initial checkout from wrc

1 files changed, 49 insertions, 0 deletions

diff --git a/lib/cvthex.c b/lib/cvthex.c
new file mode 100644
index 0000000..5f3da19
--- /dev/null
+++ b/lib/cvthex.c
@@ -0,0 +1,49 @@
+/**
+** @file	cvthex.c
+**
+** @author	Numerous CSCI-452 classes
+**
+** @brief	C implementations of common library functions
+*/
+
+#ifndef CVTHEX_SRC_INC
+#define CVTHEX_SRC_INC
+
+#include <common.h>
+
+#include <lib.h>
+
+/**
+** cvthex(buf,value)
+**
+** convert a 32-bit unsigned value into a minimal-length (up to
+** 8-character) NUL-terminated character string
+**
+** @param buf    Destination buffer
+** @param value  Value to convert
+**
+** @return The number of characters placed into the buffer
+**          (not including the NUL)
+**
+** NOTE:  assumes buf is large enough to hold the resulting string
+*/
+int cvthex( char *buf, uint32_t value ) {
+	const char hexdigits[] = "0123456789ABCDEF";
+	int chars_stored = 0;
+
+	for( int i = 0; i < 8; i += 1 ) {
+		uint32_t val = value & 0xf0000000;
+		if( chars_stored || val != 0 || i == 7 ) {
+			++chars_stored;
+			val = (val >> 28) & 0xf;
+			*buf++ = hexdigits[val];
+		}
+		value <<= 4;
+	}
+
+	*buf = '\0';
+
+	return( chars_stored );
+}
+
+#endif