HP C/iX Library Reference Manual (30026-90004)

Chapter 5 343
HP C/iX Library Function Descriptions
strncmp
strncmp
Compares two strings up to a maximum of n characters and returns an integer result of
the comparison.
Syntax
#include <string.h>
int strncmp(const char * s1 , const char * s2 , size_t n );
Parameters
s1 , s2 Pointers to character strings.
n Specifies the maximum number of characters to compare in both s1 and
s2 .
Return Values
<0 s1 is less than s2 .
=0
s1 and s2 are equal.
>0
s1 is greater than s2 .
Description
In the strncmp function, s1 and s2 are character pointers to the null-terminated character
strings to be compared. strncmp() compares at most
n characters of both strings. Neither
string need be null-terminated if
n is less than or equal to the length of the shorter string.
Example
The following program fragment uses strncmp() to analyze the contents of a file coded
with macros. In this example, a period (.) at the beginning of a line indicates a macro. The
program reads each line of the file and keeps a count of the number of times selected
macros are used, and prints a summary of its findings at the end.
#include <stdio.h>
main(argc, argv)
int argc;
char *argv[ ];
{
char *fgets(), line[100];
FILE *fp;
int nsh, npp, ntp, nrs, nre, npd, nip, nmisc, nlines;
nsh = npp = ntp = nrs = nre = npd = nip = nmisc = nlines = 0;
if(argc != 2) {
fprintf(stderr, "Usage: count file\n");