VLNA(1)

✨ VLNA(1) ✨

💖 NAME 💖

okay so meet vlna 🦋, the tiny program that adds a tilde after each non-syllabic preposition. it's giving typography queen energy 👑

🎀 USAGE 🎀

vlna [options] [filenames]

🌸 PREFACE 🌸

okay bestie, there's a special Czech and Slovak typography rule 🇨🇿 you are NOT allowed to leave a non-syllabic preposition hanging at the end of a line and then keep writing on the next one 💀. so "v lese" (in a forest) can't be split like "v<new-line>lese". it's a whole no-no 🙅‍♀️

that's where vlna slides in ✨. it adds an asciitilde between the preposition and the next word and removes the space(s) in that spot, so "v lese" becomes "v~lese". obsessed 😭. you can even run it as a preprocessor before TeXing 🧚. and if you don't love the tilde, you can store a different sequence instead with the -x option (see below) 💅.

💅 DESCRIPTION 💅

so the program vlna processes one or more files 📂, hunts down the non-syllabic prepositions that are followed by space(s), and turns those space(s) into an asciitilde every single time ✨.

inside the file, you can pause the whole thing with the %~- sequence and bring it back with %~+ 🎀. these sequences can have spaces in them too, so % ~- is a valid sequence as well, iykyk 🙈.

here's how it decides something is a preposition 🔍. you can write any number of opening parentheses before the preposition, and before those (optional) parentheses there has to be a space, a tabelator, or a new-line. the preposition itself is a one-letter word, and the letter has to come from this set: {KkSsVvZzOoUuAI}. if you want to change that set, check out the -v option 🦋. starting from version 1.2, a TeX sequence can also sit in front of the preposition and before the brace 🌈. for example, "<new-line>([V lese" becomes "<new-line>([V~lese" 💖. and "\uv{V lese}" becomes "\uv{V~lese}" 🫶.

at least one blank-space has to come after the preposition before the next word 🍓. a blank-space is a space or a tabelator, and one <new-line> can sneak in there too 🙈. all of those characters get removed and replaced with asciitilde (or whatever string you picked with -x) ✨. if a <new-line> gets deleted, a fresh <new-line> is created before the preposition (and before the optional parentheses) so the number of lines stays exactly the same 📏. for example, "... V<new-line><tabelator>lese" becomes "...<new-line>V~lese" 🌷.

the program also checks that TeX's math environments are consistent (unless you use -m) 🧮. for example, the "$...$$...$" sequence, which means switching into display mode inside text-math mode, throws a warning 😭. an empty line inside display mode also throws a warning, and then the program handles the next text like normal non-math mode 💀. a "$" inside display mode is totally accepted though, because stuff like $$..\hbox{..$..$}..$$ is allowed and super common 💜.

verbatim mode gets checked too 🔍. if the file ends while verbatim mode is still open, you get a warning 🚨. you can switch this off with -n or -w 🙅‍♀️.

and the program won't touch letters that look like prepositions but aren't, when a TeX or LaTeX sequence comes right before them 💅. for example, "vlastnosti \TeX u jsou" is NOT converted to "vlastnosti \TeX u~jsou", because after TeX processing it prints as "vlastnosti TeXu jsou". the "u" is a suffix there, not a preposition 🌸.

🎀 OPTIONS 🎀

the options are, like, totally optional 🫶, and you can write them in any order you want, separated by spaces ✨.

• -f — filter mode 🧚. the [filenames] get treated like this:

vlna -f filename1 filename2
    Input is filename1, output is filename2.

vlna -f filename1
    Input is filename1, output is stdout.

vlna -f
    Input is stdin, output is stdout.

vlna filename1 [filename2 [filename3 ...]]
    If the -f option is omitted then each file is processed
    independently and it is re-written.

• -s — silent mode 🤫. no messages, warnings, or statistics get printed. only the errors that crash the program early still show up 💀. if you leave this out, the banner, warnings, and statistics all go to stderr 📣.
• -r — no backups 🙅‍♀️. this one doesn't matter if you're using -f. if you use neither -f nor -r, each rewritten file gets its original contents saved to a backup file. the backup name is the same as the filename, except the last character is swapped for a tilde 🎀.
• -v characters — choose your own preposition letters 🔤. the set of characters that count as non-syllabic prepositions is set here. default: -v KkSsVvZzOoUuAI. there has to be a space between -v and the characters 💖.
• -x code — swap out the tilde 🌈. the code is a hexadecimal string, and you need every hex digit, no skipping 🙈. this string gets saved after prepositions instead of the default asciitilde. for example, -x C2A0 stores two bytes after each non-syllabic preposition: the first is C2 and the second is A0, which means a NO-BREAK SPACE in UTF8 encoding ✨. another one: -x 00A0 gives you the NO-BREAK SPACE in UTF16 🧁. and -x 48454C4C4F gives you the string HELLO 👋. you need a space between -x and the code 🫶.
• -m — ignore math modes 🧮. $...$ and $$...$$ get ignored, so prepositions get searched for in math mode too. default (without -m): math modes are left alone, because (for example) "v" is a variable in math mode, not a preposition 🙅‍♀️.
• -n — ignore verbatim mode 🧾. \verb<char>...<char> and \begtt...\endtt are ignored, so the program can change stuff inside verbatim environments. default (without -n): verbatim mode is left alone 💅.
• -l — LaTeX mode 📜. \begin{display}...\end{display} and \begin{equation}...\end{equation} count as display mode, and \begin{verbatim}...\end{verbatim} counts as verbatim mode 🌸.
• -w — web mode 🕸️ (Knuth's web, no www:-). these sequences count as verbatim: @<, @d...@*, @space, or @>|. so program code stays untouched in *.w or *.web files, and only the web comments get processed 💜.

🧚 EXAMPLES 🧚

vlna -m -n -s -r file

this behaves similarly to the old vlnka program 👵✨.

vlna *.tex

every file with the .tex suffix in the current directory gets processed, and might get changed 📂. (the "*" is a UNIX-shell feature, periodt 🐚).

vlna -f file > /dev/null

only the consistency checking of math and verbatim modes happens here. no changes are made 🙈.

💜 AUTHORS 💜

Petr Olsak <olsak@math.feld.cvut.cz>. the Man page (Czech original) and Makefile were created by Rulolf Cejka 🫶.

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bestie, that's the whole thing 💅✨ this man page was dated August 30 2022 🌷, and it's the VLNA(1) page, the General Commands Manual 📖. go be a main character with your prepositions 👑🦋