--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netdiff/flip2pin/mainproc.c	Sun Nov 15 03:32:48 2020 +0000
@@ -0,0 +1,115 @@
+#include <ctype.h>
+#include <string.h>
+#include <strings.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "struct.h"
+
+extern struct flip_list *flip_list;
+
+#define	MAX_FIELDS	2
+
+static char *infname;
+static FILE *inf;
+static char linebuf[512];
+static int lineno;
+static char *fields[MAX_FIELDS];
+static unsigned nfields;
+
+static
+get_line()
+{
+	if (!fgets(linebuf, sizeof linebuf, inf))
+		return(0);
+	lineno++;
+	if (!index(linebuf, '\n')) {
+		fprintf(stderr, "%s line %d: missing newline\n",
+			infname, lineno);
+		exit(1);
+	}
+	return(1);
+}
+
+static void
+parse_into_fields()
+{
+	char *cp;
+
+	nfields = 0;
+	for (cp = linebuf; ; ) {
+		while (isspace(*cp))
+			cp++;
+		if (*cp == '\0' || *cp == '#')
+			break;
+		if (nfields >= MAX_FIELDS) {
+			fprintf(stderr, "%s line %d: too many fields\n",
+				infname, lineno);
+			exit(1);
+		}
+		fields[nfields++] = cp;
+		while (*cp && !isspace(*cp))
+			cp++;
+		if (*cp)
+			*cp++ = '\0';
+	}
+}
+
+static void
+process_netpoint()
+{
+	char *cp, *refdes, *pin;
+	struct flip_list *rp;
+
+	cp = index(fields[1], '.');
+	if (!cp) {
+		fprintf(stderr, "%s line %d: expected '.' not found\n",
+			infname, lineno);
+		exit(1);
+	}
+	*cp++ = '\0';
+	refdes = fields[1];
+	pin = cp;
+	for (rp = flip_list; rp; rp = rp->next) {
+		if (!strcmp(refdes, rp->refdes))
+			break;
+	}
+	if (rp) {
+		if (!strcmp(pin, "1"))
+			pin = "2";
+		else if (!strcmp(pin, "2"))
+			pin = "1";
+		else {
+			fprintf(stderr,
+				"%s line %d: flip pin number is not 1 or 2\n",
+				infname, lineno);
+			exit(1);
+		}
+	}
+	printf("%s\t%s.%s\n", fields[0], refdes, pin);
+}
+
+main_process(input_filename)
+	char *input_filename;
+{
+	infname = input_filename;
+	inf = fopen(infname, "r");
+	if (!inf) {
+		perror(infname);
+		exit(1);
+	}
+	for (;;) {
+		if (!get_line())
+			break;
+		parse_into_fields();
+		if (!nfields)
+			continue;
+		if (nfields != 2) {
+			fprintf(stderr, "%s line %d: expected 2 fields\n",
+				infname, lineno);
+			exit(1);
+		}
+		process_netpoint();
+	}
+	fclose(inf);
+	return(0);
+}