pic

troff preprocessor for drawing diagrams

TLDR

Process pic to troff

$ pic [diagram.pic] | troff

Generate output

$ pic [diagram.pic] > [output.troff]

Safe mode

$ pic -S [diagram.pic]

Check syntax only

$ pic -n [diagram.pic]

Show version

$ pic --version

SYNOPSIS

pic [-S] [-n] [-C] [options] [files]

pic is a troff preprocessor for drawing diagrams. It converts textual descriptions into troff drawing commands.
Diagrams use geometric primitives: boxes, circles, lines, arrows. Positioning is relative or absolute.
Objects connect with lines and arrows. Labels and text annotate elements.
The language supports macros and variables. Complex diagrams build from reusable components.
Output integrates with groff/troff document processing. Pic diagrams embed in technical documents.

PARAMETERS

-S

Safe mode (no shell commands).

-n

Suppress output, check syntax.

-C

Compatible mode.

-D

Define macro.

-T DEVICE

Output device.

-z

GNU extensions.

EXAMPLE

$ .PS
box "Start"
arrow
circle "Process"
arrow
box "End"
.PE

CAVEATS

Limited compared to modern diagramming tools. Troff output only. Steep learning curve.

HISTORY

pic was created by Brian Kernighan at Bell Labs in the 1980s. It was part of the troff/groff document preparation system and influenced later diagramming languages.

pic