CODEWITHSUNDEEP
c
user506710
user506710

Reputation:

Debugging in c for log file

I have written down a program in c and I am trying to create a log file of it.

The problem I am facing is that while printing the outputs of each line in the file I want to write some distinctive feature such as the time of execution of that line or even the line number in the code.

Is there any way I can get to know any of these two.

I don't mind if you suggest some other way to get a distinctive feature. All I want is that looking at the log file the user gets to know that a certain part of the code was getting executed.

Thanks

I am working on linux and thus using the GCC compiler....

I have made a header file and in it I am for testing purposes writing __LINE__ . What I want to do is that in a program when I include this function of header file the line number gets printed where the function is. But instead i get the line number of the header file printf statement.

What do I need to do to get the line number of the file . This is just a test format given below :-

new.h 
       void print()
       {
           printf("Line number is %d",__LINE__);
       }

actual file
       #include "new.h"
       int main()
       {
            print();
       }

Then I want that the line number that should be printed is that of actual file and not new.h which happens now....

Upvotes: 0

Views: 1433

Answers (5)

Lou Franco
Lou Franco

Reputation: 89142

Use __FILE__ and __LINE__ to get the current file and line number.

Edit: based on your edited question. Here's a simple way to do it to start.

new.h 

#define PRINT() print(__LINE__)

void print(int line)
{
    printf("Line number is %d",line);
}

actual file

   #include "new.h"
   int main()
   {
        PRINT();
   }

Upvotes: 0

lijie
lijie

Reputation: 4871

The line number can be obtained by the preprocessor macro __LINE__. The file is __FILE__. As for time, use the relevant OS library.

Or, use a logging library that support these.

Upvotes: 0

Vladimir Lagunov
Vladimir Lagunov

Reputation: 1905

In GCC you can get line number as "__LINE__". Filename - "__FILE__".

If you want calculate execution time then just remember time on start, get time on end and substract them.

Upvotes: 0

Carl Norum
Carl Norum

Reputation: 224844

Most C compilers provide some macros to identify each line, function, etc. With GCC, for example, you can use __LINE__, __FUNCTION__, and so on. Check your compiler documentation for details. To get a timestamp, you'll need to let us know what system you're working on.

Upvotes: 2

Bojangles
Bojangles

Reputation: 101473

If you want the actual date and time the function was executed, try asctime(). There is a good reference on how it's done here.

This will output something akin to Sat May 20 17:36:17 2000. If you want the time in seconds since the program started, have a variable such as int startTime = time() which holds the program start time in seconds from the Unix Epoch. Then, simply print startTime - time() to get the number of seconds since program start.

Upvotes: 2

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