X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/060df5ea7c632b1ac8cc8aac1fb59758165c2084..6d2010ae8f7a6078e10b361c6962983bab233e0f:/libsyscall/mach/string.c

diff --git a/libsyscall/mach/string.c b/libsyscall/mach/string.c
new file mode 100644
index 000000000..000a0f88f
--- /dev/null
+++ b/libsyscall/mach/string.c
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2010 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+#include "string.h"
+
+static const char hex[] = "0123456789abcdef";
+
+static int
+_mach_strlen(const char *str)
+{
+	const char *p;
+	for (p = str; p; p++) {
+		if (*p == '\0') {
+			return (p - str);
+		}
+	}
+	/* NOTREACHED */
+	return 0;
+}
+
+static void
+_mach_hex(char **buffer, int *length, unsigned long long n)
+{
+	char buf[32];
+	char *cp = buf + sizeof(buf);
+	
+	if (n) {
+		*--cp = '\0';
+		while (n) {
+			*--cp = hex[n & 0xf];
+			n >>= 4;
+		}
+		
+		int width = _mach_strlen(cp);
+		while (width > 0 && length > 0) {
+			*(*buffer)++ = *cp++;
+			(*length)--;
+			width--;
+		}
+	}
+}
+
+int
+_mach_vsnprintf(char *buffer, int length, const char *fmt, va_list ap)
+{
+	int width, max = length;
+	char *out_ptr = buffer;
+	
+	// we only ever write n-1 bytes so we can put a \0 at the end
+	length--;
+	while (length > 0 && *fmt) {
+		if (*fmt == '\0') {
+			break;
+		}
+		if (*fmt != '%') {
+			*(out_ptr++) = *(fmt++);
+			length--;
+			continue;
+		}
+		fmt++;
+		// only going to support a specific subset of sprintf flags
+		// namely %s, %x, with no padding modifiers
+		switch (*fmt++) {
+			case 's':
+			{
+				char *cp = va_arg(ap, char*);
+				width = _mach_strlen(cp);
+				while (width > 0 && length > 0) {
+					*(out_ptr++) = *(cp++);
+					width--;
+					length--;
+				}
+				break;
+			}
+			case 'x':
+			{
+				_mach_hex(&out_ptr, &length, va_arg(ap, unsigned int));
+				break;
+			}
+		}
+	}
+	*out_ptr = '\0';
+	return max - length;
+}
+
+int
+_mach_snprintf(char *buffer, int length, const char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+	va_start(ap, fmt);
+	ret = _mach_vsnprintf(buffer, length, fmt, ap);
+	va_end(ap);
+	return ret;
+}