First commit

Signed-off-by: Mattias Andrée <m@maandree.se>

7 files changed, 412 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
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+++ b/.gitignore
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+*\#*
+*~
+*.o
+*.a
+*.t
+*.lo
+*.to
+*.su
+*.so
+*.so.*
+*.dll
+*.dylib
+*.gch
+*.gcov
+*.gcno
+*.gcda
+/sumart
diff --git a/LICENSE b/LICENSE
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+++ b/LICENSE
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+ISC License
+
+© 2026 Mattias Andrée <m@maandree.se>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/Makefile b/Makefile
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+++ b/Makefile
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+.POSIX:
+
+CONFIGFILE = config.mk
+include $(CONFIGFILE)
+
+OBJ =\
+	sumart.o
+
+HDR =
+
+all: sumart
+$(OBJ): $(HDR)
+
+.c.o:
+	$(CC) -c -o $@ $< $(CFLAGS) $(CPPFLAGS)
+
+sumart: $(OBJ)
+	$(CC) -o $@ $(OBJ) $(LDFLAGS)
+
+install: sumart
+	mkdir -p -- "$(DESTDIR)$(PREFIX)/bin"
+	mkdir -p -- "$(DESTDIR)$(MANPREFIX)/man1/"
+	cp -- sumart "$(DESTDIR)$(PREFIX)/bin/"
+	cp -- sumart.1 "$(DESTDIR)$(MANPREFIX)/man1/"
+
+uninstall:
+	-rm -f -- "$(DESTDIR)$(PREFIX)/bin/sumart"
+	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man1/sumart.1"
+
+clean:
+	-rm -f -- *.o *.a *.lo *.su *.so *.so.* *.gch *.gcov *.gcno *.gcda
+	-rm -f -- sumart
+
+.SUFFIXES:
+.SUFFIXES: .o .c
+
+.PHONY: all install uninstall clean
diff --git a/README b/README
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+++ b/README
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+NAME
+	sumart - Visualise a checksum
+
+SYNOPSIS
+	sumart [rows columns] [checksum]
+
+DESCRIPTION
+	The sumart utility creates a visualisation of a checksum
+	using symbols and colours in a grid.
+
+	If no checksum is specified, it is read from the standard
+	input.
+
+	Any symbol that is not a hexadecimal digit is silently
+	discarded from the checksum.
+
+OPTIONS
+	The sumart utility conforms to the Base Definitions volume of
+	POSIX.1-2024, Section 12.2, Utility Syntax Guidelines.
+
+	No options are supported.
+
+OPERANDS
+	The following operands are supported:
+
+	rows
+		The number of rows tall the visualisation should be.
+
+	colums
+		The number of columns wide the visualisation should be.
+
+	checksum
+		The checksum to visualise.
+
+EXIT STATUS
+	0      Successful completion.
+
+	1      An error occurred.
+
+SEE ALSO
+	None.
diff --git a/config.mk b/config.mk
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+++ b/config.mk
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+PREFIX    = /usr
+MANPREFIX = $(PREFIX)/share/man
+
+CC = c99
+
+CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700 -D_GNU_SOURCE
+CFLAGS   =
+LDFLAGS  = -lsimple
diff --git a/sumart.1 b/sumart.1
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+++ b/sumart.1
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+.TH SUMART 1 SUMART
+.SH NAME
+sumart \- Visualise a checksum
+
+.SH SYNOPSIS
+.B sumart
+.RI [ rows
+.IR columns ]
+.RI [ checksum ]
+
+.SH DESCRIPTION
+The
+.B sumart
+utility creates a visualisation of a checksum
+using symbols and colours in a grid.
+.PP
+If no
+.I checksum
+is specified, it is read from the standard input.
+.PP
+Any symbol that is not a hexadecimal digit
+is silently discarded from the checksum.
+
+.SH OPTIONS
+The
+.B sumart
+utility conforms to the Base Definitions volume of
+POSIX.1-2024,
+.IR "Section 12.2" ,
+.IR "Utility Syntax Guidelines" .
+.PP
+No options are supported.
+
+.SH OPERANDS
+The following operands are supported:
+.TP
+.I rows
+The number of rows tall the visualisation should be.
+.TP
+.I colums
+The number of columns wide the visualisation should be.
+.TP
+.I checksum
+The checksum to visualise.
+
+.SH STDIN
+The
+.B sumart
+utility reads the checksum from the standard input
+if no checksum is specified.
+
+.SH INPUT FILES
+None.
+
+.SH ENVIRONMENT VARIABLES
+No environment variables affect the execution of sumart.
+
+.SH STDOUT
+The
+.B sumart
+utility prints the visualisation to the
+standard output.
+
+.SH STDERR
+The standard error is only used for diagnostic messages.
+
+.SH OUTPUT FILES
+None.
+
+.SH EXIT STATUS
+.TP
+0
+Successful completion.
+.TP
+1
+An error occurred.
+
+.SH SEE ALSO
+None.
diff --git a/sumart.c b/sumart.c
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+++ b/sumart.c
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+/* See LICENSE file for copyright and license details. */
+#include <libsimple.h>
+#include <libsimple-arg.h>
+
+USAGE("[rows columns] [checksum]");
+
+#define BITS 2
+
+
+int
+main(int argc, char *argv[])
+{
+#if BITS == 5
+	static const ssize_t x_movements[1 << BITS] = {
+		-3, -2, -1, +1, +2, +3,
+		-3, -2, -1, +1, +2, +3,
+		-3, -2,         +2, +3,
+		-3, -2,         +2, +3,
+		-3, -2, -1, +1, +2, +3,
+		-3, -2, -1, +1, +2, +3,
+	};
+	static const ssize_t y_movements[1 << BITS] = {
+		-3, -3, -3, -3, -3, -3,
+		-2, -2, -2, -2, -2, -2,
+		-1, -1,         -1, -1,
+		+1, +1,         +1, +1,
+		+2, +2, +2, +2, +2, +2,
+		+3, +3, +3, +3, +3, +3,
+	};
+#elif BITS == 4
+	static const ssize_t x_movements[1 << BITS] = {
+		-2, -1, 0, 0, +1, +2,
+		-2, -1,       +1, +2,
+		-2, -1, 0, 0, +1, +2
+	};
+	static const ssize_t y_movements[1 << BITS] = {
+		-2, -1, -2, -1, -2, -1,
+		 0,  0,          0,  0,
+		+1, +2, +1, +2, +1, +2
+	};
+#elif BITS == 3
+	static const ssize_t x_movements[1 << BITS] = {
+		-1, 0, +1,
+		-1,    +1,
+		-1, 0, +1
+	};
+	static const ssize_t y_movements[1 << BITS] = {
+		-1, -1, -1,
+		 0,      0,
+		+1, +1, +1
+	};
+#elif BITS == 2
+# if 0
+	static const ssize_t x_movements[1 << BITS] = {
+		-1, +1,
+		-1, +1
+	};
+	static const ssize_t y_movements[1 << BITS] = {
+		-1, -1,
+		+1, +1
+	};
+# else
+	static const ssize_t x_movements[1 << BITS] = {
+		 0, -1,
+		+1,  0
+	};
+	static const ssize_t y_movements[1 << BITS] = {
+		-1,  0,
+		 0, +1
+	};
+# endif
+#endif
+
+	static const char *const symbols[] = {
+		":", ".", "+", "=",
+		"¤", "o", "*", "£",
+		"X", "%", "&", "B",
+		"@", "#", "/", "^"
+	};
+	static const char *const colours[] = {
+		"", "34;1", "33;1"
+	};
+
+	const char *checksum;
+	char *data = NULL, *end;
+	size_t size = 0u;
+	size_t len = 0u, cell;
+	size_t i, n, x[2], y[2], v, bits;
+	int d, colour;
+	ssize_t r;
+	size_t rows = 15u, cols = 32u;
+	unsigned char *art;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc > 1) {
+		if ('1' > argv[0][0u] || argv[0][0u] > '9' ||
+		    '1' > argv[1][0u] || argv[1][0u] > '9')
+			usage();
+
+		errno = 0;
+		rows = strtouz(argv[0], &end, 10);
+		if (!rows || *end || errno)
+			usage();
+		cols = strtouz(argv[1], &end, 10);
+		if (!cols || *end || errno)
+			usage();
+
+		argc -= 2;
+		argv += 2;
+	}
+
+	if (argc > 1)
+		usage();
+
+	if (argc) {
+		checksum = *argv;
+	} else {
+		for (;;) {
+			if (len == size)
+				data = erealloc(data, size += 128u);
+			r = read(STDIN_FILENO, &data[len], size - len);
+			if (r <= 0) {
+				if (!r)
+					break;
+				if (errno == EINVAL)
+					continue;
+				eprintf("read <stdin>:");
+			}
+			n = len + (size_t)r;
+			for (i = len; i < n; i++) {
+				if (('0' <= data[i] && data[i] <= '9') ||
+				    ('A' <= data[i] && data[i] <= 'F') ||
+				    ('a' <= data[i] && data[i] <= 'f'))
+					data[len++] = data[i];
+			}
+		}
+		data = erealloc(data, len + 1u);
+		data[len] = '\0';
+		checksum = data;
+	}
+
+	art = ecalloc(rows, cols);
+
+	x[0] = x[1] = cols / 2u;
+	y[0] = y[1] = rows / 2u;
+
+	colour = 0;
+	v = 0u;
+	bits = 0u;
+	for (i = 0u; checksum[i]; i++) {
+		if (('0' > checksum[i] || checksum[i] > '9') &&
+		    ('A' > checksum[i] || checksum[i] > 'F') &&
+		    ('a' > checksum[i] || checksum[i] > 'f'))
+			continue;
+		d = ((int)checksum[i] & 15) + (checksum[i] > '9' ? 9 : 0);
+		v <<= 4;
+		v |= (size_t)d;
+		bits += 4u;
+		while (bits >= BITS) {
+			x[colour] += (size_t)x_movements[v % ELEMSOF(x_movements)];
+			y[colour] += (size_t)y_movements[v % ELEMSOF(y_movements)];
+			x[colour] %= cols;
+			y[colour] %= rows;
+			cell = y[colour] * cols + x[colour];
+			art[cell] = (unsigned char)(art[cell] + (colour ? 0x20u : 1u));
+			art[cell] &= 0xEFu;
+			v >>= BITS;
+			bits -= BITS;
+			if (ELEMSOF(colours) > 1u)
+				colour ^= 1;
+		}
+	}
+	if (bits) {
+		x[colour] += (size_t)x_movements[v % ELEMSOF(x_movements)];
+		y[colour] += (size_t)y_movements[v % ELEMSOF(y_movements)];
+		x[colour] %= cols;
+		y[colour] %= rows;
+		cell = y[colour] * cols + x[colour];
+		art[cell] = (unsigned char)(art[cell] + (colour ? 0x20u : 1u));
+		art[cell] &= 0xEFu;
+	}
+
+	printf("+");
+	for (i = 0u; i < cols; i++)
+		printf("-");
+	printf("+\n");
+	for (*y = 0u; *y < rows; ++*y) {
+		printf("|");
+		for (*x = 0u; *x < cols; ++*x) {
+			cell = *y * cols + *x;
+			if (!art[cell]) {
+				printf(" ");
+				continue;
+			}
+			printf("\033[%sm%s\033[m",
+			       colours[(art[cell] / 0x20u) % ELEMSOF(colours)],
+			       symbols[(art[cell] & 0x0Fu) % ELEMSOF(symbols)]);
+		}
+		printf("|\n");
+	}
+	printf("+");
+	for (i = 0u; i < cols; i++)
+		printf("-");
+	printf("+\n");
+
+	if (ferror(stdout) || fclose(stdout))
+		eprintf("printf:");
+	free(art);
+	free(data);
+	return 0;
+}