From d33761b04e8d9cd351bdfd4b523167c03f7033c2 Mon Sep 17 00:00:00 2001
From: Alex Gustafsson <alexg@axis.com>
Date: Wed, 24 Nov 2021 15:28:40 +0100
Subject: [PATCH] Add basic c support

---
 2020/1/main.c   | 15 +++++++++++++++
 scripts/run.sh  |  5 +++++
 utils/c/input.c | 34 ++++++++++++++++++++++++++++++++++
 utils/c/input.h | 12 ++++++++++++
 4 files changed, 66 insertions(+)
 create mode 100644 2020/1/main.c
 create mode 100644 utils/c/input.c
 create mode 100644 utils/c/input.h

diff --git a/2020/1/main.c b/2020/1/main.c
new file mode 100644
index 0000000..d4fb51d
--- /dev/null
+++ b/2020/1/main.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../../utils/c/input.h"
+
+int main(int argc, char **argv) {
+  input_t input = read_input();
+  if (input == NULL) {
+    return EXIT_FAILURE;
+  }
+
+  printf("%s\n", input);
+  free(input);
+  return EXIT_SUCCESS;
+}
diff --git a/scripts/run.sh b/scripts/run.sh
index 8dce5ac..4f74a7d 100755
--- a/scripts/run.sh
+++ b/scripts/run.sh
@@ -22,6 +22,7 @@ fi
 main_files="$(find "$year/$day" -depth 1 -iname "main*")"
 for file in $main_files; do
   name="$(basename "$file")"
+  directory="$(dirname "$file")"
   case "${name##*.}" in
     "go")
       go run "$file"
@@ -33,6 +34,10 @@ for file in $main_files; do
       export PYTHONPATH="$PWD/utils/python/:$PYTHONPATH"
       python3 "$file"
       ;;
+    "c")
+      out="$(mktemp --suffix=.main)"
+      gcc -o "$out" "$directory/"*.c utils/c/*.c && "$out"
+      ;;
     *)
       echo "unsupported $file"
   esac
diff --git a/utils/c/input.c b/utils/c/input.c
new file mode 100644
index 0000000..358cca0
--- /dev/null
+++ b/utils/c/input.c
@@ -0,0 +1,34 @@
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "input.h"
+
+input_t read_input_impl(char *main_file) {
+  char *directory = dirname(main_file);
+
+  size_t directory_length = strlen(directory);
+
+  // Room for the directory, a slash, input.txt and a null byte
+  size_t path_length = path_length + 1 + 9 + 1;
+  char *input_path = (char *)malloc(path_length);
+  if (input_path == NULL) {
+    return NULL;
+  }
+  strncpy(input_path, directory, path_length);
+  strncpy(input_path + directory_length, "/input.txt", path_length);
+  input_path[path_length - 1] = 0;
+
+  FILE *file = fopen(input_path, "r");
+  fseek(file, 0, SEEK_END);
+  size_t file_size = ftell(file);
+  fseek(file, 0, SEEK_SET);
+
+  char *input = malloc(file_size + 1);
+  fread(input, sizeof(char), file_size, file);
+  fclose(file);
+  input[file_size] = 0;
+
+  return (input_t)input;
+}
diff --git a/utils/c/input.h b/utils/c/input.h
new file mode 100644
index 0000000..978324b
--- /dev/null
+++ b/utils/c/input.h
@@ -0,0 +1,12 @@
+#ifndef __INPUT_H__
+#define __INPUT_H__
+
+#include <stdlib.h>
+
+typedef char* input_t;
+
+#define read_input() read_input_impl(__FILE__)
+
+input_t read_input_impl(char *main_file);
+
+#endif