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Merged in david_s5/nuttx/upstream_to_greg_scanfwidth (pull request #149)

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Fixes sscan %sn where strlen(data) < n
This commit is contained in:
Gregory Nutt 2016-10-15 16:10:08 +00:00
commit db8863622b
1 changed files with 94 additions and 114 deletions
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208
libc/stdio/lib_sscanf.c
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@ -93,8 +93,7 @@ static int findwidth(FAR const char *buf, FAR const char *fmt)
FAR const char *next = fmt + 1;
/* No... is there a space after the format? Or does the format string end
* here?
*/
* here? */
if (isspace(*next) || *next == 0)
{
@ -103,15 +102,13 @@ static int findwidth(FAR const char *buf, FAR const char *fmt)
return strcspn(buf, spaces);
}
/* No.. Another possibility is the format character is followed by
* some recognizable delimiting value.
*/
/* No.. Another possibility is the format character is followed by some
* recognizable delimiting value. */
if (*next != '%')
{
/* If so we will say that the string ends there if we can find that
* delimiter in the input string.
*/
* delimiter in the input string. */
FAR const char *ptr = strchr(buf, *next);
if (ptr)
@ -120,16 +117,14 @@ static int findwidth(FAR const char *buf, FAR const char *fmt)
}
}
/* No... the format has no delimiter and is back-to-back with the next
* format (or is followed by a delimiter that does not exist in the
* input string). At this point we just bail and Use the input up until
* the first white space is encountered.
*
* NOTE: This means that values from the following format may be
* concatenated with the first. This is a bug. We have no generic way of
* determining the width of the data if there is no fieldwidth, no space
* separating the input, and no usable delimiter character.
*/
/* No... the format has no delimiter and is back-to-back with the next format
* (or is followed by a delimiter that does not exist in the input string).
* At this point we just bail and Use the input up until the first white
* space is encountered. NOTE: This means that values from the following
* format may be concatenated with the first. This is a bug. We have no
* generic way of determining the width of the data if there is no
* fieldwidth, no space separating the input, and no usable delimiter
* character. */
return strcspn(buf, spaces);
}
@ -149,7 +144,7 @@ static int findwidth(FAR const char *buf, FAR const char *fmt)
int sscanf(FAR const char *buf, FAR const char *fmt, ...)
{
va_list ap;
int count;
int count;
va_start(ap, fmt);
count = vsscanf((FAR const char *)buf, fmt, ap);
@ -168,34 +163,33 @@ int sscanf(FAR const char *buf, FAR const char *fmt, ...)
int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
{
FAR const char *bufstart;
FAR char *tv;
FAR char *tv;
FAR const char *tc;
bool lflag;
bool noassign;
int count;
int width;
int base = 10;
char tmp[MAXLN];
bool lflag;
bool noassign;
int count;
int width;
int fwidth;
int base = 10;
char tmp[MAXLN];
linfo("vsscanf: buf=\"%s\" fmt=\"%s\"\n", buf, fmt);
/* Remember the start of the input buffer. We will need this for %n
* calculations.
*/
* calculations. */
bufstart = buf;
/* Parse the format, extracting values from the input buffer as needed */
count = 0;
width = 0;
count = 0;
width = 0;
noassign = false;
lflag = false;
lflag = false;
/* Loop until all characters in the fmt string have been processed. We
* may have to continue loop after reaching the end the input data in
* order to handle trailing %n format specifiers.
*/
/* Loop until all characters in the fmt string have been processed. We may
* have to continue loop after reaching the end the input data in order to
* handle trailing %n format specifiers. */
while (*fmt)
{
@ -244,27 +238,25 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
}
/* Process %s: String conversion */
/* Process %s: String conversion */
if (*fmt == 's')
{
linfo("vsscanf: Performing string conversion\n");
/* Get a pointer to the char * value. We need to do this even
* if we have reached the end of the input data in order to
* update the 'ap' variable.
*/
/* Get a pointer to the char * value. We need to do this even if
* we have reached the end of the input data in order to update
* the 'ap' variable. */
tv = NULL; /* To avoid warnings about begin uninitialized */
tv = NULL; /* To avoid warnings about begin uninitialized */
if (!noassign)
{
tv = va_arg(ap, FAR char *);
tv = va_arg(ap, FAR char *);
tv[0] = '\0';
}
/* But we only perform the data conversion is we still have
* bytes remaining in the input data stream.
*/
/* But we only perform the data conversion is we still have bytes
* remaining in the input data stream. */
if (*buf)
{
@ -275,16 +267,21 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
buf++;
}
/* Was a fieldwidth specified? */
/* Guess a field width using some heuristics */
if (!width)
fwidth = findwidth(buf, fmt);
/* Use the actual field's width if 1) no fieldwidth specified
* or 2) the actual field's width is smaller than fieldwidth
* specified */
if (!width || fwidth < width)
{
/* No... Guess a field width using some heuristics */
int tmpwidth = findwidth(buf, fmt);
width = MIN(sizeof(tmp) - 1, tmpwidth);
width = fwidth;
}
width = MIN(sizeof(tmp) - 1, width);
/* Copy the string (if we are making an assignment) */
if (!noassign)
@ -300,27 +297,25 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
}
/* Process %c: Character conversion */
/* Process %c: Character conversion */
else if (*fmt == 'c')
{
linfo("vsscanf: Performing character conversion\n");
/* Get a pointer to the char * value. We need to do this even
* if we have reached the end of the input data in order to
* update the 'ap' variable.
*/
/* Get a pointer to the char * value. We need to do this even if
* we have reached the end of the input data in order to update
* the 'ap' variable. */
tv = NULL; /* To avoid warnings about beign uninitialized */
tv = NULL; /* To avoid warnings about beign uninitialized */
if (!noassign)
{
tv = va_arg(ap, FAR char *);
tv = va_arg(ap, FAR char *);
tv[0] = '\0';
}
/* But we only perform the data conversion is we still have
* bytes remaining in the input data stream.
*/
/* But we only perform the data conversion is we still have bytes
* remaining in the input data stream. */
if (*buf)
{
@ -343,33 +338,30 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
/* Update the buffer pointer past the character(s) in the
* input
*/
* input */
buf += width;
}
}
/* Process %d, %o, %b, %x, %u: Various integer conversions */
/* Process %d, %o, %b, %x, %u: Various integer conversions */
else if (strchr("dobxu", *fmt))
{
FAR long *plong = NULL;
FAR int *pint = NULL;
FAR int *pint = NULL;
bool sign;
linfo("vsscanf: Performing integer conversion\n");
/* Get a pointer to the integer value. We need to do this even
* if we have reached the end of the input data in order to
* update the 'ap' variable.
*/
* update the 'ap' variable. */
if (!noassign)
{
/* We have to check whether we need to return a long or an
* int.
*/
* int. */
if (lflag)
{
@ -383,15 +375,14 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
}
/* But we only perform the data conversion if we still have
* bytes remaining in the input data stream.
*/
/* But we only perform the data conversion if we still have bytes
* remaining in the input data stream. */
if (*buf)
{
FAR char *endptr;
int errsave;
long tmplong;
int errsave;
long tmplong;
/* Skip over any white space before the integer string */
@ -400,9 +391,8 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
buf++;
}
/* The base of the integer conversion depends on the
* specific conversion specification.
*/
/* The base of the integer conversion depends on the specific
* conversion specification. */
sign = false;
switch (*fmt)
@ -438,9 +428,7 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
width = MIN(sizeof(tmp) - 1, tmpwidth);
}
/* Copy the numeric string into a temporary working
* buffer.
*/
/* Copy the numeric string into a temporary working buffer. */
strncpy(tmp, buf, width);
tmp[width] = '\0';
@ -475,9 +463,8 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
if (!noassign)
{
/* We have to check whether we need to return a long
* or an int.
*/
/* We have to check whether we need to return a long or
* an int. */
if (lflag)
{
@ -487,8 +474,7 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
else
{
linfo("vsscanf: Return %ld to 0x%p\n",
tmplong, pint);
linfo("vsscanf: Return %ld to 0x%p\n", tmplong, pint);
*pint = (int)tmplong;
}
@ -497,48 +483,44 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
}
/* Process %a, %A, %f, %F, %e, %E, %g, and %G: Floating point
* conversions
*/
/* Process %a, %A, %f, %F, %e, %E, %g, and %G: Floating point
* conversions */
else if (strchr("aAfFeEgG", *fmt) != NULL)
{
#ifdef CONFIG_HAVE_DOUBLE
FAR double_t *pd = NULL;
#endif
FAR float *pf = NULL;
FAR float *pf = NULL;
linfo("vsscanf: Performing floating point conversion\n");
/* Get a pointer to the double value. We need to do this even
* if we have reached the end of the input data in order to
* update the 'ap' variable.
*/
/* Get a pointer to the double value. We need to do this even if
* we have reached the end of the input data in order to update
* the 'ap' variable. */
if (!noassign)
{
/* We have to check whether we need to return a float or a
* double.
*/
* double. */
#ifdef CONFIG_HAVE_DOUBLE
if (lflag)
{
pd = va_arg(ap, FAR double_t *);
pd = va_arg(ap, FAR double_t *);
*pd = 0.0;
}
else
#endif
{
pf = va_arg(ap, FAR float *);
pf = va_arg(ap, FAR float *);
*pf = 0.0;
}
}
#ifdef CONFIG_LIBC_FLOATINGPOINT
/* But we only perform the data conversion is we still have
* bytes remaining in the input data stream.
*/
/* But we only perform the data conversion is we still have bytes
* remaining in the input data stream. */
if (*buf)
{
@ -573,14 +555,14 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
/* strtod always returns a double */
FAR char *endptr;
int errsave;
double_t dvalue;
int errsave;
double_t dvalue;
/* Preserve the errno value */
errsave = get_errno();
set_errno(0);
dvalue = strtod(tmp, &endptr);
dvalue = strtod(tmp, &endptr);
/* Check if the number was successfully converted */
@ -591,18 +573,17 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
set_errno(errsave);
/* We have to check whether we need to return a float
* or a double.
*/
/* We have to check whether we need to return a float or
* a double. */
#ifdef CONFIG_HAVE_DOUBLE
# ifdef CONFIG_HAVE_DOUBLE
if (lflag)
{
linfo("vsscanf: Return %f to %p\n", dvalue, pd);
*pd = dvalue;
}
else
#endif
# endif
{
linfo("vsscanf: Return %f to %p\n", dvalue, pf);
*pf = (float)dvalue;
@ -614,7 +595,7 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
#endif
}
/* Process %n: Character count */
/* Process %n: Character count */
else if (*fmt == 'n')
{
@ -622,7 +603,7 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
if (!noassign)
{
size_t nchars = (size_t)(buf - bufstart);
size_t nchars = (size_t) (buf - bufstart);
/* Note %n does not count as a conversion */
@ -639,14 +620,14 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
}
width = 0;
width = 0;
noassign = false;
lflag = false;
lflag = false;
fmt++;
}
/* It is not a conversion specifier */
/* It is not a conversion specifier */
else if (*buf)
{
@ -678,8 +659,7 @@ int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
}
/* sscanf is required to return EOF if the input ends before the first
* matching failure or conversion.
*/
* matching failure or conversion. */
return count ? count : EOF;
}