简单的 Hello World 示例中的分段错误？

Question

I'm just starting out with C and I've got this code block for beginners:

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

int main() {
    printf('     /\n');
    printf('    /\n');
    printf('   /\n');
    printf('  /\n');
    printf(' /\n');
    printf('/\n');
    return 0;
}

I'm using Code Blocks to build and run it. It prints out Segmentation Fault, core dumped . The editor is using default gcc compiler.

What's wrong with the code?

Answer 1

You use single quotes calling printf instead of double quotes. It's going to turn the first few characters into an integer, and cast that integer as a pointer and access wherever it points as a format string, which is most likely not yet mapped, so segmentation fault.

Use double quotes.

As Ed Heal mentioned, always compile with warnings enabled. C isn't like other languages. Warnings are usually very serious problems.

Answer 2

Use double quotes for strings:

int main() {
    printf("     /\n");
    printf("    /\n");
    printf("   /\n");
    printf("  /\n");
    printf(" /\n");
    printf("/\n");
    return 0;
}