--- a/simtool/saverestore.c	Mon Jan 25 00:14:19 2021 +0000
+++ b/simtool/saverestore.c	Mon Jan 25 01:23:54 2021 +0000
@@ -4,8 +4,11 @@
  */
 
 #include <sys/types.h>
+#include <sys/file.h>
+#include <sys/stat.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <pcsclite.h>
 #include <winscard.h>
 #include "globals.h"
@@ -87,3 +90,109 @@
 	fclose(of);
 	return(rc);
 }
+
+static
+restore_transparent(data)
+	u_char *data;
+{
+	unsigned off, cc;
+	int rc;
+
+	for (off = 0; off < curfile_total_size; off += cc) {
+		cc = curfile_total_size - off;
+		if (cc > 255)
+			cc = 255;
+		rc = update_bin_op(off, data + off, cc);
+		if (rc < 0)
+			return(rc);
+	}
+	return(0);
+}
+
+static
+restore_records(data)
+	u_char *data;
+{
+	unsigned recno;
+	u_char *dp;
+	int rc;
+
+	dp = data;
+	for (recno = 1; recno <= curfile_record_count; recno++) {
+		rc = update_rec_op(recno, 0x04, dp, curfile_record_len);
+		if (rc < 0)
+			return(rc);
+		dp += curfile_record_len;
+	}
+	return(0);
+}
+
+cmd_restore_file(argc, argv)
+	char **argv;
+{
+	int file_id, rc, fd;
+	struct stat st;
+	u_char *databuf;
+
+	if (isxdigit(argv[1][0]) && isxdigit(argv[1][1]) &&
+	    isxdigit(argv[1][2]) && isxdigit(argv[1][3]) && !argv[1][4])
+		file_id = strtoul(argv[1], 0, 16);
+	else
+		file_id = find_symbolic_file_name(argv[1]);
+	if (file_id < 0) {
+		fprintf(stderr,
+"error: file ID argument is not a hex value or a recognized symbolic name\n");
+		return(-1);
+	}
+	rc = select_op(file_id);
+	if (rc < 0)
+		return(rc);
+	rc = parse_ef_select_response();
+	if (rc < 0)
+		return(rc);
+	if (!curfile_total_size) {
+		printf("SIM indicates file of zero length, nothing to do\n");
+		return(0);
+	}
+	fd = open(argv[2], O_RDONLY);
+	if (fd < 0) {
+		perror(argv[2]);
+		return(-1);
+	}
+	fstat(fd, &st);
+	if ((st.st_mode & S_IFMT) != S_IFREG) {
+		fprintf(stderr, "error: %s is not a regular file\n", argv[2]);
+		close(fd);
+		return(-1);
+	}
+	if (st.st_size != curfile_total_size) {
+		fprintf(stderr,
+	"error: length of %s does not match SIM EF length of %u bytes\n",
+			argv[2], curfile_total_size);
+		close(fd);
+		return(-1);
+	}
+	databuf = malloc(curfile_total_size);
+	if (!databuf) {
+		perror("malloc for file data");
+		close(fd);
+		return(-1);
+	}
+	read(fd, databuf, curfile_total_size);
+	close(fd);
+	switch (curfile_structure) {
+	case 0x00:
+		/* transparent */
+		rc = restore_transparent(databuf);
+		break;
+	case 0x01:
+		/* record-based */
+		rc = restore_records(databuf);
+		break;
+	case 0x03:
+		fprintf(stderr, "error: cyclic files are not supported\n");
+		rc = -1;
+	}
+	free(databuf);
+	return(rc);
+}