STRXFRM(3C) Standard C Library Functions STRXFRM(3C)


strxfrm, strxfrm_l - string transformation


#include <string.h>

size_t strxfrm(char *restrict s1, const char *restrict s2, size_t n);

size_t strxfrm_l(char *restrict s1, const char *restrict s2, size_t n,
locale_t loc);


The strxfrm() function transforms the string pointed to by s2 and places
the resulting string into the array pointed to by s1. The transformation
is such that if strcmp(3C) is applied to two transformed strings, it
returns a value greater than, equal to or less than 0, corresponding to
the result of strcoll(3C) applied to the same two original strings. No
more than n bytes are placed into the resulting array pointed to by s1,
including the terminating null byte. If n is 0, s1 is permitted to be a
null pointer. If copying takes place between objects that overlap, the
behavior is undefined.

The strxfrm() function does not change the setting of errno if

Since no return value is reserved to indicate an error, an application
wishing to check for error situations should set errno to 0, then call
strxfrm(), then check errno.

The strxfrm_l() functions behaves identically to the function strxfrm(),
except instead of operating in the current locale it operates in the
locale specified by the argument loc.


Upon successful completion, strxfrm() returns the length of the
transformed string (not including the terminating null byte). If the
value returned is n or more, the contents of the array pointed to by s1
are indeterminate.

On error, strxfrm() may set errno but no return value is reserved to
indicate the error.


The transformation function is such that two transformed strings can be
ordered by strcmp(3C) as appropriate to collating sequence information in
the locale (category LC_COLLATE).

The fact that when n is 0, s1 is permitted to be a null pointer, is
useful to determine the size of the s1 array prior to making the


Example 1: A sample of using the strxfm() function.

The value of the following expression is the size of the array needed to
hold the transformation of the string pointed to by s.

1 + strxfrm(NULL, s, 0);


collation database for locale


See attributes(5) for descriptions of the following attributes:

|CSI | Enabled |
|Interface Stability | Standard |
|MT-Level | MT-Safe |


localedef(1), newlocale(3C), setlocale(3C), strcmp(3C), strcoll(3C),
uselocale(3C), wscoll(3C), attributes(5), environ(5), standards(5)

June 21, 2014 STRXFRM(3C)