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#include "scan.h"
/* this is cut and paste from scan_ulong instead of calling scan_ulong
* because this way scan_ushort can abort scanning when the number would
* not fit into an unsigned short (as opposed to not fitting in an
* unsigned long) */
size_t scan_ushort(const char* src,unsigned short* dest) {
if (sizeof(unsigned short) == sizeof(unsigned int)) {
/* a good optimizing compiler should remove the else clause when not
* needed */
return scan_uint(src,(unsigned int*)dest);
} if (sizeof(unsigned short) < sizeof(unsigned long)) {
/* this is the regular case */
const char* cur;
unsigned short l;
for (cur=src,l=0; *cur>='0' && *cur<='9'; ++cur) {
unsigned long tmp=l*10ul+*cur-'0';
if ((unsigned short)tmp != tmp) break;
l=tmp;
}
if (cur>src) *dest=l;
return (size_t)(cur-src);
} else {
/* the C standard says that sizeof(short) <= sizeof(unsigned int) <=
* sizeof(unsigned long); this can never happen. Provoke a compile
* error if it does */
char compileerror[sizeof(unsigned long)-sizeof(unsigned short)];
(void)compileerror;
}
}
#ifdef UNITTEST
#include <assert.h>
int main() {
unsigned short i;
assert(scan_ushort("1234",&i)==4 && i==1234);
assert(scan_ushort("-1",&i)==0);
if (sizeof(short)==2) {
assert(scan_ushort("123456",&i)==5 && i==12345);
}
return 0;
}
#endif
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