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strxfrm(3)
NAME
  strxfrm - Transforms string for collation in current locale

SYNOPSIS
  #include <string.h>

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

LIBRARY
  Standard C Library (libc)

STANDARDS
  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.

PARAMETERS
  s1  Specifies the destination string.

  s2  Specifies the string to be transformed.

  n   Specifies the maximum number of bytes to store in the transformed
      string.

DESCRIPTION
  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.

NOTES
  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.

RETURN VALUES
  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.

ERRORS
  If the following condition occurs, the strxfrm() function sets errno to the
  corresponding value.

  [EINVAL]
      The s2 parameter contains codes outside the domain of the collating
      sequence defined by the current locale.

SEE ALSO
  Functions: setlocale(3), strcoll(3), string(3), strcmp(3), wcsxfrm(3)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for S

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