I am working on an AWK script that processes a text file line by line, formats them and stuffs them into an SVG file text field. The SVG takes care of text wrapping automatically, but I want to predict where each line will wrap. (I need some characters to repeat and extend close to the end of the line). I know the exact font, font size, and width of the text field.
Is there a standard utility in Linux or easily available in Ubuntu that will give a width in pixels or inches given a string, font, and font size?
For example:
get-width 'Nimbus Sans L' 18 "test string"
returns "x pixels"
You can do this with the ghostscript interpreter, assuming you have that and the fonts are set up correctly.
Here is the possibly mysterious incantation:
gs -dQUIET -sDEVICE=nullpage 2>/dev/null - \
<<<'18 /NimbusSanL-Regu findfont exch scalefont setfont
(test string) stringwidth pop =='
Using -dQUIET suppresses warnings about font substitution, which is probably not a good idea until you have some idea about how to name the fonts you're looking for.
ghostscript is not a layout engine, and you may find the measurement doesn't work with complicated bidirectional text, combining characters, or East Asian languages. (I tested it with a little Arabic, and it was OK, but no guarantees.) It does not kern, so it will normally produce measurements a little larger than a good layout engine, and possibly a lot larger if the font positions diacritics using kerning.
Finally, if your text includes unbalanced parentheses or backslashes, you'll need to escape them. I use the following:
"$(sed 's/[()\\]/\\&/g' <<<"$text")"
That's because Postscript strings are enclosed in (...) -- (test string) -- and are allowed to include balanced parentheses. Unbalanced parentheses will usually generate a syntax error, unless they are backslash-escaped.
If you have access to inkscape:
FONT="Nimbus Sans L"
SIZE=18
STRING="test string"
inkscape --without-gui --query-id=id1 -W <(echo '<svg><text id="id1" style="font-size:'$SIZE'px;font-family:'$FONT';">'$STRING'</text></svg>') 2>/dev/null
Output (e.g.):
76.577344
Related
I have a PostScript file with image and text. I want to print it to a laser printer so that the images print in a halftone round pattern.
I am trying to print it from the command line. I would prefer a PDF output first and then I'll print to the laser printer.
I have an HP Laserjet P2015 printer installed in Windows 10.
gswin64c.exe -dQUIET -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=output.pdf test.ps -c "<< /HalftoneType 1 /Frequency 37 /Angle 45 /SpotFunction {180 mul cos exch 180 mul cos add 2 div} >> sethalftone"
The PDF file is generated. However, the images does not appear to be in Round Halftone format. I see no change in the image.
This is the original Image
I want the printout to look like this: Required output
For some reason the output is the same as the original.
pdfwrite doesn't create monochrome output, so no, the output won't be halftoned. The whole point of the pdfwrite device is to maintain the output as close in quality as possible to the input.
There is no way to get monochrome output from pdfwrite unless the monochrome is in the input.
If you instead use a monochrome output device (e.g., tiffg3 or tiffg4) you should see a difference, unless the input file (which you haven't supplied) also sets a screen, in which case the last one encountered will take effect. That is, if the PostScript input file specifies a halftone screen, that's the one that will get used.
What you are asking for is what I might generally describe as a hard problem, probably much harder than you expect.
Your best bet is to send the PostScript directly to the printer, since it supports PostScript.
Problem 1; your PostScript file may already contain a halftone in it which overrides the one you want to use. You can usually prevent that by redefining the sethalftone and setscreen operators:
/sethalftone {pop} bind def
/setscreen {pop pop pop} bind def
You do that after you'[ve defined your own halftone, obviously. Or you can just edit the PostScript file and remove the halftone definition, its usually not that hard to find.
Problem 2 is that printer manufacturers sometimes 'tweak' the interpreter to always use their preferred halftone and prevent you overriding it in PostScript. The only way to find out if that's happening is to try a quick test; print a simple image with the default screen, then set a really coarse screen, say 10 lpi and print the same image. If there's no difference then you know that's not a viable option. If there is, then you can just set the screen you want.
Now, if the printer won't let you change the halftone then the only solution is to render the PostScript to an image using Ghostscript (which will let you change the halftone) and then send the resulting image to the printer. You will need to use a 1 bpp device, something like tiffg3 or tiffg4 should work fine.
The problem here is that you need to ensure that the image fits on the media of the printer, because if it doesn't then the likelihood is that the printer will slightly scale down the image so that it does fit, thereby squashing the halftone cells.
Even more subtly, the printable area of the media in the printer may not be the same as the size of the media. Paper handling can mean that there are some areas of the paper that can't be printed on, and the variability in the feeding of the paper can mean that the printer will refuse to print right to the edges anyway. Because if it did, and there was, say, a 1 mm deviation in the paper handling, then 1 mm of the edge would 'fall off' and there would be a 1 mm white gap at the other edge...
I use simple GDI DrawText to output blocks of text to a printer.
The font used in the sample is Segoe UI. But you can use Arial or others too. It doesn't matter.
The algorithm for large text blocks is simple. DrawText is called with DT_CALCRECT with a kind of binary search for the length to get the largest possible text to print. Than DrawText is called without DT_CALCRECT to print the block.
Simple one line text column text is written with one call to DrawText with the given coordinates of the rectangle.
The result is real strange and can be seen in this sample PDF.
Just look on the first line after the header. You can see the text "Test, Test" and you can see the strange kerning here perfectly. The kerning os sometimes so bad, that you can't even read the words.
How to get around this? Is it a problem with the used printer? Is it a problem with DrawText?
The distance between some chars in a word seem to be random in some case. Some spacing are wide other to narrow. The letter combination looks strange unreadable and ugly.
I tried different fonts and printers but the problem just varies but it is always present.
I know about ExTextOut and the capabilities to define the distance/kerning between all chars, but frankly I don't want to care about this. I just want that DrawText behaves on the printer like on the screen. The stuff works on the screen perfectly.
Added 2018-08-23 08:49 GMT+2*
To the code (it is a complex printing engine).
1.Fonts to print are created simply with CFont::CreatePointFont, so the LOGFONT structure is cleared to zero and no additional flags are used except point and face.
2.The mapping mode is MM_ANISOTROPIC. To scale what is seen on the screen and what is to be printed I just use the size of a komparable object (textblock) on the printer and the same size on the screen. The real values for the sample printout to the Microsoft PDF Printer are as follows, the real way I calculate them is not of interest:
m_pDC->SetMapMode(MM_ANISOTROPIC);
m_pDC->SetViewportExt(2363,100);
m_pDC->SetWindowExt(355,13);
This has the effect that the height of a line in LPs is 13, the average character width in LPs is 6...
I'm using the output of the excellent package icdiff (https://github.com/jeffkaufman/icdiff) to check for differences between updated iterations of files. I'd like to parse out just the significant differences though. From the package --help I can't see any in-built options (and for full disclosure I've 'cross posted' at the github issues page to see if it can be added or I've missed something).
This has got me wondering whether a hacky solution might be to parse out the lines by their colour, since they are also colour coded by 'severity of difference'. Is this at all possible in bash? (Alternative approaches are welcome too!)
Here's a sample of the output (I can only think to add a picture here since the markup wouldnt show colour). I'd like to get just the lines where the whole line is solid red/green for instance. Excuse some of the screen wrapping, my monitor isn't wide enough and the text is small enough already.
with GNU Grep, for example
grep -Po $'\e\[31m\K.*(?=\e\[\d+m)'
to extract text in red,
\K to keep the left outside match, like a lookbehind
(?=..) lookahead assertion 0 length match
you can grep on the ANSI escape sequences, e.g. (with 31 for red):
grep '^[\[31m' # make the escape character (^[) by typing ctrl+v ESC
but you need to make sure your output stays colored if it is not sent to a terminal : (many programs will make their output B&W when output is not a terminal. - you can check it with less, which will show you the escape sequences)
Is there any way to change the size of the text in shell script ?
I mean dynamically during the execution .
For example I have an image drawn with ASCII code and i want to reduce the size of text .
Now when echo or cat the image it will be shown as the command prompt actual size (the actual font size) .
A couple of comments note that font size/style are under the control of the terminal emulator, and that xterm (and a few others) support escape sequences to change these.
However - almost all terminal emulators (all that you would be likely to encounter) rely upon keeping the characters in a nice row/column grid. All of the characters have the "same" size. If you change the size of the font in xterm, all of the characters on the screen change to the same size. So there is no way to (as OP asks) to reduce the font-size temporarily, e.g., while using ASCII graphics to draw a picture using aalib, etc.
If you want to do something like that, the easiest way to do it is to have the script run its graphics in a separate window, e.g., by splitting it up into one part that starts the window and another script to draw the graphics.
For an alternate via of terminals and fonts, there is always something like 9term (no rows, no columns, no vi).
'Hi, i would like to print the old DOS characters 176 to 178 (filled cursor with gradients), unicode 2591, 2592 and 2593, light, medium and dark shade in ruby on a windows console, how to do it please ?
tried this
p "\u2592" #=> "\u2592"
p [176].pack('U*') => °
Don't use p; use print (or puts if you want a trailing newline). p displays things using #inspect, which gives you something you can copy and paste into source code, including quotation marks, etc. print and puts are the normal way to output text.
Assuming you have your encodings set up right in your program and console, then print "\u2592" and similar should work fine. Although it can be tricky to set up a Windows console for Unicode, and you might want to look at some third-party console applications.