STRXFRM(3) Library Functions Manual STRXFRM(3) NAME strxfrm, strxfrm_l – transform a string under locale LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <string.h> size_t strxfrm(char *restrict s1, const char *restrict s2, size_t n); #include <string.h> #include <xlocale.h> size_t strxfrm_l(char *restrict s1, const char *restrict s2, size_t n, locale_t loc); DESCRIPTION The strxfrm() function transforms a null-terminated string pointed to by s2 according to the current locale collation if any, then copies the transformed string into s1. Not more than n characters are copied into s1, including the terminating null character added. If n is set to 0 (it helps to determine an actual size needed for transformation), s1 is permitted to be a NULL pointer. Comparing two strings using strcmp() after strxfrm() is equal to comparing two original strings with strcoll(). Although the strxfrm() function uses the current locale, the strxfrm_l() function may be passed a locale directly. See xlocale(3) for more information. RETURN VALUES Upon successful completion, strxfrm() returns the length of the transformed string not including the terminating null character. If this value is n or more, the contents of s1 are indeterminate. SEE ALSO setlocale(3), strcmp(3), strcoll(3), wcsxfrm(3), xlocale(3) STANDARDS The strxfrm() function conforms to ISO/IEC 9899:1990 (“ISO C90”). macOS 15.2 June 4, 1993 macOS 15.2