Escape/unescape commas when serializing/deserializing a stringlist.

plugins/sudoers/unesc_str.c

@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2022 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <string.h>
+
+/*
+ * Remove backslash escape chars.
+ */
+void
+unescape_string(char *str)
+{
+    char *cp = str;
+    char *ep = str + strlen(str);
+
+    while ((cp = strchr(cp, '\\')) != NULL) {
+	if (cp[1] == '\0')
+	    break;
+	memmove(cp, cp + 1, (size_t)(ep - cp));
+	cp++;
+	ep--;
+    }
+}