C语言 通过宏修改 printf()s 以包含文件和行号信息
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原文地址: http://stackoverflow.com/questions/15549893/
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Modify printf()s via macro to include file and line number information
提问by user138645
I was just wondering if there is some macro-hack we can use, to alter existing printf() statements in a project.
我只是想知道我们是否可以使用一些宏技巧来改变项目中现有的 printf() 语句。
/* file.c */
printf ("%s", strerror(errno));
/* After macro processing, this line would become */
printf ("%s %s %d", strerror(errno), __FILE__, __LINE__);
回答by Some programmer dude
With the caveat in my comment, you could do it using a variadic macro:
有了我评论中的警告，您可以使用可变参数宏来做到这一点：
#define PRINTF_FL(format, ...) \
printf(format " %s %d", __VA_ARGS__, __FILE__, __LINE__)
回答by kamituel
Try this:
尝试这个：
#define debug(fmt, ...) printf("%s:%d: " fmt, __FILE__, __LINE__, __VA_ARGS__);
I used name debuginstead of printf, because I don't think you should override standard functions. You could break something.
我使用 namedebug而不是printf，因为我认为您不应该覆盖标准函数。你可以打破一些东西。
Use this like:
像这样使用：
debug("This is debug no %d", 5);
To get output similar to:
要获得类似于以下内容的输出：
program.c:12: this is debug no 5
(file: program.c, line: 12).
（文件：program.c，行：12）。
回答by MOHAMED
to redefine the printfdo not use undefjust define the following printfmacro in your header file
重新定义printf不要使用，undef只需printf在头文件中定义以下宏
#define printf(MESSAGE,args...) { \
const char *A[] = {MESSAGE}; \
printf("%s %d",__FILE__,__LINE__); fflush(stdout);\
if(sizeof(A) > 0) {\
printf("::"); \
printf(*A,##args); \
} else {\
printf("\n"); \
}\
}
you can use your new printfmacro in your code in this way
您可以通过printf这种方式在代码中使用新宏
printf(); // it will print only the file name and the line number
or in this way
或以这种方式
printf("debug message any data %d\n", 5);
回答by Eddy_Em
And here is my "half penny".
这是我的“半分钱”。
Function name & debug messages:
函数名称和调试消息：
// debug mode, -DEBUG
#ifdef EBUG
#define FNAME() fprintf(stderr, "\n%s (%s, line %d)\n", __func__, __FILE__, __LINE__)
#define DBG(...) do{fprintf(stderr, "%s (%s, line %d): ", __func__, __FILE__, __LINE__); \
fprintf(stderr, __VA_ARGS__); \
fprintf(stderr, "\n");} while(0)
#else
#define FNAME() do{}while(0)
#define DBG(...) do{}while(0)
#endif //EBUG
Use macro FNAME()to show just name of function & file/line, DBG(text)to show printf-like debug message with info about function name & file/line.
使用宏FNAME()仅显示函数名称和文件/行，DBG(text)以显示类似 printf 的调试消息以及有关函数名称和文件/行的信息。
And something that may be useful for coloured debug & error/warning messages.
以及可能对彩色调试和错误/警告消息有用的东西。
In header file:
在头文件中：
extern int globErr;
#define ERR(...) do{globErr=errno; _WARN(__VA_ARGS__); exit(-1);}while(0)
#define WARN(...) do{globErr=errno; _WARN(__VA_ARGS__);}while(0)
#define WARNX(...) do{globErr=0; _WARN(__VA_ARGS__);}while(0)
// functions for color output in tty & no-color in pipes
EXTERN int (*red)(const char *fmt, ...);
EXTERN int (*_WARN)(const char *fmt, ...);
EXTERN int (*green)(const char *fmt, ...);
In C file:
在 C 文件中：
int globErr = 0; // errno for WARN/ERR
// pointers to coloured output printf
int (*red)(const char *fmt, ...);
int (*green)(const char *fmt, ...);
int (*_WARN)(const char *fmt, ...);
/*
* format red / green messages
* name: r_pr_, g_pr_
* @param fmt ... - printf-like format
* @return number of printed symbols
*/
int r_pr_(const char *fmt, ...){
va_list ar; int i;
printf(RED);
va_start(ar, fmt);
i = vprintf(fmt, ar);
va_end(ar);
printf(OLDCOLOR);
return i;
}
int g_pr_(const char *fmt, ...){
va_list ar; int i;
printf(GREEN);
va_start(ar, fmt);
i = vprintf(fmt, ar);
va_end(ar);
printf(OLDCOLOR);
return i;
}
/*
* print red error/warning messages (if output is a tty)
* @param fmt ... - printf-like format
* @return number of printed symbols
*/
int r_WARN(const char *fmt, ...){
va_list ar; int i = 1;
fprintf(stderr, RED);
va_start(ar, fmt);
if(globErr){
errno = globErr;
vwarn(fmt, ar);
errno = 0;
globErr = 0;
}else
i = vfprintf(stderr, fmt, ar);
va_end(ar);
i++;
fprintf(stderr, OLDCOLOR "\n");
return i;
}
const char stars[] = "****************************************";
/*
* notty variants of coloured printf
* name: s_WARN, r_pr_notty
* @param fmt ... - printf-like format
* @return number of printed symbols
*/
int s_WARN(const char *fmt, ...){
va_list ar; int i;
i = fprintf(stderr, "\n%s\n", stars);
va_start(ar, fmt);
if(globErr){
errno = globErr;
vwarn(fmt, ar);
errno = 0;
globErr = 0;
}else
i = +vfprintf(stderr, fmt, ar);
va_end(ar);
i += fprintf(stderr, "\n%s\n", stars);
i += fprintf(stderr, "\n");
return i;
}
int r_pr_notty(const char *fmt, ...){
va_list ar; int i;
i = printf("\n%s\n", stars);
va_start(ar, fmt);
i += vprintf(fmt, ar);
va_end(ar);
i += printf("\n%s\n", stars);
return i;
}
In main():
在 main() 中：
if(isatty(STDOUT_FILENO)){ // make color output in tty
red = r_pr_; green = g_pr_;
}else{ // no colors in case of pipe
red = r_pr_notty; green = printf;
}
if(isatty(STDERR_FILENO)) _WARN = r_WARN;
else _WARN = s_WARN;
After that you will be able to use coloured output in case running in terminal and non-coloured in case of pipe. Functions redand greenare analogues of printffor coloured output. Function _WARNused in macros to show user message and string for errno: ERRfor case of errors (ends with exit), WARN— analogue of ERRbut without exitand WARNXto show messages without errno.
之后，您将能够在终端中运行时使用彩色输出，而在管道中使用非彩色输出。功能red和green是printf彩色输出的类似物。_WARN在宏中用于显示用户消息和字符串的函数errno：ERR对于错误的情况（以 结尾exit），WARN— 类似于ERR但没有exit和WARNX显示没有 的消息errno。
回答by Shrikant Khanduri
Define below Macro MYPRINT. Include File name, Line number, Function name and \n
在下面定义宏 MYPRINT。包括文件名、行号、函数名和\n
#define MYPRINT(str,args...) printf("%s:%d %s() "str"\n",__FILE__,__LINE__,__func__, ##args)
