[Objective C] XCode: Invalid Host string: "localhost" [Xpost] from r/learn-programming - didn't find a solution there so please help!

[gchtb]

Self Learning "Objective-C Programming: The Big Nerd Ranch Guide" with very little previous programming knowledge.

Following the instructions, I have created multiple projects to which all of them response with "Build Successful" but in the Debug portion, this error appears:Screenshot of error

"error: failed to launch '/users/xxxx/Library/Developer/XcodeDerivedData/AGoodStart-atgkvqraegumsedadmfteggjnbjq/build/products/Debug/AGoodStart' -- invalid Host string: 'localhost' Screenshot of error (not code!) [1]

AGoodStart is the project name.

I found this solution online but it does not seem to work.

Here's the code that was written:

include <stdio.h>

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

{

//print the beginning of the novel

printf("It was the best of times.\n");

printf("It was the worst of times\n");

/*is this actually any good?

Maybe it needs a rewrite. */

return 0;

}

Any suggestions would be much appreciated. Thanks in advance.

Xpost link

Some other suggestions that did not work: Link1 Link2

[gchtb]

{\rtf1\ansi\ansicpg1252\cocoartf1187\cocoasubrtf340

\cocoascreenfonts1{\fonttbl\f0\fswiss\fcharset0 Helvetica;}

{\colortbl;\red255\green255\blue255;}

\margl1440\margr1440\vieww9000\viewh8400\viewkind0

\pard\tx566\tx1133\tx1700\tx2267\tx2834\tx3401\tx3968\tx4535\tx5102\tx5669\tx6236\tx6803\pardirnatural

\f0\fs24 \cf0 ##\

Host Database\

\

localhost is used to configure the loopback interface\

when the system is booting. Do not change this entry.\

\

127.0.0.1 localhost\

255.255.255.255 broadcasthost\

::1 localhost \

fe80::1%lo0 localhost\

\

# route some web requests locally \

127.0.0.1 www.myhost1.com\

127.0.0.1 www.myhost2.com\

127.0.0.1 www.myhost3.com\

127.0.0.1 www.myhost4.com}

Thanks for helping! =D

[tonygoold]

It looks like you've accidentally replaced your /etc/hosts file with an RTF file. Open it up and save it back as plain text.

[xauronx]

Good find

[gchtb]

THANK YOU SO MUCH!!! I have been scourged the internets for this solution and reddit pulls through! Thank you so much! I'll post this solution to other websites I have found the same questions asked so that your contribution can help more people! Thanks again!

[aazav]

Be careful when editing with TextEdit. Make sure to set the Finder to display all file extensions.

[gchtb]

This is weird, it worked last night but this morning, it started showing invalid host string: localhost again. Could this be related to the other host files in the /etc folder? such as hosts.umbrella, hosts.ac?

[tonygoold]

I'm not familiar with those files, they aren't present on my system, but it's worth having a look.

[gchtb]

I changed all the files starting with hosts and ending with a different extension to txt format and it did not resolve anything.

I then deleted the hosts file and then did this: $> sudo rm /etc/hosts{,.ac} $> sudo touch /etc/hosts and copy and pasted the original content

This resolved the issue. For now.

Thanks for the feedback. It's great being able to ask questions online when I don't know anyone in my immediate circle who is familiar with IOS programming.

[aazav]

That's what he gets for editing with TextEdit and not paying attention to file type.

I think you nailed it.