C, GLib: Is there a method to get the size - can be applied to text file, binary file, folder, and symbolic link in common?

// gcc z.c -o z $(pkg-config --cflags --libs gtk+-2.0)
#include <string.h>
#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>
struct tst
{
    GtkWidget *win, *vb, *ent, *btn, *lbl;
    GtkAccelGroup *acc;
    GClosure *cls;
};
static void print_val(st开发者_开发技巧ruct tst *prg)
{
    const char *nam = gtk_entry_get_text(GTK_ENTRY(prg->ent));
    char *cont;
    g_file_get_contents(nam, &cont, NULL, NULL);
    int siz = strlen(cont);
    g_printf("%d\n", siz);
}
static void window_new()
{
    struct tst *prg = g_new0(struct tst, 1);
    prg->win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    prg->vb = gtk_vbox_new(TRUE, 0);
    prg->ent = gtk_entry_new();
    prg->btn = gtk_button_new_with_label("Print!");
    prg->lbl = gtk_label_new("Enter the string.");
    gtk_container_add(GTK_CONTAINER(prg->win), GTK_WIDGET(prg->vb));
    gtk_box_pack_start(GTK_BOX(prg->vb), GTK_WIDGET(prg->ent), FALSE, FALSE, 0);
    gtk_box_pack_start(GTK_BOX(prg->vb), GTK_WIDGET(prg->btn), FALSE, FALSE, 0);
    gtk_box_pack_start(GTK_BOX(prg->vb), GTK_WIDGET(prg->lbl), FALSE, FALSE, 0);
    g_signal_connect_swapped(prg->win, "destroy", G_CALLBACK(gtk_main_quit), NULL);
    g_signal_connect_swapped(prg->btn, "clicked", G_CALLBACK(print_val), prg);
    gtk_window_set_title(GTK_WINDOW(prg->win), "Enter the string");
    gtk_widget_show_all(GTK_WIDGET(prg->win));
}
int main(int argc, char *argv[])
{
    gtk_init(&argc, &argv);
    window_new();
    gtk_main();
    return 0;
}

With g_file_get_contents(), at least in this example program, I can get the size of text file, but I can't get the size of binary file, folder, and symbolic link.

When I try to get the size of binary file with that, it gives the weird value, not the size of binary file.

When I try to get the size of folder with that, it crashes with segmentation fault.

And when I try to get the size of symbolic link with that, it gives the size of regular file which link refers, not link itself.

Is there a method to get the size - can be applied to text file, binary file, folder, and symbolic link in common?

---

The usual way is

#include <sys/stat.h>

struct stat st;
if (lstat(filepath, &st) == -1) {
  perror(filepath);
  exit(1);
}
filesize = st.st_size;

Note that with lstat() the size reported will be the size of the symlink itself, not the object it references; if you didn't actually want the symlink's own size, use stat() instead.

---

You might have to use realpath() to resolve the symbolic links. After that you could just use fstat().

struct stat *s;
int fd;

s = malloc(sizeof(struct stat));

fd = open("somefile", O_RDONLY);
fstat(fd, s);
printf("%d\n", s->st_size);