0x02 - writing a C program

bin 0x02 of LiveOverflow’s binexp series
he asks to write a simple C program and compile it.
i did. it’s literally a main() with argv.

#include <stdio.h>

int main(int argc, char *argv[]) {
    if(argc == 2) {
        printf("YO BUD %s :P \n", argv[1]);
    } else {
        fprintf(stderr, "Usage: %s <name>\n", argv[0]);
        return 1;
    }
    return 0;
}

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breaking it down (my way)

• argc → how many arguments (arg count)
• argv[] → actual args (arg values)
• argv[0] → the name of the binary itself
• argv[1] → the string we pass

super basic stuff, but you gotta get it into muscle memory.

---

compile + run

gcc main.c -o main
./main lav

YO BUD lav :P

no input?

./main

Usage: ./main <name>

---

tl;dr

• got back to C (yes i’ve written before in diploma but this hit diff)
• wrote a basic argc/argv CLI prog
• compiled with gcc, ran it, aliased it
• now i’m comfy with the structure again

---

_{till the next leak :p
~ lav}