James (MrGeckosMedia.com), joined by, Eduardo (MegaEduX.com), and Nick, explains libraries and frameworks.

11:56

Example code from episode.
Libraries
Libraries included, /usr/lib/libcrypto.dylib and /usr/lib/libssl.dylib
#import <Foundation/Foundation.h>#import <openssl/evp.h>

int main (int argc, const char * argv[]) {NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];NSString *string = @"Hello";OpenSSL_add_all_algorithms();unsigned char outbuf[EVP_MAX_MD_SIZE];unsigned int templen, inlen = [string length];const char *input = [string UTF8String];EVP_MD_CTX ctx;const EVP_MD *digest = EVP_md5();if(!digest) {NSLog(@"cannot get digest with name MD5");return 1;}EVP_MD_CTX_init(&ctx);EVP_DigestInit(&ctx,digest);if(!EVP_DigestUpdate(&ctx,input,inlen)) {NSLog(@"EVP_DigestUpdate() failed!");EVP_MD_CTX_cleanup(&ctx);return 1; }if (!EVP_DigestFinal(&ctx, outbuf, &templen)) {NSLog(@"EVP_DigesttFinal() failed!");EVP_MD_CTX_cleanup(&ctx);return 1;}EVP_MD_CTX_cleanup(&ctx);NSMutableString *md5 = [NSMutableString string];for (int i=0; i<templen; i++) {[md5 appendFormat:@"%x", outbuf[i]];}NSLog(@"MD5 of %@ is %@", string, md5);[pool drain];return 0;}Frameworks
Frameworks included, AddressBook.framework
#import <Foundation/Foundation.h>#import <AddressBook/AddressBook.h>

int main (int argc, const char * argv[]) {NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];ABAddressBook *addressBook = [ABAddressBook sharedAddressBook];NSArray *people = [addressBook people];for (int i=0; i<[people count]; i++) {ABPerson *person = [people objectAtIndex:i];NSString *firstName = [person valueForProperty:kABFirstNameProperty];NSString *lastName = [person valueForProperty:kABLastNameProperty];NSString *name = nil;if (firstName!=nil) {name = firstName;if (lastName!=nil)name = [name stringByAppendingFormat:@" %@", lastName];}if (name!=nil)NSLog(@"Person named: %@", name);}[pool drain];return 0;}
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