How use Instruments and display the console in Command Lines applications

Question

I‘m using Xcode on OSX to develop command line C applications. I would also like to use Instruments to profile and find memory leaks.

However, I couldn‘t find a way to display the console when launching the application from within Instruments. I‘m also unable to attach to a running command line process (it exits with an error):

Here‘s an example code:

#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <setjmp.h>

static sigjmp_buf jmpbuf;

void handler(int sig) {
    char c[BUFSIZ];

    printf ("Got signal %d\n", sig);
    printf ("Deseja sair? (s/n) ");

    fgets(c, sizeof(c), stdin);

    if(c[0] == ‘s‘) {
    	exit(0);
    } else {
    	siglongjmp(jmpbuf, 1);
    }
}

int main(void) {
    char buf[BUFSIZ];

    signal(SIGINT, handler);

    sigsetjmp(jmpbuf, 1);

    while(1) {
    	printf(">>>");
    	fgets(buf, sizeof(buf), stdin);
    	printf ("Introduziu: %s\n", buf);
    }

    return(0);
}

Here‘s the error I got after launching Instruments, and trying to attach to the running process in xcode:

[Switching to process 1475]
[Switching to process 1475]
Error while running hook_stop:
sharedlibrary apply-load-rules all
Error while running hook_stop:
Invalid type combination in ordering comparison.
Error while running hook_stop:
Invalid type combination in ordering comparison.
Error while running hook_stop:
Error while running hook_stop:
Error while running hook_stop:
Error while running hook_stop:
Error while running hook_stop:
Error while running hook_stop:
Error while running hook_stop:

Unable to disassemble __CFInitialize.

Any thoughts?

score 3 · Accepted Answer

See this question for your answer.

From Brad Larson therein:

Run your application from within Xcode to have the console output piped there. While your application is running, start Instruments and choose an appropriate instrument. Under Default Target in the menu bar, select iPhone or Computer (whichever is appropriate for what you‘re testing), and under Attach to Process find the name of your executable.

When you click the record button, your application should start being profiled under Instruments while having its console output directed to Xcode. Unfortunately, this attachment process will need to come after the application has started, so you may have to profile the startup of your application separately.

Edit: If that didn‘t work, you may just need to restart your computer. Have you done that yet?

How use Instruments and display the console in Command Lines applications

3 Answers