in libs/curl/lib/mprintf.c [652:1036]
static int formatf(
void *userp, /* untouched by format(), just sent to the stream() function in
the second argument */
/* function pointer called for each output character */
int (*stream)(unsigned char, void *),
const char *format, /* %-formatted string */
va_list ap_save) /* list of parameters */
{
static const char nilstr[] = "(nil)";
const char *digits = lower_digits; /* Base-36 digits for numbers. */
int done = 0; /* number of characters written */
int i;
int ocount = 0; /* number of output segments */
int icount = 0; /* number of input arguments */
struct outsegment output[MAX_SEGMENTS];
struct va_input input[MAX_PARAMETERS];
char work[BUFFSIZE];
/* 'workend' points to the final buffer byte position, but with an extra
byte as margin to avoid the (false?) warning Coverity gives us
otherwise */
char *workend = &work[sizeof(work) - 2];
/* Parse the format string */
if(parsefmt(format, output, input, &ocount, &icount, ap_save))
return 0;
for(i = 0; i < ocount; i++) {
struct outsegment *optr = &output[i];
struct va_input *iptr;
bool is_alt; /* Format spec modifiers. */
int width; /* Width of a field. */
int prec; /* Precision of a field. */
bool is_neg; /* Decimal integer is negative. */
unsigned long base; /* Base of a number to be written. */
mp_uintmax_t num; /* Integral values to be written. */
mp_intmax_t signed_num; /* Used to convert negative in positive. */
char *w;
size_t outlen = optr->outlen;
unsigned int flags = optr->flags;
if(outlen) {
char *str = optr->start;
for(; outlen && *str; outlen--)
OUTCHAR(*str++);
if(optr->flags & FLAGS_SUBSTR)
/* this is just a substring */
continue;
}
/* pick up the specified width */
if(flags & FLAGS_WIDTHPARAM) {
width = (int)input[optr->width].val.nums;
if(width < 0) {
/* "A negative field width is taken as a '-' flag followed by a
positive field width." */
if(width == INT_MIN)
width = INT_MAX;
else
width = -width;
flags |= FLAGS_LEFT;
flags &= ~(unsigned int)FLAGS_PAD_NIL;
}
}
else
width = optr->width;
/* pick up the specified precision */
if(flags & FLAGS_PRECPARAM) {
prec = (int)input[optr->precision].val.nums;
if(prec < 0)
/* "A negative precision is taken as if the precision were
omitted." */
prec = -1;
}
else if(flags & FLAGS_PREC)
prec = optr->precision;
else
prec = -1;
is_alt = (flags & FLAGS_ALT) ? 1 : 0;
iptr = &input[optr->input];
switch(iptr->type) {
case FORMAT_INTU:
case FORMAT_LONGU:
case FORMAT_LONGLONGU:
flags |= FLAGS_UNSIGNED;
FALLTHROUGH();
case FORMAT_INT:
case FORMAT_LONG:
case FORMAT_LONGLONG:
num = iptr->val.numu;
if(flags & FLAGS_CHAR) {
/* Character. */
if(!(flags & FLAGS_LEFT))
while(--width > 0)
OUTCHAR(' ');
OUTCHAR((char) num);
if(flags & FLAGS_LEFT)
while(--width > 0)
OUTCHAR(' ');
break;
}
if(flags & FLAGS_OCTAL) {
/* Octal unsigned integer */
base = 8;
is_neg = FALSE;
}
else if(flags & FLAGS_HEX) {
/* Hexadecimal unsigned integer */
digits = (flags & FLAGS_UPPER)? upper_digits : lower_digits;
base = 16;
is_neg = FALSE;
}
else if(flags & FLAGS_UNSIGNED) {
/* Decimal unsigned integer */
base = 10;
is_neg = FALSE;
}
else {
/* Decimal integer. */
base = 10;
is_neg = (iptr->val.nums < (mp_intmax_t)0);
if(is_neg) {
/* signed_num might fail to hold absolute negative minimum by 1 */
signed_num = iptr->val.nums + (mp_intmax_t)1;
signed_num = -signed_num;
num = (mp_uintmax_t)signed_num;
num += (mp_uintmax_t)1;
}
}
number:
/* Supply a default precision if none was given. */
if(prec == -1)
prec = 1;
/* Put the number in WORK. */
w = workend;
switch(base) {
case 10:
while(num > 0) {
*w-- = (char)('0' + (num % 10));
num /= 10;
}
break;
default:
while(num > 0) {
*w-- = digits[num % base];
num /= base;
}
break;
}
width -= (int)(workend - w);
prec -= (int)(workend - w);
if(is_alt && base == 8 && prec <= 0) {
*w-- = '0';
--width;
}
if(prec > 0) {
width -= prec;
while(prec-- > 0 && w >= work)
*w-- = '0';
}
if(is_alt && base == 16)
width -= 2;
if(is_neg || (flags & FLAGS_SHOWSIGN) || (flags & FLAGS_SPACE))
--width;
if(!(flags & FLAGS_LEFT) && !(flags & FLAGS_PAD_NIL))
while(width-- > 0)
OUTCHAR(' ');
if(is_neg)
OUTCHAR('-');
else if(flags & FLAGS_SHOWSIGN)
OUTCHAR('+');
else if(flags & FLAGS_SPACE)
OUTCHAR(' ');
if(is_alt && base == 16) {
OUTCHAR('0');
if(flags & FLAGS_UPPER)
OUTCHAR('X');
else
OUTCHAR('x');
}
if(!(flags & FLAGS_LEFT) && (flags & FLAGS_PAD_NIL))
while(width-- > 0)
OUTCHAR('0');
/* Write the number. */
while(++w <= workend) {
OUTCHAR(*w);
}
if(flags & FLAGS_LEFT)
while(width-- > 0)
OUTCHAR(' ');
break;
case FORMAT_STRING: {
const char *str;
size_t len;
str = (char *)iptr->val.str;
if(!str) {
/* Write null string if there is space. */
if(prec == -1 || prec >= (int) sizeof(nilstr) - 1) {
str = nilstr;
len = sizeof(nilstr) - 1;
/* Disable quotes around (nil) */
flags &= ~(unsigned int)FLAGS_ALT;
}
else {
str = "";
len = 0;
}
}
else if(prec != -1)
len = (size_t)prec;
else if(*str == '\0')
len = 0;
else
len = strlen(str);
width -= (len > INT_MAX) ? INT_MAX : (int)len;
if(flags & FLAGS_ALT)
OUTCHAR('"');
if(!(flags & FLAGS_LEFT))
while(width-- > 0)
OUTCHAR(' ');
for(; len && *str; len--)
OUTCHAR(*str++);
if(flags & FLAGS_LEFT)
while(width-- > 0)
OUTCHAR(' ');
if(flags & FLAGS_ALT)
OUTCHAR('"');
break;
}
case FORMAT_PTR:
/* Generic pointer. */
if(iptr->val.ptr) {
/* If the pointer is not NULL, write it as a %#x spec. */
base = 16;
digits = (flags & FLAGS_UPPER)? upper_digits : lower_digits;
is_alt = TRUE;
num = (size_t) iptr->val.ptr;
is_neg = FALSE;
goto number;
}
else {
/* Write "(nil)" for a nil pointer. */
const char *point;
width -= (int)(sizeof(nilstr) - 1);
if(flags & FLAGS_LEFT)
while(width-- > 0)
OUTCHAR(' ');
for(point = nilstr; *point != '\0'; ++point)
OUTCHAR(*point);
if(!(flags & FLAGS_LEFT))
while(width-- > 0)
OUTCHAR(' ');
}
break;
case FORMAT_DOUBLE: {
char formatbuf[32]="%";
char *fptr = &formatbuf[1];
size_t left = sizeof(formatbuf)-strlen(formatbuf);
int len;
if(flags & FLAGS_WIDTH)
width = optr->width;
if(flags & FLAGS_PREC)
prec = optr->precision;
if(flags & FLAGS_LEFT)
*fptr++ = '-';
if(flags & FLAGS_SHOWSIGN)
*fptr++ = '+';
if(flags & FLAGS_SPACE)
*fptr++ = ' ';
if(flags & FLAGS_ALT)
*fptr++ = '#';
*fptr = 0;
if(width >= 0) {
size_t dlen;
if(width >= (int)sizeof(work))
width = sizeof(work)-1;
/* RECURSIVE USAGE */
dlen = (size_t)curl_msnprintf(fptr, left, "%d", width);
fptr += dlen;
left -= dlen;
}
if(prec >= 0) {
/* for each digit in the integer part, we can have one less
precision */
size_t maxprec = sizeof(work) - 2;
double val = iptr->val.dnum;
if(width > 0 && prec <= width)
maxprec -= (size_t)width;
while(val >= 10.0) {
val /= 10;
maxprec--;
}
if(prec > (int)maxprec)
prec = (int)maxprec-1;
if(prec < 0)
prec = 0;
/* RECURSIVE USAGE */
len = curl_msnprintf(fptr, left, ".%d", prec);
fptr += len;
}
if(flags & FLAGS_LONG)
*fptr++ = 'l';
if(flags & FLAGS_FLOATE)
*fptr++ = (char)((flags & FLAGS_UPPER) ? 'E':'e');
else if(flags & FLAGS_FLOATG)
*fptr++ = (char)((flags & FLAGS_UPPER) ? 'G' : 'g');
else
*fptr++ = 'f';
*fptr = 0; /* and a final null-termination */
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wformat-nonliteral"
#endif
/* NOTE NOTE NOTE!! Not all sprintf implementations return number of
output characters */
#ifdef HAVE_SNPRINTF
(snprintf)(work, sizeof(work), formatbuf, iptr->val.dnum);
#else
(sprintf)(work, formatbuf, iptr->val.dnum);
#endif
#ifdef __clang__
#pragma clang diagnostic pop
#endif
DEBUGASSERT(strlen(work) <= sizeof(work));
for(fptr = work; *fptr; fptr++)
OUTCHAR(*fptr);
break;
}
case FORMAT_INTPTR:
/* Answer the count of characters written. */
#ifdef HAVE_LONG_LONG_TYPE
if(flags & FLAGS_LONGLONG)
*(LONG_LONG_TYPE *) iptr->val.ptr = (LONG_LONG_TYPE)done;
else
#endif
if(flags & FLAGS_LONG)
*(long *) iptr->val.ptr = (long)done;
else if(!(flags & FLAGS_SHORT))
*(int *) iptr->val.ptr = (int)done;
else
*(short *) iptr->val.ptr = (short)done;
break;
default:
break;
}
}
return done;
}