parseSshConfig: My first ever from-scratch Objective-C program. Parses the contents of your .ssh config file into a dictionary variable. To be used in a future project. -- UPDATED: 2012-09-27 00:13:12 - Rewrote parsing logic to be much more flexible!

gistfile1.m

//
//  main.m
//  parseSshConfig
//
//  "A very simple .ssh config file parser."
//
//  Created by Justin Swanson on 8/17/12.
//  Copyright (c) 2012 h4xful.net. All rights reserved.
//

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
        
        // insert code here...
        NSLog(@"--- SSH PARSER ---");

        NSString *configFile = @"~/.ssh/config";
        configFile = [configFile stringByExpandingTildeInPath];
        NSFileManager *fileMgr = [[NSFileManager alloc] init];

        if ([fileMgr fileExistsAtPath: configFile]) {
            NSLog(@"The file exists!");
            // Get file contents into fh.
            NSString *fh = [NSString stringWithContentsOfFile:configFile encoding:NSUTF8StringEncoding error:nil];
            // Initialize our server list as an empty dictionary variable.
            NSMutableDictionary *servers = [NSMutableDictionary dictionaryWithObjects:nil forKeys:nil];
            // Initialize our placeholder variable for the current server's host value.
            NSString *host = @"";

            // Loop through each line and parse the file.
            for (NSString *line in [fh componentsSeparatedByString:@"\n"]) {
                // Find the position of the first space in the line.
                NSRange spacePos = [line rangeOfString:@" "];
                // If no space is found, skip this line.
                if (spacePos.location == NSNotFound) {
                    continue;
                }
                // Grab the key and the value.
                NSString *key = [line substringToIndex:spacePos.location];
                NSString *value = [line substringFromIndex:spacePos.location+1];
                // Add the values to the servers dictionary object.
                // ... if key is "Host", establish a new sub-dictionary object.
                if ([key isEqualToString:@"Host"]) {
                    host = value;
                    [servers setObject:[NSMutableDictionary dictionaryWithObjects:nil forKeys:nil] forKey:host];
                }
                // Now setting the value
                [[servers objectForKey:host] setObject:value forKey:key];
            }

            // Now to walk through the server list and see the data we found
            for (NSString *line in servers) {
                NSLog(@"Now listing parameters for server named: %@", line);
                for (NSString *embeddedLine in [servers objectForKey:line]) {
                    NSLog(@"Parameter %@: %@", embeddedLine, [[servers objectForKey:line] objectForKey:embeddedLine]);
                }
                NSLog(@" "); // blank line on the terminal
            }
        }
        else {
            NSLog(@"You don't have a .ssh config file!");
        }
    }
    return 0;
}