Predefined macro
This macro performs limited comparison of two strings. It is used to compare strings in ASCII sequence, except that the comparison stops after count characters, or when the first NUL character is encountered, whichever comes first.
This macro behaves like the strncmp function in the ANSI C string library.
Syntax:
char *strncmp
(str1, str2, count)
char *str1;
char *str2;
int count;
where:
str1 Specifies the location in memory of the first byte of a character string.
str2 Specifies the location in memory of the first byte of a character string.
count Specifies the number of characters in each string to compare, unless the NUL character is encountered in either string first.
Return Value
int One of the following:
-1 Indicates that str2 comes after str1 in the machine collating sequences, str1 < str2.
0 Indicates that the two strings are identical in content.
1 Indicates that str1 comes after str2 in the machine collating sequences, str2 < str1.
Rules
Strings do not need to be NUL terminated or fit within the array boundaries since the comparison is limited to the number of stated characters.
Less than count characters are compared if one of the strings is smaller than count characters.
The comparison is always signed, regardless of how the string is declared.