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@nclv
Created August 31, 2020 07:51
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From `Learn C the Hard Way`
#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
#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;
}
@nclv
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nclv commented Aug 31, 2020

cc -Wall -g -DNDEBUG test_debug.c -o test_debug

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