u8_strcmp(9F) Kernel Functions for Drivers u8_strcmp(9F)
NAME
u8_strcmp - UTF-8 string comparison function
SYNOPSIS
#include <sys/sunddi.h>
int u8_strcmp(const char *s1, const char *s2, size_t n,
int flag, size_t unicode_version, int *errno);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI)
PARAMETERS
s1, s2 Pointers to null-terminated UTF-8 strings
n The maximum number of bytes to be compared. If 0, the comparison is performed until either or both of the strings are
examined to the string terminating null byte.
flag The possible comparison options constructed by a bit-wise-inclusive-OR of the following values:
U8_STRCMP_CS
Perform case-sensitive string comparison. This is the default.
U8_STRCMP_CI_UPPER
Perform case-insensitive string comparison based on Unicode upper case converted results of s1 and s2.
U8_STRCMP_CI_LOWER
Perform case-insensitive string comparison based on Unicode lower case converted results of s1 and s2.
U8_STRCMP_NFD
Perform string comparison after s1 and s2 have been normalized by using Unicode Normalization Form D.
U8_STRCMP_NFC
Perform string comparison after s1 and s2 have been normalized by using Unicode Normalization Form C.
U8_STRCMP_NFKD
Perform string comparison after s1 and s2 have been normalized by using Unicode Normalization Form KD.
U8_STRCMP_NFKC
Perform string comparison after s1 and s2 have been normalized by using Unicode Normalization Form KC.
Only one case-sensitive or case-insensitive option is allowed. Only one Unicode Normalization option is allowed.
unicode_version The version of Unicode data that should be used during comparison. The following values are supported:
U8_UNICODE_320
Use Unicode 3.2.0 data during comparison.
U8_UNICODE_500
Use Unicode 5.0.0 data during comparison.
U8_UNICODE_LATEST
Use the latest Unicode version data available, which is Unicode 5.0.0.
errno A non-zero value indicates that an error has occurred during comparison. The following values are supported:
EBADF The specified option values are conflicting and cannot be supported.
EILSEQ There was an illegal character at s1, s2, or both.
EINVAL There was an incomplete character at s1, s2, or both.
ERANGE The specified Unicode version value is not supported.
DESCRIPTION
After proper pre-processing, the u8_strcmp() function compares two UTF-8 strings byte-by-byte, according to the machine ordering defined by
the corresponding version of the Unicode Standard.
When multiple comparison options are specified, Unicode Normalization is performed after case-sensitive or case-insensitive processing is
performed.
RETURN VALUES
The u8_strcmp() function returns an integer greater than, equal to, or less than 0 if the string pointed to by s1 is greater than, equal
to, or less than the string pointed to by s2, respectively.
When u8_strcmp() detects an illegal or incomplete character, such character causes the function to set errno to indicate the error. After-
ward, the comparison is still performed on the resultant strings and a value based on byte-by-byte comparison is always returned.
CONTEXT
The u8_strcmp() function can be called from user or interrupt context.
EXAMPLES
Example 1 Perform simple default string comparison.
#include <sys/sunddi.h>
int
docmp_default(const char *u1, const char *u2) {
int result;
int ;
result = u8_strcmp(u1, u2, 0, 0, U8_UNICODE_LATEST, &errno);
if (errno == EILSEQ)
return (-1);
if (errno == EINVAL)
return (-2);
if (errno == EBADF)
return (-3);
if (errno == ERANGE)
return (-4);
Example 2 Perform upper case based case-insensitive comparison with Unicode 3.2.0 date.
#include <sys/sunddi.h>
int
docmp_caseinsensitive_u320(const char *u1, const char *u2) {
int result;
int errno;
result = u8_strcmp(u1, u2, 0, U8_STRCMP_CI_UPPER,
U8_UNICODE_320, &errno);
if (errno == EILSEQ)
return (-1);
if (errno == EINVAL)
return (-2);
if (errno == EBADF)
return (-3);
if (errno == ERANGE)
return (-4);
return (result);
}
Example 3 Perform Unicode Normalization Form D.
Perform Unicode Normalization Form D and uppercase-based case-insensitive comparison with Unicode 3.2.0 date.
#include <sys/sunddi.h>
int
docmp_nfd_caseinsensitive_u320(const char *u1, const char *u2) {
int result;
int errno;
result = u8_strcmp(u1, u2, 0,
(U8_STRCMP_NFD|U8_STRCMP_CI_UPPER), U8_UNICODE_320,
&errno);
if (errno == EILSEQ)
return (-1);
if (errno == EINVAL)
return (-2);
if (errno == EBADF)
return (-3);
if (errno == ERANGE)
return (-4);
return (result);
}
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
SEE ALSO
u8_validate(3C), u8_textprep_str(3C), u8_validate(3C), attributes(5), u8_textprep_str(9F), u8_validate(9F), uconv_u16tou32(9F)
The Unicode Standard (http://www.unicode.org)
SunOS 5.11 18 Sep 2007 u8_strcmp(9F)