How can I draw arrow like directory tree format in tikz?

Question

I want to draw following figure, I was not able to manage drawing its arrow format where like a tree-like format:

Reference: The Linux Programming Interface, Figure 41-1

---

My beginner approach:

\documentclass[tikz, border=1cm]{standalone}
\usetikzlibrary{shapes}
\begin{document}
\begin{tikzpicture}
    [ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        arrow/.style={->, >=stealth, semithick},
    ] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    \draw[help lines] (0,0) grid (8,4);
    [
    >=latex,shorten >=2pt,shorten <=2pt,shape aspect=1,
    % arrow/.style={->, >=stealth, very thick},
    % arrow/.style={<->, >=stealth, semithick},
    block/.style={}
    every node/.style = {font=\footnotesize}
    ]
    \node[
        rectangle,
        double=black,
        double distance =0.5pt,
        shape border rotate=90,
        draw,
        fill=white,
        shape aspect=0.2,
        font={\scriptsize\baselineskip=8pt},
        inner xsep=3pt,
        align=left,
    ]  (A) at (1,4) {\scriptsize \$ gcc -g -c \\ \,\, -fPIC - Wall \\ \,\, mod1.c mod2.c mod3.c};

    \node[circle,
        shape border rotate=90,
        inner xsep=0pt,
        draw] (B) at (-0.9,4.3) {\tiny 1};

    \node[
        rectangle,
        double=black,
        double distance =0.5pt,
        shape border rotate=90,
        draw,
        fill=white,
        font={\scriptsize\baselineskip=8pt},
        inner xsep=3pt,
        align=left,
    ]  (B) at (2,2) {mod1.o code};

    \node[
        rectangle,
        double=black,
        double distance =0.5pt,
        shape border rotate=90,
        draw,
        fill=white,
        font={\scriptsize\baselineskip=8pt},
        inner xsep=3pt,
        align=left,
    ]  (C) at (2,1) {mod2.o code};


    \node[
        rectangle,
        double=black,
        double distance =0.5pt,
        shape border rotate=90,
        draw,
        fill=white,
        font={\scriptsize\baselineskip=8pt},
        inner xsep=3pt,
        align=left,
    ]  (D) at (2,0) {mod3.o code};

    \draw [arrow] (A.south) -- (B.west);
    \draw [arrow] (A.south) -- (C.west);
    \draw [arrow] (A.south) -- (D.west);

\end{tikzpicture}
\end{document}

Here I was unable to manage to draw tree-format arrows as:

[*]
 │   
 ├──> [...]
 ├──> [...]
 └──> [...]

Answer 1

Like this:

In MWE below nodes are positioned relatively to each other. Also are defined styles for nodes and by this made picture code significantly shorter. For arrow are used orthogonal coordinates |- (for details of its use see TikZ & PGF manual, section 13.3.1 Intersections of Perpendicular Lines) as suggested in @ MS-SPO comment:

\documentclass[border=3.141592]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                 positioning}

\begin{document}
    \begin{tikzpicture}[
node distance = 4mm and 8mm,
   arr/.style = {-Stealth, semithick},
     C/.style = {circle, draw, font=\footnotesize},
     N/.style = {draw, very thick,
                 font=\small, align=left,
                 inner sep=5pt}
                        ]
\draw[help lines] (0,0) grid (8,5);
%
\node (n1) [N] at (3,4) {\$ gcc -g -c \\ 
                         \hphantom{\$ } -fPIC - Wall \\
                         \hphantom{\$ } mod1.c mod2.c mod3.c};
    \node[C, below left = 0 and 2mm of n1.north west] {1};
\node (n2) [N, below right=of n1.south]     {mod1.o code};
\node (n3) [N, below=of n2]     {mod2.o code};
\node (n4) [N, below=of n3]     {mod3.o code};
%
\draw[arr] (n1) |- (n2);
\draw[arr] (n1 |- n2) |- (n3);
\draw[arr] (n1 |- n3) |- (n4);
    \end{tikzpicture}
\end{document}

Addendum: Regarding your comment, you only need to change style of C nodes (to some extend only). For example:

...
    \begin{tikzpicture}[
node distance = 4mm and 8mm,
   arr/.style = {-Stealth, semithick},
     C/.style = {circle, draw, inner sep=1pt}, % <--- text in node will be \normalsize
     N/.style = {draw, very thick,
                 font=\small, align=left,
                 inner sep=5pt}
                        ]
...

gives

At bigger font in circle will enlarge circle too.