harakit/docs/npc.1

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.\" Copyright (c) 2023 DTB <trinity@trinity.moe>
.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
.\"
.\" This work is licensed under CC BY-SA 4.0. To see a copy of this license,
.\" visit <http://creativecommons.org/licenses/by-sa/4.0/>.
.TH npc 1
.SH NAME
npc \(en show non-printing characters
.SH SYNOPSIS
npc
.RB ( -eht )
.SH DESCRIPTION
Npc reads from standard input and writes to standard output, replacing non-
printing characters with printable equivalents. Control characters print as a
carat ('^') followed by the character '@' through '_' corresponding to the
character replaced (e.g. control-X becomes "^X"). The delete character (0x7F)
becomes "^?". Characters with the high bit set (>127) are printed as "M-"
followed by the graphical representation for the same character without the
high bit set.
.PP
The
.B -e
option prints a currency sign ('$') before each line ending.
.PP
The
.B -t
option prints tab characters as "^I" rather than a literal horizontal tab.
.SH DIAGNOSTICS
Npc prints a debug message and exits with the appropriate sysexits(3) error
code in the event of an error, otherwise it exits successfully.
.SH BUGS
Npc operates in single-byte chunks regardless of intended encoding.
.SH RATIONALE
POSIX currently lacks a way to display non-printing characters in the terminal
using a standard tool. A popular extension to cat(1p), the -v option, is the
bandage solution GNU and other software suites use.
This functionality should be a separate tool because its usefulness extends
beyond that of cat(1p).
.SH AUTHOR
Written by DTB <trinity@trinity.moe>.
.SH COPYRIGHT
Copyright © 2023 DTB. License AGPLv3+: GNU AGPL version 3 or later
<https://gnu.org/licenses/agpl.html>.
.SH SEE ALSO
cat(1), cat-v(1)
.I UNIX Style, or cat -v Considered Harmful
by Rob Pike