strcoll - Compare Strings Using Collation Rules

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

string1

string2

string1

string2

string1

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"
   ****************************************************************************/
}

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