static char
eat_escape_code(void)
{
int c, coded_char;
c = input();
switch (c) {
case 0: /* i.e., EOF */
unput(c);
return(c);
case '\n':
return(0);
case 'n':
return('\n');
case 't':
return('\t');
case 'b':
return('\b');
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
coded_char = c - '0';
c = input();
if (!is_octal_digit(c)) {
unput(c);
return(coded_char);
}
coded_char = coded_char*8 + c-'0';
c = input();
if (!is_octal_digit(c)) {
unput(c);
return(coded_char);
}
return(coded_char*8 + c-'0');
default:
return(c);
}
}
/* Print a \ escape sequence starting at ESCSTART.
Return the number of characters in the escape sequence
besides the backslash.
If OCTAL_0 is nonzero, octal escapes are of the form \0ooo, where o
is an octal digit; otherwise they are of the form \ooo. */
long builtin_printf_state_t::print_esc(const wchar_t *escstart, bool octal_0)
{
const wchar_t *p = escstart + 1;
int esc_value = 0; /* Value of \nnn escape. */
int esc_length; /* Length of \nnn escape. */
if (*p == L'x')
{
/* A hexadecimal \xhh escape sequence must have 1 or 2 hex. digits. */
for (esc_length = 0, ++p; esc_length < 2 && is_hex_digit(*p); ++esc_length, ++p)
esc_value = esc_value * 16 + hex_to_bin(*p);
if (esc_length == 0)
this->fatal_error(_(L"missing hexadecimal number in escape"));
this->append_format_output(L"%lc", esc_value);
}
else if (is_octal_digit(*p))
{
/* Parse \0ooo (if octal_0 && *p == L'0') or \ooo (otherwise).
Allow \ooo if octal_0 && *p != L'0'; this is an undocumented
extension to POSIX that is compatible with Bash 2.05b. */
for (esc_length = 0, p += octal_0 && *p == L'0'; esc_length < 3 && is_octal_digit(*p); ++esc_length, ++p)
esc_value = esc_value * 8 + octal_to_bin(*p);
this->append_format_output(L"%c", esc_value);
}
else if (*p && wcschr(L"\"\\abcfnrtv", *p))
print_esc_char(*p++);
else if (*p == L'u' || *p == L'U')
{
wchar_t esc_char = *p;
p++;
uint32_t uni_value = 0;
for (size_t esc_length = 0; esc_length < (esc_char == L'u' ? 4 : 8); esc_length++)
{
if (! is_hex_digit(*p))
{
/* Escape sequence must be done. Complain if we didn't get anything */
if (esc_length == 0)
{
this->fatal_error(_(L"Missing hexadecimal number in Unicode escape"));
}
break;
}
uni_value = uni_value * 16 + hex_to_bin(*p);
p++;
}
/* PCA GNU printf respects the limitations described in ISO N717, about which universal characters "shall not" be specified. I believe this limitation is for the benefit of compilers; I see no reason to impose it in builtin_printf.
If __STDC_ISO_10646__ is defined, then it means wchar_t can and does hold Unicode code points, so just use that. If not defined, use the %lc printf conversion; this probably won't do anything good if your wide character set is not Unicode, but such platforms are exceedingly rare.
*/
if (uni_value > 0x10FFFF)
{
this->fatal_error(_(L"Unicode character out of range: \\%c%0*x"), esc_char, (esc_char == L'u' ? 4 : 8), uni_value);
}
else
{
#if defined(__STDC_ISO_10646__)
this->append_output(uni_value);
#else
this->append_format_output(L"%lc", uni_value);
}
#endif
}
else
{
this->append_format_output(L"%lc", L'\\');
if (*p)
{
this->append_format_output(L"%lc", *p);
p++;
}
}
return p - escstart - 1;
}
static bool is_escape_char(char const *& s, unsigned& result) {
unsigned d1, d2, d3;
if (*s != '\\' || *(s + 1) == 0) {
return false;
}
if (*(s + 1) == 'x' &&
is_hex_digit(*(s + 2), d1) && is_hex_digit(*(s + 3), d2)) {
result = d1*16 + d2;
s += 4;
return true;
}
/* C-standard octal escapes: either 1, 2, or 3 octal digits,
* stopping either at 3 digits or at the first non-digit character.
*/
/* 1 octal digit */
if (is_octal_digit(*(s + 1), d1) && !is_octal_digit(*(s + 2), d2)) {
result = d1;
s += 2;
return true;
}
/* 2 octal digits */
if (is_octal_digit(*(s + 1), d1) && is_octal_digit(*(s + 2), d2) &&
!is_octal_digit(*(s + 3), d3)) {
result = d1 * 8 + d2;
s += 3;
return true;
}
/* 3 octal digits */
if (is_octal_digit(*(s + 1), d1) && is_octal_digit(*(s + 2), d2) &&
is_octal_digit(*(s + 3), d3)) {
result = d1*64 + d2*8 + d3;
s += 4;
return true;
}
switch (*(s + 1)) {
case 'a':
result = '\a';
s += 2;
return true;
case 'b':
result = '\b';
s += 2;
return true;
#if 0
case 'e':
result = '\e';
s += 2;
return true;
#endif
case 'f':
result = '\f';
s += 2;
return true;
case 'n':
result = '\n';
s += 2;
return true;
case 'r':
result = '\r';
s += 2;
return true;
case 't':
result = '\t';
s += 2;
return true;
case 'v':
result = '\v';
s += 2;
return true;
default:
result = *(s + 1);
s += 2;
return true;
}
return false;
}