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-rw-r--r--lib/cvthex.c49
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diff --git a/lib/cvthex.c b/lib/cvthex.c
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+/**
+** @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