I'm a noob to Xcode and am reading the Big Nerd Ranch book and its asking me to do example programs in simple C to get me familiar with the language, however its asked me to create a program that calls a method from main and passes an int and does a square calculation and the printf to defog screen. Here is the program:-
#include <stdio.h>
void doTheMath(int numberToSquare)
{
int numberSquared = numberToSquare * numberToSquare;
printf("%d squared is %d\n",numberToSquare,numberSquared);
}
int main(int argc, const char * argv[])
{
doTheMath(5);
return 0;
}
As you can see I am passing the value 5 to the method and it prints 25 on screen when i run the code. IF I then change 5 to 15 to get it to write out a different value, it doesn't. It still writes out 5 squared, not 25 squared.
In debug and step through the value is wrong and isn't changed.
I've closed the project and Xcode and still it doesn't work all of the time and then sometimes it does reflect the changed value.
The project Type is an OSX application / command-line tool. The project is stored on my NAS.
Your code is correct and when I test it in Xcode and change the 5 to 15 and run it, I get the correct answer returned. Make sure you save your file after you make the change, and you could also try to clean your project (Product > Clean).
Sometimes Xcode just does strange things . . .
Related
I've recently started exploring and reading about Microchip's PIC32 MCUs, most specifically for motor control. I had some job done over the years but was a long while and haven't used the IDE with evaluation board since university years. Been using Arduino-compatible boards since or boards, compatible with the Arduino IDE.
So I'm running MPLAB X IDE v6.05 with the latest XC32 Compiler.
My Development board is DT100113 Curiosity Pro board, utilizing PIC32MK0512MCJ064 MCU and an on-board PicKit4 (PKoB4) for programming/debugging/serial connection purposes.
What I try to do is light up the two user LEDs on pins RA10 and RE13 respectively.
As I begin with creating new project, select my device, my program/debug tool and give my project a name, next step is to create a new main.c file.
I create the file and write the following:
#include <stdio.h>
#include <stdlib.h>
#include <xc.h>
int main(int argc, char** argv) {
//Define corresponding port bits as outputs (0 = output, 1 = input).
TRISAbits.TRISA10 = 0;
TRISEbits.TRISE13 = 0;
//Latch the outputs to HIGH (1) and hold.
while(1)
{
LATAbits.LATA10 = 1;
LATEbits.LATE13 = 1;
}
return (EXIT_SUCCESS);
}
When I build and run it - nothing happens. Build is successful, connected to programmer, erase/flash device OK, but nothing with the LEDs.
I think I'm missing the #pragma directives (read about that it must be defined first prior anything else), but am unaware on how to set configuration bits (used peripherals, internal clock speed, etc.).
Any pointers to how-to articles, posts, etc. will be highly appreciated. I was not able to find step-by-step tutorial for my development board so far :((
Thank you in advance!
Cheers,
Iliyan
I tried creating a new project, it compiled and ran, but the LEDs were not lit.
Obviously was missing some vital parts in the code.
Application software examples and driver libraries are included as part of the MPLAB Harmony V3 Framework. Add Harmony to 'Embedded' under the 'Tools' tab of the MPLAB IDE.
I just started doing some competitive programmning in objective C. There's a problem which I'm facing, most sites start with main.m
int main(int argc, char * argv[]) {
#autoreleasepool {
}
}
I somehow learned how to get input and use it. But today I tried a differnt work where
void main()
{
}
when I tried scanf("%s",str) though I could read the first line of input. But I don't know how to start and how to get rest of lines.
I want to lean more about console input/output in iOS. Any help will be much appreciated?
What you need is a bit of a tutorial
If you right click any data structure for instance there'l be a first option "print description" another option with your code : NSLog(name of variable); for e.g for an array : NSLog(#"%#",myArray);
Lastly,Typing po myarray in the right half of the console (under lldb) would print out myArray's contents
Hope this helps! Cheers
I am using VerificationController.m provided by Raywenderlich for validating receipts for in ap purchase. It is working fine for XCode5 but in XCode6 it is giving number of errors. probably due to C++ code like:
Missing Code for Method declaration
#end must appear in objective-c
context Conflicting types for 'checkReiptSecurity'
can anyone tell me what is needed to be done ?
Edit : Here are errors screenshot
Have you fixed this? I was running in to the exact same problem so I'll leave my fix here for anyone that comes looking. It turns out in newer versions of Xcode you aren't allowed to put C/C++ code in objective-C context anymore. So I moved the declarations for unsigned int iTS_intermediate_der_len, unsigned char iTS_intermediate_der[], char* base64_encode(const void* buf, size_t size), and void * base64_decode(const char* s, size_t * data_len) to the top of the file, above the #implementation tag.
Have you downloaded sample code? I have downloaded sample code and its working fine at my side. It seems that you have missed or added an extra braket } or { in your code.
May be this happened when you was trying to comment this code [UIDevice currentDevice].uniqueIdentifier; because originally this line produce an error.
I believe ive looked at every article related to keyboard input, but still cant get it to work. ALl i want is a output, using NSLog everytime i hit a key, in the app or not. Im currently using xcode 5. Ive tried many snippets of code such as
[NSEvent addGlobalMonitorForEventsMatchingMask:NSKeyDownMask handler:^(NSEvent *event)
NSLog(#"%#",event.characters);
and im not sure where to put his code. Do i put it in the main function like this
#import <Foundation/Foundation.h>
#import <appkit/NSEvent.h>
int main(int argc, char * argV[]) {
#autoreleasepool{
[NSEvent addGlobalMonitorForEventsMatchingMask:NSKeyDownMask handler:^(NSEvent *event)
NSLog(#"%#",event.characters);
}
}
Clearly im new to objective-C, and i dont plan on continuing with it unless i can get keyboard input to work. Ive tried tutorials, snippets from keyloggers, and the mac dev forums. Thanks.
Your code is pretty close but you're getting hung up on block syntax. Blocks are very powerful and useful, but the syntax is truly awful and I still struggle with it 2 years after starting to work with them. Blocks are much less readable than C function pointers, and that's saying a lot.
It should look like this:
int main(int argc, char * argV[])
{
#autoreleasepool
{
[NSEvent addGlobalMonitorForEventsMatchingMask: NSKeyDownMask
handler: ^(NSEvent *event)
{
NSLog(#"%#",event.characters);
}
];
}
}
I put all the opening and closing braces on separate lines for clarity. A block needs to be enclosed in braces, and you were missing braces, as well as the closing bracket on your call to addGlobalMonitorForEventsMatchingMask:handler:
BTW, it's very unusual to change the main() function on a Mac or iOS program. Usually you leave that alone, and then set up an application object, set up a delegate, and put your custom code in the app delegate.
You should start of using the normal Cocoa design patterns for applications, and not try to toss them.
If you want to work with main() in C style you should think about creating a command line tool intend of an interactive application. You're going to set yourself up for failure if you don't follow the standard patterns. There's just too many ways to get things wrong.
Your main is missing the housekeeping needed to create a working iOS or Mac application
I have three question for you, all related to dyld :)
I have been using this dyld man page as a basis. I have compiled the following code and successfully executed the binary on my jailbroken device.
#include <stdio.h>
#include <mach-o/dyld.h>
int main(int argc, const char* argv[]) {
uint32_t image_count, i;
image_count = _dyld_image_count();
for (i = 0; i < image_count; i++) {
printf("%s\n", _dyld_get_image_name(i));
}
return 0;
}
I thought that these functions let me find all the shared libraries that are loaded in my program's address-space. On my mac, the output is pretty straightforward: It shows the paths to all the libraries that are currently loaded in memory. On my iPhone the output is nearly the same - i also get filepaths - but there are no files at the specified location. (On my mac on the other hand, i can locate the files!)
This is a sample line from the output:
/usr/lib/system/libdyld.dylib
According to ls, iFile and all the other tools i've used, this directory (/usr/lib/system/) is empty. Why? Where are those files?
Another thing i'd like to know is: Is it possible to locate a library in memory? From what offset to what offset the library is mapped into memory? I think i know how to find the beginning but i have no idea how to find the end of the library. To find the beginning, i'd use the address returned by _dyld_get_image_header - Is that correct?
Last question: I wanted to load a dynamic lib system-wide so i assumed i could use DYLD_INSERT_LIBRARIES to do just that. However, every binary i try to execute after inserting my lib crashes and produces a bus error! Did i forget something or is it the dynamic library that causes the crash?
the libraries are located at :
/System/Library/Caches/com.apple.dyld/dyld_shared_cache_armv6 (_armv7)
This is a big file were all the single libraries have been joined into one large one.
See http://iphonedevwiki.net/index.php/MobileSubstrate for hooking on jailbroken device
Yes one can determine the position of a dylib in memory, even on non jailbroken devices.
parse the LC_SEGMENT(_TEXT)-Section Header(_text) of the library then you can get the base address of the library and the size of the TEXT __text segment. Then query for the vmslide. Add this to the base address of the TEXT __text.
A detailed description of the mach-o file format can be found here:
https://developer.apple.com/library/mac/#documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html. Pay special attention to "segment_command"-structure.