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Diffstat (limited to 'lib/cvthex.c')
-rw-r--r-- | lib/cvthex.c | 49 |
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 |