--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/f-demime/b2q_out.c	Sat May 06 06:14:03 2023 +0000
@@ -0,0 +1,90 @@
+/*
+ * This module implements the output side of base64-to-QP conversion.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include "defs.h"
+
+extern FILE *tempfile;
+
+static char linebuf[QP_MAX_LINE];
+static unsigned line_len, trailing_newline;
+
+static void
+add_plain_char(ch)
+{
+	linebuf[line_len++] = ch;
+	linebuf[line_len] = '\0';
+	if (!strcmp(linebuf, "From ")) {
+		strcpy(linebuf, "=46rom ");
+		line_len = 7;
+	} else if (!strcmp(linebuf, "--")) {
+		strcpy(linebuf, "=2D-");
+		line_len = 4;
+	} else if (!strcmp(linebuf, ".")) {
+		strcpy(linebuf, "=2E");
+		line_len = 3;
+	}
+}
+
+static void
+add_octet_char(ch)
+{
+	sprintf(linebuf + line_len, "=%02X", ch);
+	line_len += 3;
+}
+
+static void
+process_newline()
+{
+	if (line_len) {
+		if (linebuf[line_len-1] == ' ')
+			strcpy(linebuf + line_len - 1, "=20");
+		fputs(linebuf, stdout);
+		line_len = 0;
+	}
+	putchar('\n');
+}
+
+static void
+process_char(ch)
+{
+	if (ch == '\n') {
+		process_newline();
+		trailing_newline++;
+		if (trailing_newline > 2)
+			trailing_newline = 2;
+		return;
+	}
+	if (line_len >= QP_MAX_LINE - 2) {
+		printf("%s=\n", linebuf);
+		line_len = 0;
+	}
+	if (ch == '=')
+		add_octet_char(ch);
+	else if (ch >= ' ' && ch <= '~')
+		add_plain_char(ch);
+	else
+		add_octet_char(ch);
+	trailing_newline = 0;
+}
+
+void
+b2q_emit_output()
+{
+	int c;
+
+	rewind(tempfile);
+	line_len = 0;
+	trailing_newline = 1;
+	while ((c = getc(tempfile)) != EOF)
+		process_char(c);
+	fclose(tempfile);
+	while (trailing_newline < 2) {
+		process_newline();
+		trailing_newline++;
+	}
+}