Syntax

#include <string.h>
int strcoll(const char *string1, const char *string2);

strcoll compares the string pointed to by string1 against the string pointed to by string2, both interpreted according to the information in the LC_COLLATE category of the current locale.

strcoll differs from the strcmp function. strcoll performs a comparison between two character strings based on language collation rules as controlled by the LC_COLLATE category. In contrast, strcmp performs a character to character comparison.

• If a string will be collated many times, as when inserting an entry into a sorted list, strxfrm followed by strcmp can be more efficient.
  
• If only comparison for strict equality is desired, strcmp should be used, since it is more efficient.

strcoll returns an integer value indicating the relationship between the strings, as listed below: compact break=fit.

Value

Meaning
Less than 0
string1 is less than string2
0
string1 is equivalent to string2
Greater than 0
string1 is greater than string2

Note:

• strcoll might need to allocate additional memory to perform the comparison algorithm specified in the LC_COLLATE. If the memory request cannot be satisfied (by malloc), then strcoll fails.

• If the locale supports double-byte characters (MB_CUR_MAX specified as 2), strcoll validates the multibyte characters. strcoll fails if the string contains invalid multibyte characters.

This example compares the two strings passed to main.

#include <stdio.h>#include <string.h>

int main(int argc,char **argv)
{
   int result;

   if (argc != 3) {
      printf("Usage: %s string1 string2\n", argv[0]);
   }
   else {
      result = strcoll(argv[1], argv[2]);
      if (0 == result)
         printf("\"%s\" is identical to \"%s\"\n", argv[1], argv[2]);
      else
         if (result < 0)
            printf("\"%s\" is less than \"%s\"\n", argv[1], argv[2]);
         else
            printf("\"%s\" is greater than \"%s\"\n", argv[1], argv[2]);
   }
   return 0;

   /****************************************************************************
      If the program is passed the following arguments:

      "firststring" "secondstring"

      The output should be:

      "firststring" is less than "secondstring"
   ****************************************************************************/
}

• setlocale
  
• strcmp
  
• strcmpi
  
• strncmp
  
• wcscoll

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