int strncmp ( const char * str1, const char * str2, size_t num ); |
<cstring> |
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
- Maximim 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
/* 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) |
