pleasant, it's really well designed, and there's a good book by Don Libes, who created the tool.
Expect scripts are written in Tcl, but it is totally easy to integrate a Tcl script into a C program such that other parts of the C program don't even know that Tcl is being used.
Have you used any of the popular scripting languages Ruby/Python/Perl/etc? They all have pretty full featured libraires for opening and communicating with other processes.
the subprocess module in python for example, or Popen in Ruby... there would also be lots of reference material around the web to help you out.
If a GUI was also required you could look at GTK extensions
Instead of calling sftp(1), how about using libssh? It has full sftp subsystem support.