1 files changed, 71 insertions, 0 deletions
diff --git a/tests/checksummer.c b/tests/checksummer.c
new file mode 100644
index 00000000..c3eb1eea
--- /dev/null
+++ b/tests/checksummer.c
@@ -0,0 +1,71 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+const int MOD_ADLER = 65521;
+ 
+uint64_t adler32(unsigned char *data, int32_t len) /* where data is the location of the data in physical memory and 
+                                                       len is the length of the data in bytes */
+{
+    uint64_t a = 1, b = 0;
+    int32_t index;
+ 
+    /* Process each byte of the data in order */
+    for (index = 0; index < len; ++index)
+    {
+        a = (a + data[index]) % MOD_ADLER;
+        b = (b + a) % MOD_ADLER;
+    }
+ 
+    return (b << 16) | a;
+}
+
+int main(int argc, char* argv[]) {
+    long bufsize;
+
+    if (argc != 2) {
+	fputs("Need 1 argument\n", stderr);
+	return (EXIT_FAILURE);
+    }
+
+    unsigned char *source = NULL;
+    FILE *fp = fopen(argv[1], "rb");
+    if (fp != NULL) {
+        /* Go to the end of the file. */
+        if (fseek(fp, 0L, SEEK_END) == 0) {
+            /* Get the size of the file. */
+            bufsize = ftell(fp);
+            if (bufsize == -1) { fputs("Couldn't get size\n", stderr); return (EXIT_FAILURE); }
+    
+            /* Allocate our buffer to that size. */
+            source = malloc(sizeof(char) * (bufsize + 1));
+            if (source == NULL) { fputs("Couldn't allocate\n", stderr); return (EXIT_FAILURE); }
+    
+            /* Go back to the start of the file. */
+            if (fseek(fp, 0L, SEEK_SET) == -1) { fputs("Couldn't seek\n", stderr); return (EXIT_FAILURE); }
+    
+            /* Read the entire file into memory. */
+            size_t newLen = fread(source, sizeof(char), bufsize, fp);
+            if (newLen == 0) {
+                fputs("Error reading file\n", stderr);
+                //return (EXIT_FAILURE);
+            } else {
+                source[++newLen] = '\0'; /* Just to be safe. */
+            }
+        } else {
+          fputs("Couldn't seek to end\n", stderr);
+          return (EXIT_FAILURE);
+        }
+        fclose(fp);
+    } else {
+      fputs("Couldn't open\n", stderr);
+      return (EXIT_FAILURE);
+    }
+
+    printf("%d\n", (uint32_t) adler32(source, bufsize));
+    
+    free(source); /* Don't forget to call free() later! */
+
+    return (EXIT_SUCCESS);
+
+}