Filesize

filesize.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+/* Different ways to get filesizes, some are linux-specific (i think), some are posix */
+
+void file_tell(void);
+void file_stat(void);
+void file_end(void);
+
+int main(void) {
+    file_stat();
+    file_tell();
+    file_end();
+
+    return EXIT_SUCCESS;
+}
+
+/* This works on linux, but may not be posix compliant */
+void file_stat(void) {
+    const char *filename = "filesize.c";
+    struct stat st;
+
+    if (stat(filename, &st) == 0) {
+        printf("File size: %lld bytes\n", (long long)st.st_size);
+    } else {
+        perror("stat");
+    }
+}
+
+/* This works on all posix systems afaik */
+void file_tell(void) {
+    FILE *f = fopen("filesize.c", "rb");
+    if (!f) {
+        perror("fopen");
+        return;
+    }
+
+    fseek(f, 0, SEEK_END);
+    long size = ftell(f);
+    fclose(f);
+
+    if (size >= 0) {
+        printf("File size: %ld bytes\n", size);
+    } else {
+        perror("ftell");
+    }
+}
+
+/* This is bad for obvious reasons*/
+void file_end(void) {
+    FILE *f = fopen("filesize.c", "rb");
+    if (!f)
+        return;
+
+    size_t size = 0;
+    while (fgetc(f) != EOF) {
+        size++;
+    }
+    fclose(f);
+
+    printf("File size: %zu bytes\n", size);
+}