path: root/usr/src/man/man3c/u8_strcmp.3c

'\" te
.\" Copyright (c) 2007, Sun Microsystems Inc. All Rights Reserved.
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.TH u8_strcmp 3C "12 Sep 2007" "SunOS 5.11" "Standard C Library Functions"
.SH NAME
u8_strcmp \- UTF-8 string comparison function
.SH SYNOPSIS
.LP
.nf
#include <sys/u8_textprep.h>

\fBint\fR \fBu8_strcmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR,
     \fBint\fR \fIflag\fR, \fBsize_t\fR \fIversion\fR, \fBint *\fR\fIerrnum\fR);
.fi

.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIs1\fR, \fIs2\fR\fR
.ad
.RS 13n
.rt  
Pointers to null-terminated UTF-8 strings
.RE

.sp
.ne 2
.mk
.na
\fB\fIn\fR\fR
.ad
.RS 13n
.rt  
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.
.RE

.sp
.ne 2
.mk
.na
\fB\fIflag\fR\fR
.ad
.RS 13n
.rt  
The possible comparison options constructed by a bit-wise-inclusive-OR of the
following values:
.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_CS\fR\fR
.ad
.sp .6
.RS 4n
Perform case-sensitive string comparison. This is the default.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_CI_UPPER\fR\fR
.ad
.sp .6
.RS 4n
Perform case-insensitive string comparison based on Unicode upper case
converted results of \fIs1\fR and \fIs2\fR.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_CI_LOWER\fR\fR
.ad
.sp .6
.RS 4n
Perform case-insensitive string comparison based on Unicode lower case
converted results of \fIs1\fR and \fIs2\fR.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_NFD\fR\fR
.ad
.sp .6
.RS 4n
Perform string comparison after \fIs1\fR and \fIs2\fR have been normalized by
using Unicode Normalization Form D.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_NFC\fR\fR
.ad
.sp .6
.RS 4n
Perform string comparison after \fIs1\fR and \fIs2\fR have been normalized by
using Unicode Normalization Form C.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_NFKD\fR\fR
.ad
.sp .6
.RS 4n
Perform string comparison after \fIs1\fR and \fIs2\fR have been normalized by
using Unicode Normalization Form KD.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_STRCMP_NFKC\fR\fR
.ad
.sp .6
.RS 4n
Perform string comparison after \fIs1\fR and \fIs2\fR have been normalized by
using Unicode Normalization Form KC.
.RE

Only one case-sensitive or case-insensitive option is allowed. Only one Unicode
Normalization option is allowed.
.RE

.sp
.ne 2
.mk
.na
\fB\fIversion\fR\fR
.ad
.RS 13n
.rt  
The version of Unicode data that should be used during comparison. The
following values are supported:
.sp
.ne 2
.mk
.na
\fB\fBU8_UNICODE_320\fR\fR
.ad
.sp .6
.RS 4n
Use Unicode 3.2.0 data during comparison.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_UNICODE_500\fR\fR
.ad
.sp .6
.RS 4n
Use Unicode 5.0.0 data during comparison.
.RE

.sp
.ne 2
.mk
.na
\fB\fBU8_UNICODE_LATEST\fR\fR
.ad
.sp .6
.RS 4n
Use the latest Unicode version data available, which is Unicode 5.0.0.
.RE

.RE

.sp
.ne 2
.mk
.na
\fB\fIerrnum\fR\fR
.ad
.RS 13n
.rt  
A non-zero value indicates that an error has occurred during comparison. The
following values are supported:
.sp
.ne 2
.mk
.na
\fB\fBEBADF\fR\fR
.ad
.RS 10n
.rt  
The specified option values are conflicting and cannot be supported.
.RE

.sp
.ne 2
.mk
.na
\fB\fBEILSEQ\fR\fR
.ad
.RS 10n
.rt  
There was an illegal character at \fIs1\fR, \fIs2\fR, or both.
.RE

.sp
.ne 2
.mk
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 10n
.rt  
There was an incomplete character at \fIs1\fR, \fIs2\fR, or both.
.RE

.sp
.ne 2
.mk
.na
\fB\fBERANGE\fR\fR
.ad
.RS 10n
.rt  
The specified Unicode version value is not supported.
.RE

.RE

.SH DESCRIPTION
.sp
.LP
The \fBu8_stcmp()\fR function internally processes UTF-8 strings pointed to by
\fIs1\fR and \fIs2\fR based on the corresponding version of the Unicode
Standard and other input arguments and compares the result strings in
byte-by-byte, machine ordering.
.sp
.LP
When multiple comparison options are specified, Unicode Normalization is
performed after case-sensitive or case-insensitive processing is performed.
.SH RETURN VALUES
.sp
.LP
The \fBu8_strcmp()\fR function returns an integer greater than, equal to, or
less than 0 if the string pointed to by \fIs1\fR is greater than, equal to, or
less than the string pointed to by \fIs2\fR, respectively.
.sp
.LP
When \fBu8_strcmp()\fR detects an illegal or incomplete character, such
character causes the function to set \fIerrnum\fR to indicate the error.
Afterward, the comparison is still performed on the resultant strings and a
value based on byte-by-byte comparison is always returned.
.SH EXAMPLES
.LP
\fBExample 1 \fRPerform simple default string comparison.
.sp
.in +2
.nf
#include <sys/u8_textprep.h>

int
docmp_default(const char *u1, const char *u2) {
    int result;
    int errnum;

    result = u8_strcmp(u1, u2, 0, 0, U8_UNICODE_LATEST, &errnum);
    if (errnum == EILSEQ)
        return (-1);
    if (errnum == EINVAL)
        return (-2);
    if (errnum == EBADF)
        return (-3);
    if (errnum == ERANGE)
        return (-4);
.fi
.in -2

.LP
\fBExample 2 \fRPerform upper case based case-insensitive comparison with
Unicode 3.2.0 date.
.sp
.in +2
.nf
#include <sys/u8_textprep.h>

int
docmp_caseinsensitive_u320(const char *u1, const char *u2) {
    int result;
    int errnum;

    result = u8_strcmp(u1, u2, 0, U8_STRCMP_CI_UPPER,
        U8_UNICODE_320, &errnum);
    if (errnum == EILSEQ)
        return (-1);
    if (errnum == EINVAL)
        return (-2);
    if (errnum == EBADF)
        return (-3);
    if (errnum == ERANGE)
        return (-4);

    return (result);
}
.fi
.in -2

.LP
\fBExample 3 \fRPerform Unicode Normalization Form D.
.sp
.LP
Perform Unicode Normalization Form D and upper case based case-insensitive
comparison with Unicode 3.2.0 date.

.sp
.in +2
.nf
#include <sys/u8_textprep.h>

int
docmp_nfd_caseinsensitive_u320(const char *u1, const char *u2) {
    int result;
    int errnum;

    result = u8_strcmp(u1, u2, 0,
        (U8_STRCMP_NFD|U8_STRCMP_CI_UPPER), U8_UNICODE_320,
        &errnum);
    if (errnum == EILSEQ)
        return (-1);
    if (errnum == EINVAL)
        return (-2);
    if (errnum == EBADF)
        return (-3);
    if (errnum == ERANGE)
        return (-4);

    return (result);
}
.fi
.in -2

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelMT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBu8_textprep_str\fR(3C), \fBu8_validate\fR(3C), \fBattributes\fR(5),
\fBu8_strcmp\fR(9F), \fBu8_textprep_str\fR(9F), \fBu8_validate\fR(9F)
.sp
.LP
The Unicode Standard (http://www.unicode.org)