Our application can generate some fairly long report files interactively. We use C++ to generate all the output, but redirected through a TCL console and TCL channel so we can take advantage of output logging etc.
Is there any common way to support paging of output in C++. I've casted around but can't find anything.
Best
Sam
OK, so the situation is that you're writing to a Tcl_Channel that a Tcl interpreter is also writing to. That should work. The simplest way to put paging on top of that is to make that channel be one of the standard channels (I'd pick stdout) and feed the whole lot through a pager program like more or less. That'll only take you a few seconds to get working.
Otherwise, it's possible to write a channel in Tcl 8.5 using just Tcl code; that's what a reflected channel is (that's the Tcl 8.6 documentation, but it works the same way in 8.5). However, using that to do a pager is going to be quite a lot of work; channels work with bytes not characters. It's probably also possible to do it using a stacked channel transformation (8.6 only).
However, if sending the output to a Tk text widget is acceptable (I know it isn't precisely what you asked for…) there's already a package in Tcllib for it.
package require Tk
package require tcl::chan::textwindow
pack [text .t]
set channel [tcl::chan::textwindow .t]
puts $channel "This is a simple test."
That (write-only) channel will work fine if you pass it to your C++ code to use. (You can inspect the source to see how it is done if you wish; the code is pretty short.)
Related
Is there a library/tool that can be used in C/C++ that would convert the PS (post script) file to .PDF file, on embedded platform (proprietary operating system, no windows, no linux)?
I was looking for some kind of library that could be ported to our OS. I have found basically only Ghostscript, but issue there is with the license, if i understood it correctly, we would have to make our source public, which is not possible for us...
Maybe a little bit more background, we are trying to find format that will be easily viewable by user. We already have our output in PS for other reasons (printer). But now we want to provide this output in file by itself, so we are trying to find feasible file format. We are considering the PS itself, but usual user does not have PS viewer, so that's why I am trying to find something to convert this to PDF. So perhaps alternative question could be, is there some another format that can be easily acquired from PS, such that "regular" user can view it?
The main complexity for converting PostScript to something else comes from the fact, that PostScript is a programming language and PostScrip files in fact are programs executed on the printer.
In contrast to PostScript, PDF is not a programming language. When converting PostScript to PDF (or anything else), you actually have to run the PostScript program and record the graphic primitive calls, executed during the execution of the PostScript program.
This general approach is needed, when you want to convert PostScript programs from any source to PDF.
But you wrote, that you are creating the PostScript code yourself. Perhaps your PostScript program is just a linear sequence of calls to drawing primitives and does not use anything like subroutines or control structures.
If not, it might be easy to change your generator to do those computation at creation time,that currently are performed at print time. You would end up in a linear sequence of calls to drawing primitives.
When there are no more computations done at print-time, it should not be too hard to directly create PDF instead of PostScript. This answer mentions an open source PDF generation library, that uses an MIT style license.
The AGPL licence for Ghostscript would require you to make your source open, yes. However Ghostscript is dual licenced, in addition to the AGPL licence you can purchase a commercial licence, which doesn't require you to open source your own code.
Rather than converting to PDF you can, of course, also simply use Ghostscript to render the PostScript to a bitmap, its usually pretty easy to wrap a viewer around that.
I should point out that there are other companies offering commercial licences for PostScript interpreters which are capable of creating PDF files and/or rendering PostScript. Adobe is the obvious one, there's also Global Graphics.
These days there are not many players left in the field, if you want to handle PostScript, and the AGPL or similar licences won't suit you, then you will need to go commercial.
Title says pretty much everything. Once upon a time when I was under 13, my older bro did in BorlandPascal a thing which amazed me. He defined kind of table [8][8] with values of 1 and 0, meaning respectively foreground and background. Having several of such tables he could somehow redefine default ASCII characters to look like in these tables. I have no idea how it was done, but it worked.
My question is: can I do similar thing in ncurses, and if I can then how to do it?
The short answer is no. What ncurses does is generating ANSI escape codes which are interpreted by the terminal. There are no codes for altering the font. (Althou there have been extensions propesed no commonly used terminal supports them, neither does ncurses.) And there is no generic way of communicating with the terminal through some kind of side channel for changing the font. But there might ways in some specific situations.
If you have direct access to a Linux console for example you could could do all sorts of things, much like in Borland Pascal. But it will likely be more messy and less impressive.
As the selected answer explains, this is not possible for NCurses to render custom glyphs. ncurses only manipulates the terminal screen state via escape codes (Clearing and rewriting lines to achieve interactivity).
However it should be noted that's very possible to use custom glyphs in the terminal via custom fonts.
This is what Powerline does (a popular terminal UI status line for vim, tmux and friends): https://github.com/powerline/fonts
By patching the fonts, you can inject your glyphs into the existing font being used by the terminal, which then you can access and render via ncurses as any other character.
Of course this is not ideal solution, but with some auto patching of the fonts, and careful testing, it makes it possible to build an app that uses custom glyphs—when your really in a pinch for more expressive UI tools than ncurses can offer.
Further reading: https://apw-bash-settings.readthedocs.io/en/latest/fontpatching.html
I like to print a document. The content of the document are tables and text with different colors. Does a lightwight printer-file-format exist, which can be used like a template?
PS, PDF, DOC files in my opinion are to heavy to parse. May there exist some XML or YAML file format which supports:
Easy creation (maybe with a WYSIWYG-Editor)
Parsing and manipulation with Library-Support
Easy sending to the printer (maybe with Library-Support)
Or do I have to do it the usual way and paint within a CDC?
I noticed you’re using MFC (so, Windows). In that case the answer is a qualified yes. In recent versions of Windows, Microsoft offers the XPS Document API which lets you create and manipulate a PDF-like document using XML, which can then be printed using the XPS Print API.
(For earlier versions of Windows that don’t support this API, you could try to deal with the XPS file format directly, but that is probably a lot harder than using CDC. Even with the API you will be working at a fairly low level.)
End users can generate XPS documents using the XPS print driver that is available for free from Microsoft (and bundled with certain MS products—they probably already have it on their system).
There is no universal language that is supported across all (or even many) printers. While PCL and PS are the most used, there are also printers which only work with specific printer drivers because they only support a proprietary data format (often pre-rendered on the client).
However, you could use XSL-FO to create documents which can then be rendered to a printer driver using library support.
I think something like TeX or LaTeX (or even troff or groff) may meet your needs. Google them and see.
There are also libraries to render documents for print from HTML source. Look at http://libharu.sourceforge.net/ for example. This outputs a printer-ready .PDF
A think that Post Script is a really good choice for that.
It is actually a very simple language, and it must be very easy to parse becuse it is stack-oriented. Then -- most printers supprort it, and even if you have no support you can use GhostScript to convert for many different formats (Consider GS as a "virtual PS supporting printer").
Finally there are a lot of books and tutorials for the language.
About the parsing -- you can actually define new variables and functions in PS. So, maybe, your problem can be solved (almost) entirely using PS.
HTML + CSS can be printed -- properly. CSS was designed to support this with the media attribute to specify that your CSS is for printer layout, not for screen layout. Tools like PRINCE (free + commercial versions) exist to render this for printing.
I think postscript is the markup language used by printers. I read this somewhere, so correct me if postscript is now outdated.
http://en.wikipedia.org/wiki/PostScript
For more powerful suite you can use Latex. It will give options of creating templates where you can just copy the text.
On a more GUI friendly note, MS-Word and other word processors have templates. The issue is they are not of a common standard or markup.
You can also use HTML to render stuff in a common markup but it will not be very printer friendly.
from a c++ program i need to print a simple label. the label contains a text, an image and a barcode.(in my project the label is more complex, this is just for example)
my customer need a way to customize che label layout.
in the past in java I solve this problem using a report created with jasperreport. my customer customize the report with ireport and then i fill the data with an hashtable datasource (i never connect to an sql database)
anybody know a way to obtain something like this in java
really sorry for my scholastic english
Offhand, it's a bit hard to say -- most report generators assume some sort of database (SQL or at least accessible via ODBC) as the data source. I'd probably look into some that are free and include source code so you can change the data source (though I've no idea how difficult a modification that will be).
The other problem is that printing anything but plain text is somewhat non-portable; you'll need different code for Linux, Mac/OS or Windows. For Windows, one possibility would be Report Generator from CodeProject.com. If you want something more portable, you could use something like Xport to create XHTML output to be viewed in/printed from a browser (or any number of other programs that understand [X]HTML (there's also a commercial version). Of course, you could generate output in any number of other formats that support graphics, such as Postscript/PDF, LaTex, etc. This lets you use portable code to generate the report, but usually requires some non-portable code to invoke a viewer.
Last night before going to bed, I browsed through the Scalar Data section of Learning Perl again and came across the following sentence:
the ability to have any character in a string means you can create, scan, and manipulate raw binary data as strings.
An idea immediately hit me that I could actually let Perl scan the pictures that I have stored on my hard disk to check if they contain the string Adobe. It seems by doing so, I can tell which of them have been photoshopped. So I tried to implement the idea and came up with the following code:
#!perl
use autodie;
use strict;
use warnings;
{
local $/="\n\n";
my $dir = 'f:/TestPix/';
my #pix = glob "$dir/*";
foreach my $file (#pix) {
open my $pic,'<', "$file";
while(<$pic>) {
if (/Adobe/) {
print "$file\n";
}
}
}
}
Excitingly, the code seems to be really working and it does the job of filtering out the pictures that have been photoshopped. But problem is many pictures are edited by other utilities. I think I'm kind of stuck there. Do we have some simple but universal method to tell if a digital picture has been edited or not, something like
if (!= /the origianl format/) {...}
Or do we simply have to add more conditions? like
if (/Adobe/|/ACDSee/|/some other picture editors/)
Any ideas on this? Or am I oversimplifying due to my miserably limited programming knowledge?
Thanks, as always, for any guidance.
Your best bet in Perl is probably ExifTool. This gives you access to whatever non-image information is embedded into the image. However, as other people said, it's possible to strip this information out, of course.
I'm not going to say there is absolutely no way to detect alterations in an image, but the problem is extremely difficult.
The only person I know of who claims to have an answer is Dr. Neal Krawetz, who claims that digitally altered parts of an image will have different compression error rates from the original portions. He claims that re-saving a JPEG at different quality levels will highlight these differences.
I have not found this to be the case, in my investigations, but perhaps you might have better results.
No. There is no functional distinction between a perfectly edited image, and one which was the way it is from the start - it's all just a bag of pixels in the end, after all, and any other metadata you can remove or forge all you want.
The name of the graphics program used to edit the image is not part of the image data itself but of something called meta data - which may be stored in the image file but, as others have noted, is neither required (so some programs may not store it, some may allow you an option of not storing it) nor reliable - if you forged an image, you might have forged the meta data as well.
So the answer to your question is "no, there's no way to universally tell if the pic was edited or not, although some image editing software may write its signature into the image file and it'll be left there by carelessness of the editing person.
If you're inclined to learn more about image processing in Perl, you could take a look at some of the excellent modules CPAN has to offer:
Image::Magick - read, manipulate and write of a large number of image file formats
GD - create colour drawings using a large number of graphics primitives, and emit the drawings in various formats.
GD::Graph - create charts
GD::Graph3d - create 3D Graphs with GD and GD::Graph
However, there are other utilities available for identifying various image formats. It's more of a question for Super User, but for various unix distros you can use file to identify many different types of files, and for MacOSX, Graphic Converter has never let me down. (It was even able to open the bizarre multi-file X-ray of my cat's shattered pelvis that I got on a disc from the vet.)
How would you know what the original format was? I'm pretty sure there's no guaranteed way to tell if an image has been modified.
I can just open the file (with my favourite programming language and filesystem API) and just write whatever I want into that file willy-nilly. As long as I don't screw something up with the file format, you'd never know it happened.
Heck, I could print the image out and then scan it back in; how would you tell it from an original?
As other's have stated, there is no way to know if the image was doctored. I'm guessing what you basically want to know is the difference between a realistic photograph and one that has been enhanced or modified.
There's always the option of running some extremely complex image recognition algorithm that would analyze every pixel in your image and do some very complicated stuff to determine if the image was doctored or not. This solution would probably involve AI which would examine millions of photos that are both doctored and those that are not and learn from them. However, this is more of a theoretical solution and isn't very practical... you would probably only see it in movies. It would be extremely complex to develop and probably take years. And even if you did get something like this to work, it probably still wouldn't be 100% correct all the time. I'm guessing AI technology still isn't at that level and could take a while until it is.
A not-commonly-known feature of exiftool allows you to recognize the originating software through an analysis of the JPEG quantization tables (not relying on image metadata). It recognizes tables written by many applications. Note that some cameras may use the same quantization tables as some applications, so this isn't a 100% solution, but it is worth looking into. Here is an example of exiftool run on two images, the first was edited by photoshop.
> exiftool -jpegdigest a.jpg b.jpg
======== a.jpg
JPEG Digest : Adobe Photoshop, Quality 10
======== b.jpg
JPEG Digest : Canon EOS 30D/40D/50D/300D, Normal
2 image files read
This will work even if the metadata has been removed.
There is existing software out there which uses various techniques (compression artifacting, comparison to signature profiles in a database of cameras, etc.) to analyze the actual image data for evidence of alteration. If you have access to such software and the software available to you provides an API for external access to these analysis functions, then there's a decent chance that a Perl module exists which will interface with that API and, if no such module exists, it could probably be created rather quickly.
In theory, it would also be possible to implement the image analysis code directly in native Perl, but I'm not aware of anyone having done so and I expect that you'd be better off writing something that low-level and processor-intensive in a fully-compiled language (e.g., C/C++) rather than in Perl.
http://www.impulseadventure.com/photo/jpeg-snoop.html
is a tool that does the job almost good
If there has been any cloning , there is a variation in the pixel density..or concentration which sometimes shows up.. upon manual inspection
a Photoshop cloned area will have even pixel density(my meaning is variation of Pixels wrt a scanned image)