diff --git a/A0/.gitignore b/A0/.gitignore
new file mode 100644
index 0000000..ede6568
--- /dev/null
+++ b/A0/.gitignore
@@ -0,0 +1,2 @@
+file.dsym/
+test_files/
\ No newline at end of file
diff --git a/A0/Makefile b/A0/Makefile
new file mode 100644
index 0000000..32024df
--- /dev/null
+++ b/A0/Makefile
@@ -0,0 +1,14 @@
+CC=gcc
+CFLAGS=-std=c11 -Wall -Werror -Wextra -pedantic -g3
+
+file: file.c Makefile
+	$(CC) $(CFLAGS) -o file file.c
+
+../src.zip: file.c Makefile test.sh
+	cd .. && zip src.zip src/file.c src/Makefile src/test.sh
+
+clean:
+	rm -f *.o
+	rm -f file
+
+.PHONY: clean
diff --git a/A0/file b/A0/file
new file mode 100755
index 0000000..553c19c
Binary files /dev/null and b/A0/file differ
diff --git a/A0/file.c b/A0/file.c
index e69de29..9d9d7cc 100644
--- a/A0/file.c
+++ b/A0/file.c
@@ -0,0 +1,132 @@
+#include <stdio.h>  // fprintf, stdout, stderr.
+#include <stdlib.h> // exit, EXIT_FAILURE, EXIT_SUCCESS.
+#include <string.h> // strerror.
+#include <errno.h>  // errno.
+#include <stdbool.h>
+
+enum FileType{ASCII, ISO, UTF, data};
+
+bool is_utf8(FILE* f) {
+    rewind(f);
+    char byte;
+    bool utf8_byte;
+    int char_length;
+    for (;;) {
+        if (fread(&byte, 1, 1, f) == 0) {
+            break;
+        }
+        utf8_byte = true;
+        for (int j = 0 ; 1 ; j++) {
+            if (byte >> 7 == 0) {
+                char_length = max(j, 1);
+                break;
+            }
+            byte = byte << 1;
+        }
+        for (int i = 1 ; i < char_length ; i++) {
+            printf("esnathusrcaho");
+        }
+    }
+    return true;
+}
+
+bool is_iso8859(FILE* f) {
+    rewind(f);
+    int iso8859_CHARACTERS[197];
+
+    for (int i = 0 ; i < 7 ; i++) {
+        iso8859_CHARACTERS[i] = i+7;
+    }
+        iso8859_CHARACTERS[7] = 27;
+    for (int i = 0 ; i < 94 ; i++) {
+        iso8859_CHARACTERS[i+8] = i+32;
+    }
+
+    for (int i = 0 ; i < 95 ; i++) {
+        iso8859_CHARACTERS[i+102] = i+160;
+    }
+    char byte;
+    bool is_iso8859;
+    for (;;) {
+        if (fread(&byte, 1, 1, f) == 0) {
+            break;
+        }
+        is_iso8859 = false;
+        for (int i = 0 ; i < 95 ; i++) {
+            if (byte == iso8859_CHARACTERS[i]) {
+                is_iso8859 = true;
+                break;
+            }
+        }
+        if (! is_iso8859) {
+            return false;
+        }
+    
+    }
+    return true;
+}
+
+bool is_ascii(FILE* f) {
+    rewind(f);
+    int ASCII_CHARACTERS[102];
+
+    for (int i = 0 ; i < 7 ; i++) {
+        ASCII_CHARACTERS[i] = i+7;
+    }
+    ASCII_CHARACTERS[7] = 27;
+    for (int i = 0 ; i < 94 ; i++) {
+        ASCII_CHARACTERS[i+8] = i+32;
+    }
+
+    char byte;
+    bool ascii_byte;
+    for (;;) {
+        if (fread(&byte, 1, 1, f) == 0) {
+            break;
+        }
+        ascii_byte = false;
+        for (int i = 0 ; i < 102 ; i++) {
+            if (byte == ASCII_CHARACTERS[i]) {
+                ascii_byte = true;
+                break;
+            }
+        }
+        if (! ascii_byte) {
+            return false;
+        }
+    
+    }
+    return true;
+    
+}
+
+int print_error(char* path, int errnum) {
+    return fprintf(stderr, "%s: cannot determine (%s)\n", path, strerror(errnum));
+}
+
+int main(int argc, char* argv[]) {
+
+    if (argc != 2) {
+        printf("Wrong number of arguments!\n");
+        return EXIT_FAILURE;
+    }
+
+    FILE* f = fopen(argv[1], "r");
+    
+    if (f == NULL) {
+        print_error(argv[2], errno);
+    }
+    char byte;
+    if (fread(&byte, sizeof(char), 1, f) == 0) {
+        fprintf(stdout, "%s: empty\n", argv[1]);
+    } else if (is_ascii(f)) {
+        fprintf(stdout, "%s: ASCII text\n", argv[1]);
+    } else if (is_iso8859(f)) {
+        fprintf(stdout, "%s: ISO-8859 text\n", argv[1]);
+    } else {
+        fprintf(stdout, "%s: data\n", argv[1]);
+    }    
+
+    fclose(f);
+    return EXIT_SUCCESS;
+}
diff --git a/A0/test.sh b/A0/test.sh
new file mode 100755
index 0000000..af8bd1f
--- /dev/null
+++ b/A0/test.sh
@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+
+# Exit immediately if any command below fails.
+set -e
+
+make
+
+
+echo "Generating a test_files directory.."
+mkdir -p test_files
+rm -f test_files/*
+
+
+echo "Generating test files.."
+printf "Hello, World!\n" > test_files/ascii.input
+printf "Hello, World!" > test_files/ascii2.input
+printf "Hello,\x00World!\n" > test_files/data.input
+printf "Hællo,\x00World!\n" > test_files/iso1.input
+printf "Hello,\x00Wørld!\n" > test_files/iso2.input
+printf "Hello,\x00World!\n" > test_files/utf81.input
+printf "Hello,\x00World!\n" > test_files/utf82.input
+printf "" > test_files/empty.input
+### TODO: Generate more test files ###
+
+
+echo "Running the tests.."
+exitcode=0
+for f in test_files/*.input
+do
+  echo ">>> Testing ${f}.."
+  file    "${f}" | sed 's/ASCII text.*/ASCII text/' > "${f}.expected"
+  ./file  "${f}" > "${f}.actual"
+
+  if ! diff -u "${f}.expected" "${f}.actual"
+  then
+    echo ">>> Failed :-("
+    exitcode=1
+  else
+    echo ">>> Success :-)"
+  fi
+done
+exit $exitcodeASCII