Jonathan Saggau's Blog: shhhhh, don't tell anybody

pyobjc is nice for introspection of cocoa objects. :)

NSString has some private regexp methods. Not so surprising, given that coredata lets us validate strings against regular expressions... As always with hidden functionality in apple classes: this might not always work the way you expect and might not even exist in past / future versions of the os...etc.

(UPDATE: this doesn't really behave as I would have expected. See code in the comments that does).

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    NSString *test = [[NSString alloc] initWithString:@"hello world"];

    NSString *regexp = [[NSString alloc] initWithString:@"hello*"];

    if ([test matchesPattern:regexp]) {

        NSLog(@"%@ Matches %@", test, regexp);

    } else {

        NSLog(@"%@ Does not match %@", test, regexp);

    }

    

    [test release];

    [regexp release];

    [pool release];

    return 0;

}

[Session started at 2006-08-27 15:01:02 -0400.]
2006-08-27 15:01:02.975 nsstringtest[2239] hello world Matches hello*

nsstringtest has exited with status 0.

#import

BOOL stringMatchesPattern(NSString * string, NSString * regex)
{
NSString *testRegex = [[NSString alloc] initWithFormat:@"SELF MATCHES '%@'", regex];
NSPredicate *regexPredicate = [NSPredicate predicateWithFormat:testRegex];
[testRegex release];// the predicate has retained testRegex
return ([regexPredicate evaluateWithObject:string]);
}

BOOL stringIsIPv4Address(NSString * string)
{
return(stringMatchesPattern(string, @"(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"));
}

int main (int argc, const char * argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSString *test = [[NSString alloc] initWithString:@"123.255.255.255"];
NSString *regexp = [[NSString alloc] initWithString:@"(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"];
if (stringMatchesPattern(test, regexp)) {
NSLog(@"%@ Matches %@", test, regexp);
} else {
NSLog(@"%@ Does not match %@", test, regexp);
}
if (stringIsIPv4Address(@"192.168.1.1")) {
NSLog(@"It works");
} else {
NSLog(@"Broken");
}
[test release];
[regexp release];
[pool release];
return 0;
}

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