LEFTY(1)

💖 LEFTY(1) — the girlies' guide to a Programmable Graphics Editor 💖

okay so bestie, welcome to the General Commands Manual glow-up of lefty. this is the moment. let's go. 🦋

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✨ NAME ✨

lefty — A Programmable Graphics Editor. yes that's the whole name. iconic, concise, ate. 💅

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🌸 SYNOPSIS 🌸

lefty [ options ] [ file ]

that's it. that's the vibe. options optional, file optional, slay mandatory. ✨

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🎀 DESCRIPTION 🎀

so lefty is a two-view graphics editor for technical pictures, and the way it does it is genuinely main character energy. 💜

here's the thing: this editor has no hardwired knowledge about specific picture layouts or editing operations. like, zero. none. it's not out here assuming things. instead, every single picture is described by a program — and that program contains:

• functions to draw the picture 🎨
• functions to perform editing operations that are appropriate for that specific picture ✂️

and it doesn't stop there, no ma'am. primitive user actions — like mouse and keyboard events — are also bound to functions in this program. so the program is running the whole show. 🫶

besides the graphical view of the picture itself, the editor presents a textual view of the program that describes the picture. two views. two screens. one legend. 👑

so why does this matter? programmability + the two-view interface allow the editor to handle a variety of pictures, but they're particularly useful for pictures used in technical contexts, e.g. graphs and trees. 📊🌳

also — and this is lowkey the coolest part — lefty can communicate with other processes. this feature allows it to:

• use existing tools to compute specific picture layouts 🔧
• let external processes use the editor as a front end to display their data structures graphically 🌈

it's giving collaborative. it's giving modular. it's giving yes and. 💀✨

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💫 USAGE 💫

okay so housekeeping, bestie. the file name is optional. it may be -, which means reading from standard input. classic. 📥

lefty uses two environment variables: LEFTYPATH and LEFTYOPTIONS.

• LEFTYPATH — a colon separated list of directories. when lefty tries to open a file, it searches that path for the file. when lefty tries to start up another process, it searches LEFTYPATH first, then the standard PATH variable. 🗺️
• LEFTYOPTIONS — can be used to set specific options. ✨

⚠️ important: options specified on the command line override options set through this variable. command line stays winning. 💅

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🌟 OPTIONS 🌟

one bullet per option, no skips, we respect the whole menu. 🍓

• -x — instructs the editor to exit after processing file. bye bestie, you did great. 👋
• -e <expression> — <expression> is parsed and executed. go off. 🔥
• -el <num> — set the error reporting level. the default value is 0.
  • 0 — never prints any messages. 🤐
  • 1 — prints severe errors, such as trying to return from a non function. 🚨
  • 2 — the most useful: it reports function calls that cannot be executed, either because there is no function, or because of argument mismatches. 👑
  • 3 — also warns about bad variable names. 🏷️
  • 4,5 — warn about expressions that do not return a value. 🫥
  • > only level 1 messages are real errors. the rest arise from legal lefty statements, but may be caused by some logic errors. so like… valid syntax, questionable choices. 🙈
• -sd <num> — specifies how much of the stack to show, when an error message is to be printed. the default value is 2.
  • 0 — no part of the stack is shown.
  • 1 — only the top stack frame is printed.
  • 2 — the full stack is printed. the whole saga. 📚
• -sb <num> — specifies how much of each function in the stack to show, when an error message is to be printed. the default value is 2.
  • 0 — no part of the function is shown.
  • 1 — only the line around the error is printed.
  • 2 — the full function body is printed. spill the whole thing. 🗣️
• -df <string> — sets the default font. this font is used whenever a requested font cannot be found. the string must be a legal X font. if string is '', lefty will draw small boxes instead of text. 📦 (boxes. as text. a moment of silence.)
• -ps <file> — specifies a default file name for postscript files. this name is used when no name is specified in the createwidget call. the default file name is out.ps. 🖨️
• -V — prints the version. 🏷️
• -? — prints the usage and exits. 🆘

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👀 SEE ALSO 👀

• lefty user guide. 📖

iykyk. go read it, bestie, it's the director's cut. 🎬

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and that's the whole page, fr fr — from the General Commands Manual, no cap, and yes the title line at the bottom just says LEFTY(1) because that's how manpages do. same energy top and bottom. periodt. 💅✨🦋🎀