strxfrm - Transforms string for collation in current locale
Standard C Library (libc.so, libc.a)
const char *s2,
Interfaces documented on this reference page conform to industry standards as follows:
strxfrm(): XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about industry standards and associated tags.
Specifies the destination string. Specifies the string to be transformed. Specifies the maximum number of bytes to store in the transformed string.
The strxfrm() function transforms the string pointed to by the s2 parameter into an internal form suitable for collation and places the result in the address specified by s1. This transformation is performed as appropriate to the LC_COLLATE category of the current locale. When the strcmp() function is applied to two transformed strings, a value greater than, equal to, or less than 0 (zero) is returned. The returned value corresponds to the same value that is returned when the strcoll() function is applied to the same two original transformed strings. The transformed string can be longer than the original string. No more than n characters are placed in the location pointed to by the s1 parameter, including the terminating null character. When n is 0 (zero), the s1 parameter can be a null pointer. When operating on overlapping strings, the behavior of this function is unreliable.
If you are doing multiple comparisons using the same set of text strings, the strxfrm() transformation function in conjunction with the strcmp() function may be more efficient than using the strcoll() collation function because the string is transformed based on the locale tables only once. However, the transformation function must convert all characters in the string for each level of a multi-level collation. In comparison, the collation function stops comparing characters at the first inequality. These efficiency tradeoffs make the most efficient method for a specific application dependent on both the number of repeated comparisons for each string and the contents of each string.
Upon successful completion, the strxfrm() function returns the number of bytes required to store the transformed string (not including the terminating null byte). If this is greater than or equal to the value of the n parameter, which specifies the maximum number of bytes that can be stored in s1, the contents of s1 are indeterminate.
If the following condition occurs, the strxfrm() function sets errno to the corresponding value. The s2 parameter contains codes outside the domain of the collating sequence defined by the current locale.
Functions: setlocale(3), strcoll(3), string(3)/strcmp(3), wcsxfrm(3)
Standards: standards(5) delim off