I have a generated report in Informix 4GL that prints to the screen.
I need to have one column displayed in reverse format.
I tried the following:
print line_image attribute(reverse)
But that doesn't work. Is this possible at all?
Adding on to the previous answer, you can try the following
print "\033[7mHello \033[0mWorld"
\033[7m means to print in reverse. And, \033[0m means to go back to standard.
If you mean "is there any way at all to do it", the answer's "yes". If you mean "is there a nice easy built-in way to do it", the answer's "no".
What you'll need to do is:
Determine the character sequence that switches to 'reverse' video — store the characters in a string variable brv (begin reverse video; choose your own name if you don't like mine).
Determine the character sequence that switches to 'normal' video — store the characters in a string variable erv (end reverse video).
Arrange for your printing to use:
PRINT COLUMN 1, first_lot_of_data,
COLUMN 37, brv, reverse_data,
COLUMN 52, erv,
COLUMN 56, next_lot_of_data
There'll probably be 3 or 4 characters needed to switch. Those characters will be counted by the column-counting code in the report.
Different terminal types will have different sequences. These days, the chances are your not dealing with the huge variety of actual green-screen terminals that were prevalent in the mid-80s, so you may be able to hardwire your findings for the brv and erv strings. OTOH, you may have to do some fancy footwork to find the correct sequences for different terminals at runtime. Shout if you need more information on this.
A simple way which might allow you to discover the relevant sequences is to run a program such as (this hasn't been anywhere near an I4GL compiler — there are probably syntax errors in it):
MAIN
DISPLAY "HI" AT 1,1
DISPLAY "REVERSE" AT 1,4 ATTRIBUTE(REVERSE)
DISPLAY "LO" AT 1, 12
SLEEP 2
END MAIN
Compile that into terminfo.4ge and run:
./terminfo.4ge # So you know what the screen looks like
./terminfo.4ge > out.file
There's a chance that won't use the display attributes. You'd see that if you run cat out.file and don't see the reverse flash up, then we have to work harder.
You could also look at the terminal entry in the termcap file or from the terminfo entry. Use infocmp $TERM (with the correct terminal type set in the environment variable) and look for the smso (enter standout mode) and rmso (exit standout mode) capabilities. Decipher those (I have rmso=\E[27m and smso=\E[7m for an xterm-256color terminal; the \E is ASCII ESC or \033) and use them in the brv and erv strings. Note that rmso is 5 characters long.
Related
I'm playing around with ANSI escape sequences, e.g.
echo -e "\e[91mHello\e[m"
on a Linux console to display colored text.
Now I try to use superscript and subscript output like a=b².
I read here and here about: Partial Line Down (subscript) and Partial Line Up (superscript) but I'm not sure about the exact syntax and even which terminal client might supports this.
Any suggestions about this?
Possibly some commercial product supports it, but it's not supported by any terminal emulator you'll encounter (unless someone modifies one just to prove a point).
The standard describes possible escape sequences, but there is no requirement that any given sequence is supported by any terminal. There are commonly supported (and assumed) sequences such as clearing the screen, but even for that, not all terminals have supported the feature.
The reason is that terminal emulators are generally used with applications (such as text editors) which assume a regular set of rows/columns, and that the text is shown compactly (no extra space such as would be needed to allow for partial line movement. Back in the day when people used typewriters, it was common to have 1.5 or 2.0 line-spacing, and get no more than 33 lines on a page. That changed, long ago.
The need for subscripts/superscripts didn't go away — Unicode provides a usable set of characters with that representation (see Superscripts and Subscripts
Range: 2070–209F)
Further reading:
Your New Royal Portable (1953).
Line Spacing - Butterick's Practical Typography
console_codes - Linux console escape and control sequences
I am facing a weird problem.
I have extracted data from an Excel file. It should contain an IBAN account number.
Then I tried to analyze the set of account numbers (which the source guarantees to be good) with a Java library.
To keep the scope of the question narrow, I can't explain the following. The below strings are different
03069
03069
The first is a copy & paste from the Excel file, the second is handwritten. Google returns different results for abi [above number] and in fact in the second case I can find that it is the bank code for Intesa Sanpaolo bank (exact page displaying the ABI code, localized, here).
So, to keep the scope narrow: how is that possible? Is it something to do with the encoding?
Try it yourself: do CTRL+F and try type "030", it will select both lines. Now type 6, it will match only the 2nd line.
Same happened in Notepad++
There's an U+200B ZERO WIDTH SPACE in between 030 and 69 in the first text.
Paste the text in https://www.branah.com/unicode-converter for example, or edit in a hexadecimal capable editor.
The solution for cleaning such strings could be for example to whitelist characters, so replace everything that isn't A-Z0-9 will be scrubbed.
I have a string that, by using string.format("%02X", char), I've received the following:
74657874000000EDD37001000300
In the end, I'd like that string to look like the following:
t e x t NUL NUL NUL í Ó p SOH NUL ETX NUL (spaces are there just for clarification of characters desired in example).
I've tried to use \x..(hex#), string.char(0x..(hex#)) (where (hex#) is alphanumeric representation of my desired character) and I am still having issues with getting the result I'm looking for. After reading another thread about this topic: what is the way to represent a unichar in lua and the links provided in the answers, I am not fully understanding what I need to do in my final code that is acceptable for this to work.
I'm looking for some help in better understanding an approach that would help me to achieve my desired result provided below.
ETA:
Well I thought that I had fixed it with the following code:
function hexToAscii(input)
local convString = ""
for char in input:gmatch("(..)") do
convString = convString..(string.char("0x"..char))
end
return convString
end
It appeared to work, but didnt think about characters above 127. Rookie mistake. Now I'm unsure how I can get the additional characters up to 256 display their ASCII values.
I did the following to check since I couldn't truly "see" them in the file.
function asciiSub(input)
input = input:gsub(string.char(0x00), "<NUL>") -- suggested by a coworker
print(input)
end
I did a few gsub strings to substitute in other characters and my file comes back with the replacement strings. But when I ran into characters in the extended ASCII table, it got all forgotten.
Can anyone assist me in understanding a fix or new approach to this problem? As I've stated before, I read other topics on this and am still confused as to the best approach towards this issue.
The simple way to transform a base16-encoded string is just to
function unhex( input )
return (input:gsub( "..", function(c)
return string.char( tonumber( c, 16 ) )
end))
end
This is basically what you have, just a bit cleaner. (There's no need to say "(..)", ".." is enough – if you specify no captures, you'll automatically get the whole match. And while it might work if you write string.char( "0x"..c ), it's just evil – you concatenate lots of strings and then trigger the automatic conversion to numbers. Much better to just specify the base when explicitly converting.)
The resulting string should be exactly what went into the hex-dumper, no matter the encoding.
If you cannot correctly display the result, your viewer will also be unable to display the original input. If you used different viewers for the original input and the resulting output (e.g. a text editor and a terminal), try writing the output to a file instead and looking at it with the same viewer you used for the original input, then the two should be exactly the same.
Getting viewers that assume different encodings (e.g. one of the "old" 8-bit code pages or one of the many versions of Unicode) to display the same thing will require conversion between different formats, which tends to be quite complicated or even impossible. As you did not mention what encodings are involved (nor any other information like OS or programs used that might hint at the likely encodings), this could be just about anything, so it's impossible to say anything more specific on that.
You actually have a couple of problems:
First, make sure you know the meaning of the term character encoding, and that you know the difference between characters and bytes. A popular post on the topic is The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)
Then, what encoding was used for the bytes you just received? You need to know this, otherwise you don't know what byte 234 means. For example it could be ISO-8859-1, in which case it is U+00EA, the character ê.
The characters 0 to 31 are control characters (eg. 0 is NUL). Use a lookup table for these.
Then, displaying the characters on the terminal is the hard part. There is no platform-independent way to display ê on the terminal. It may well be impossible with the standard print function. If you can't figure this step out you can search for a question dealing specifically with how to print Unicode text from Lua.
Is it possible to have a TeX command which will take the whole next word (or the next letters up to but not including the next punctuation symbol) as an argument and not only the next letter or {} group?
I’d like to have a \caps command on certain acronyms but don’t want to type curly brackets over and over.
First of all create your command, for example
\def\capsimpl#1{{\sc #1}}% Your main macro
The solution to catch a space or punctuation:
\catcode`\#=11
\def\addtopunct#1{\expandafter\let\csname punct#\meaning#1\endcsname\let}
\addtopunct{ }
\addtopunct{.} \addtopunct{,} \addtopunct{?}
\addtopunct{!} \addtopunct{;} \addtopunct{:}
\newtoks\capsarg
\def\caps{\capsarg{}\futurelet\punctlet\capsx}
\def\capsx{\expandafter\ifx\csname punct#\meaning\punctlet\endcsname\let
\expandafter\capsend
\else \expandafter\continuecaps\fi}
\def\capsend{\expandafter\capsimpl\expandafter{\the\capsarg}}
\def\continuecaps#1{\capsarg=\expandafter{\the\capsarg#1}\futurelet\punctlet\capsx}
\catcode`\#=12
#Debilski - I wrote something similar to your active * code for the acronyms in my thesis. I activated < and then \def<#1> to print the acronym, as well as the expansion if it's the first time it's encountered. I also went a bit off the deep end by allowing defining the expansions in-line and using the .aux files to send the expansions "back in time" if they're used before they're declared, or to report errors if an acronym is never declared.
Overall, it seemed like it would be a good idea at the time - I rarely needed < to be catcode 12 in my actual text (since all my macros were in a separate .sty file), and I made it behave in math mode, so I couldn't foresee any difficulties. But boy was it brittle... I don't know how many times I accidentally broke my build by changing something seemingly unrelated. So all that to say, be very careful activating characters that are even remotely commonly-used.
On the other hand, with XeTeX and higher unicode characters, it's probably a lot safer, and there are generally easy ways to type these extra characters, such as making a multi (or compose) key (I usually map either numlock or one of the windows keys to this), so that e.g. multi-!-! produces ¡). Or if you're running in emacs, you can use C-\ to switch into TeX input mode briefly to insert unicode by typing the TeX command for it (though this is a pain for actually typing TeX documents, since it intercepts your actual \'s, and please please don't try defining your own escape character!)
Regarding whitespace after commands: see package xspace, and TeX FAQ item Commands gobble following space.
Now why this is very difficult: as you noted yourself, things like that can only be done by changing catcodes, it seems. Catcodes are assigned to characters when TeX reads them, and TeX reads one line at a time, so you can not do anything with other spaces on the same line, IMHO. There might be a way around this, but I do not see it.
Dangerous code below!
This code will do what you want only at the end of the line, so if what you want is more "fluent" typing without brackets, but you are willing to hit 'return' after each acronym (and not run any auto-indent later), you can use this:
\def\caps{\begingroup\catcode`^^20 =11\mcaps}
\def\mcaps#1{\def\next##1 {\sc #1##1\catcode`^^20 =10\endgroup\ }\next}
One solution might be setting another character as active and using this one for escaping. This does not remove the need for a closing character but avoids typing the \caps macro, thus making it overall easier to type.
Therefore under very special circumstances, the following works.
\catcode`\*=\active
\def*#1*{\textsc{\MakeTextLowercase{#1}}}
Now follows an *Acronym*.
Unfortunately, this makes uses of \section*{} impossible without additional macro definitions.
In Xetex, it seems to be possible to exploit unicode characters for this, so one could define
\catcode`\•=\active
\def•#1•{\textsc{\MakeTextLowercase{#1}}}
Now follows an •Acronym•.
Which should reduce the effects on other commands but of course needs to have the character ‘•’ mapped to the keyboard somewhere to be of use.
Are there any conventions for formatting console output from a command line app for readability and consistency? For instance, do you indent sub-information, when do you print a blank line, if ever, how should you accent important statements.
I've found output can quickly degenerate into a chaotic blur. I'm interested in hearing about what other people do.
Update: Really this is for embedded software which spits debug status out a terminal, but it's pretty much like a console app, and I figured everyone would be more familiar with that. Thanks so far.
I'd differentiate two kinds of programs:
Do you print information that might be used by a script (i.e. it should be parseable)? Then define a pretty strict format and use only that (for example fixed field separators).
Do you print information that need not be parsed by a script (or is there an alternative script-parseable format already)? Then write what comes natural:
My suggestions:
write it so that you would like to read it
indent sub-information 2 or 4 spaces, definitely not more
separate blocks of information by one empty line at most
respect the COLUMN environment variable (and possible ROWS if it applies to your output).
If this is for a *nix environment, then I'd recommend reading Basics of Unix Philosophy. It's not specific to output but there are some good guidelines for command line programs in general.
Expect the output of every program to become the input to another, as yet unknown, program. Don't clutter output with extraneous information. Avoid stringently columnar or binary input formats. Don't insist on interactive input.