--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netdiff/flip2pin/readlist.c	Sun Nov 15 03:32:48 2020 +0000
@@ -0,0 +1,71 @@
+#include <ctype.h>
+#include <string.h>
+#include <strings.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "struct.h"
+
+extern struct flip_list *flip_list;
+
+static char *infname;
+static FILE *inf;
+static char linebuf[256];
+static int lineno;
+
+static void
+refdes_entry(entry)
+	char *entry;
+{
+	struct flip_list *rp, **rpp;
+	char *dp;
+
+	for (rpp = &flip_list; rp = *rpp; rpp = &rp->next) {
+		if (!strcmp(rp->refdes, entry)) {
+			fprintf(stderr, "%s line %d: refdes %s given twice\n",
+				infname, lineno, entry);
+			exit(1);
+		}
+	}
+	rp = malloc(sizeof(struct flip_list) + strlen(entry) + 1);
+	dp = (char *)(rp + 1);
+	rp->refdes = dp;
+	strcpy(dp, entry);
+	rp->next = 0;
+	*rpp = rp;
+}
+
+static void
+process_line()
+{
+	char *cp, *np;
+
+	for (cp = linebuf; ; ) {
+		while (isspace(*cp))
+			cp++;
+		if (*cp == '\0' || *cp == '#')
+			break;
+		np = cp;
+		while (*cp && !isspace(*cp))
+			cp++;
+		if (*cp)
+			*cp++ = '\0';
+		refdes_entry(np);
+	}
+}
+
+read_flip_list(input_filename)
+	char *input_filename;
+{
+	infname = input_filename;
+	inf = fopen(infname, "r");
+	if (!inf) {
+		perror(infname);
+		exit(1);
+	}
+	while (fgets(linebuf, sizeof linebuf, inf)) {
+		lineno++;
+		process_line();
+	}
+	fclose(inf);
+	return(0);
+}