Strcmp

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In the programming language C, strcmp is a function in the C standard library (in the string.h header file) that compares two C strings.

int strcmp (const char *s1, const char *s2)

strcmp returns 0 when the strings are equal, a negative integer when s1 is less than s2, or a positive integer if s1 is greater than s2, according to the lexicographical order.

A variant of strcmp exists called strncmp that only compares the strings up to a certain point.

[edit] Example

 #include <stdio.h>
 #include <string.h>
 
 int main (int argc, char **argv)
 {
     if (argc < 3)
     {
         fprintf (stderr, "This program takes 2 arguments.\n");
         return 1;
     }
 
     int v = strcmp (argv[1], argv[2]);
 
     if (v < 0)
     {
         printf ("%s is less than %s.\n", argv[1], argv[2]);
     }
     else if (v == 0)
     {
         printf ("%s equals %s.\n", argv[1], argv[2]);
     }
     else if (v > 0)
     {
         printf ("%s is greater than %s.\n", argv[1], argv[2]);
     }
 
     return 0;
 }

The above code is a working sample that prints whether the first argument is less than, equal to or greater than the second.