From 7e059e45e317f8d779488e6385ce0ca2a00751d5 Mon Sep 17 00:00:00 2001
From: Dan Buch <daniel.buch@gmail.com>
Date: Thu, 14 Apr 2016 23:48:19 -0400
Subject: [PATCH] ex20 with dbg.h

---
 lcthw-remnants-2/dbg.h  |  30 ++++++++++
 lcthw-remnants-2/ex20.c | 118 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 148 insertions(+)
 create mode 100644 lcthw-remnants-2/dbg.h
 create mode 100644 lcthw-remnants-2/ex20.c

diff --git a/lcthw-remnants-2/dbg.h b/lcthw-remnants-2/dbg.h
new file mode 100644
index 0000000..21aacac
--- /dev/null
+++ b/lcthw-remnants-2/dbg.h
@@ -0,0 +1,30 @@
+#ifndef __dbg_h__
+#define __dbg_h__
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#ifdef NDEBUG
+#define debug(M, ...)
+#else
+#define debug(M, ...) fprintf(stderr, "DEBUG %s:%d: " M "\n", __FILE__, __LINE__, ##__VA_ARGS__)
+#endif
+
+#define clean_errno() (errno == 0 ? "None" : strerror(errno))
+
+#define log_err(M, ...) fprintf(stderr, "[ERROR] (%s:%d: errno: %s) " M "\n", __FILE__, __LINE__, clean_errno(), ##__VA_ARGS__)
+
+#define log_warn(M, ...) fprintf(stderr, "[WARN] (%s:%d: errno: %s) " M "\n", __FILE__, __LINE__, clean_errno(), ##__VA_ARGS__)
+
+#define log_info(M, ...) fprintf(stderr, "[INFO] (%s:%d) " M "\n", __FILE__, __LINE__, ##__VA_ARGS__)
+
+#define check(A, M, ...) if(!(A)) { log_err(M, ##__VA_ARGS__); errno=0; goto error; }
+
+#define sentinel(M, ...) { log_err(M, ##__VA_ARGS__); errno=0; goto error; }
+
+#define check_mem(A) check((A), "Out of memory.")
+
+#define check_debug(A, M, ...) if(!(A)) { debug(M, ##__VA_ARGS__); errno=0; goto error; }
+
+#endif
diff --git a/lcthw-remnants-2/ex20.c b/lcthw-remnants-2/ex20.c
new file mode 100644
index 0000000..853da90
--- /dev/null
+++ b/lcthw-remnants-2/ex20.c
@@ -0,0 +1,118 @@
+#include "dbg.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+
+void test_debug()
+{
+  // notice you don't need the \n
+  debug("I have Brown Hair.");
+
+  // passing in arguments like printf
+  debug("I am %d years old.", 37);
+}
+
+void test_log_err()
+{
+  log_err("I believe everything is broken.");
+  log_err("There are %d problems in %s.", 0, "space");
+}
+
+void test_log_warn()
+{
+  log_warn("You can safely ignore this.");
+  log_warn("Maybe consider looking at: %s.", "/etc/passwd");
+}
+
+void test_log_info()
+{
+  log_info("Well I did something mundane.");
+  log_info("It happened %f times today.", 1.3f);
+}
+
+int test_check(char *file_name)
+{
+  FILE *input = NULL;
+  char *block = NULL;
+
+  block = malloc(100);
+  check_mem(block); // should work
+
+  input = fopen(file_name, "r");
+  check(input, "Failed to open %s.", file_name);
+
+  free(block);
+  fclose(input);
+  return 0;
+
+error:
+  if(block) free(block);
+  if(input) fclose(input);
+  return -1;
+}
+
+int test_sentinel(int code)
+{
+  char *temp = malloc(100);
+  check_mem(temp);
+
+  switch(code) {
+    case 1:
+      log_info("It worked.");
+      break;
+    default:
+      sentinel("I shouldn't run.");
+  }
+
+  free(temp);
+  return 0;
+
+error:
+  if(temp) free(temp);
+  return -1;
+}
+
+int test_check_mem()
+{
+  char *test = NULL;
+  check_mem(test);
+
+  free(test);
+  return 1;
+
+error:
+  return -1;
+}
+
+int test_check_debug()
+{
+  int i = 0;
+  check_debug(i != 0, "Oops, I was 0.");
+
+  return 0;
+error:
+  return -1;
+}
+
+int main(int argc, char *argv[])
+{
+  check(argc == 2, "Need an argument.");
+
+  test_debug();
+  test_log_err();
+  test_log_warn();
+  test_log_info();
+
+  check(test_check("ex20.c") == 0, "failed with ex20.c");
+  check(test_check(argv[1]) == -1, "failed with argv");
+  check(test_sentinel(1) == 0, "test_sentinel failed.");
+  check(test_sentinel(100) == -1,  "test_sentinel failed.");
+  check(test_check_mem() == -1, "test_check_mem failed.");
+  check(test_check_debug() == -1, "test_check_debug failed.");
+
+  return 0;
+
+error:
+  return 1;
+}
+