First commit containing CP/M 3 help files

src/makehelp.c

@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <ctype.h>
+
+struct helptoc {
+	char topic[12];
+	uint16_t recoff;
+	uint8_t bytoff;
+	uint8_t level;
+} __attribute__((packed));
+
+// input file must have already been converted LF => CR,LF.
+// Typically, a concatination of all help files.
+int main(int argc, char **argv) {
+	struct stat stb;
+	char *buf = NULL;
+	size_t buflen = 0;
+	struct helptoc toc;
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s <help-file>\n", argv[0]);
+		exit(1);
+	}
+	int x;
+	int fd = open(argv[1], O_RDONLY);
+	if (fd < 0) {
+		perror(argv[1]);
+		exit(1);
+	}
+	fstat(fd, &stb);
+	buflen = stb.st_size;
+	buflen = (buflen + 127) & ~127;
+	buf = malloc(buflen + 1);
+	if (buf == NULL) {
+		perror("malloc");
+		exit(1);
+	}
+	int rc = read(fd, buf, stb.st_size);
+	if (rc < 0) {
+		perror(argv[1]);
+		exit(1);
+	}
+	close(fd);
+	memset(buf + stb.st_size, 0, (buflen + 1) - stb.st_size);
+
+	// Line endings MUST be CR-LF... always...
+	// CR-LF are considered the START of the text...
+	char *s = buf;
+	x = 0;
+	while ((s = strstr(s, "///")) != NULL) {
+		++x;
+		while (*s && *s != '\r') ++s;
+	}
+	// compute size of TOC... base of all offsets...
+	int ntoc = ((x + 7) & ~7);
+	if (ntoc == x) {
+		ntoc += 8;
+	}
+	int toclen = ntoc * sizeof(struct helptoc);
+	// Now go through text again, building TOC (on stdout)...
+	int t = 0;
+	s = buf;
+	while ((s = strstr(s, "///")) != NULL) {
+		s += 3;
+		toc.level = *s++ - '0';
+		x = 0;
+		while (x < sizeof(toc.topic) && *s && *s != '\r') {
+			toc.topic[x++] = toupper(*s++);
+		}
+		while (x < sizeof(toc.topic)) {
+			toc.topic[x++] = ' ';
+		}
+		while (*s && *s != '\r') ++s;
+		int off = ((s - buf) + toclen);
+		toc.recoff = off >> 7;
+		toc.bytoff = off & 0x7f;
+		write(1, &toc, sizeof(toc));
+		++t;
+	}
+	memset(toc.topic, ' ', sizeof(toc.topic));
+	toc.topic[0] = '$';
+	toc.level = 0;
+	toc.recoff = 0;
+	toc.bytoff = 0;
+	while (t < ntoc) {
+		write(1, &toc, sizeof(toc));
+		++t;
+	}
+	// now dump the help text...
+	write(1, buf, buflen);
+	return 0;
+}