Biên dịch để gỡ lỗi và khởi động GDB

gcc -g main.c -o main            # thong tin go loi co ban
gcc -g3 main.c -o main           # them ca macro, xem duoc #define trong gdb
gcc -g3 -O0 main.c -o main       # khuyen dung: khong toi uu gi ca
gcc -ggdb3 -O0 main.c -o main    # dinh dang rieng cua GDB, chi tiet hon

# 1. Binh thuong
gdb ./main

# 2. Co tham so dong lenh
gdb --args ./main tep.txt --dai-dong

# Hoac dat sau khi vao gdb:
(gdb) set args tep.txt --dai-dong
(gdb) show args

# 3. Gan vao tien trinh dang chay
gdb -p 12345
gdb ./main 12345

# 4. Phan tich core dump
gdb ./main core
gdb ./main /var/lib/systemd/coredump/core.main.1000.xxx

# 5. Go loi tu xa, dung cho he nhung
gdbserver :1234 ./main          # tren may dich
gdb ./main                      # tren may cua ban
(gdb) target remote 192.168.1.5:1234

gdb -tui ./main                  # bat ngay tu dau

# Hoac trong gdb:
(gdb) layout src                 # cua so ma nguon
(gdb) layout asm                 # cua so hop ngu
(gdb) layout split               # ca hai
(gdb) layout regs                # them cua so thanh ghi
(gdb) tui disable                # tat

# Phim tat khi dang o TUI:
#   Ctrl-x a      bat tat TUI
#   Ctrl-x 1      mot cua so
#   Ctrl-x 2      hai cua so
#   Ctrl-l        ve lai man hinh khi bi loan
#   Ctrl-p, Ctrl-n   lich su lenh, vi mui ten dieu khien cuon ma nguon

# Dat o ~/.gdbinit de ap dung cho moi phien

set print pretty on            # in struct xuong dong, de doc
set print array on             # in mang xuong dong
set print array-indexes on     # kem chi so: [0] = 5, [1] = 3
set pagination off             # khong dung lai hoi "Press enter"
set history save on            # nho lenh giua cac phien
set history size 10000
set confirm off                # khong hoi lai khi quit hay delete

# Bai 35.6 se noi ky ve tep nay, ke ca lenh tu dinh nghia.

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

typedef struct Nut {
    int         ma;
    char        ten[16];
    struct Nut *sau;
} Nut;

static Nut *them(Nut *dau, int ma, const char *ten) {
    Nut *n = malloc(sizeof *n);

    n->ma = ma;
    strncpy(n->ten, ten, sizeof n->ten - 1);
    n->ten[sizeof n->ten - 1] = '\0';
    n->sau = dau;

    return n;
}

static int tong(const Nut *dau) {
    int t = 0;

    for (const Nut *p = dau; p != NULL; p = p->sau)
        t += p->ma;

    return t;
}

int main(void) {
    Nut *dau = NULL;

    dau = them(dau, 10, "mot");
    dau = them(dau, 20, "hai");
    dau = them(dau, 30, "ba");

    int a[5] = { 5, 3, 9, 1, 7 };
    int t = tong(dau);

    printf("tong = %d\n", t);
    printf("a[2] = %d\n", a[2]);

    return 0;
}