strncmp


function
<cstring> 
int strncmp ( const char * str1, const char * str2, size_t num );

Compare characters of two strings

Compares up to num characters of the C string str1 to those of the C string str2.
This function starts comparing the first character of each string. If they are equal to each other, it continues with the following pairs until the characters differ, until a terminating null-character is reached, or until num characters match in both strings, whichever happens first.

Parameters

str1
C string to be compared.
str2
C string to be compared.
num
Maximum number of characters to compare.


Return Value

Returns an integral value indicating the relationship between the strings:
A zero value indicates that the characters compared in both strings are all equal.
A value greater than zero indicates that the first character that does not match has a greater value in str1 than in str2; And a value less than zero indicates the opposite.

Example

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/* strncmp example */
#include <stdio.h>
#include <string.h>

int main ()
{
  char str[][5] = { "R2D2" , "C3PO" , "R2A6" };
  int n;
  puts ("Looking for R2 astromech droids...");
  for (n=0 ; n<3 ; n++)
    if (strncmp (str[n],"R2xx",2) == 0)
    {
      printf ("found %s\n",str[n]);
    }
  return 0;
}


Output:

Looking for R2 astromech droids...
found R2D2
found R2A6


See also

strcmp Compare two strings (function)
memcmp Compare two blocks of memory (function)
strrchr Locate last occurrence of character in string (function)
strspn Get span of character set in string (function)