strncmp

Compares not more than maxchar characters of two ASCII character strings and returns a negative, 0, or positive integer, indicating that the ASCII values of the individual characters in the first string are less than, equal to, or greater than the values in the second string.

Format

#include  <string.h>

int strncmp  (const char *str_1, const char
             *str_2, size_t maxchar);

Arguments

str_1, str_2: Pointers to character strings.
maxchar: The maximum number of characters (beginning with the first) to search in both str_1 and str_2. If maxchar is 0, no comparison is performed and 0 is returned (the strings are considered equal).

Description

This function compares no more than maxchar characters from the string pointed to by str_1 to the string pointed to by str_2. The strings are compared until a null character is encountered, the strings differ, or maxchar is reached. Characters that follow a difference or a null character are not compared.

Return Values

< 0 Indicates that str_1 is less than str_2.

= 0 Indicates that str_1 equals str_2.

> 0 Indicates that str_1 is greater than str_2.

Examples

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

$ create tmp.c
    main()
    {
        printf( "%d\n", strncmp("abcde", "abc", 3));
    }
    $ cc tmp.c

When linked and executed, this example returns 0, because the first 3 characters of the 2 strings are equal:

$ run tmp
        0

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

$ create tmp.c
    main()
    {
        printf( "%d\n", strncmp("abcde", "abc", 4));
    }
    $ cc tmp.c
```
When linked and executed, this example returns a value greater than 0 because the first 4 characters of the 2 strings are not equal (The "d" in the first string is not equal to the null character in the second):
```
$ run tmp
        100
```

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