Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
605 views
in Technique[技术] by (71.8m points)

compiler construction - Avoiding the main (entry point) in a C program

Is it possible to avoid the entry point (main) in a C program. In the below code, is it possible to invoke the func() call without calling via main() in the below program ? If Yes, how to do it and when would it be required and why is such a provision given ?

int func(void)
{
     printf("This is func 
");
     return 0;
}

int main(void)
{
     printf("This is main 
");
     return 0;
}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

If you're using gcc, I found a thread that said you can use the -e command-line parameter to specify a different entry point; so you could use func as your entry point, which would leave main unused.

Note that this doesn't actually let you call another routine instead of main. Instead, it lets you call another routine instead of _start, which is the libc startup routine -- it does some setup and then it calls main. So if you do this, you'll lose some of the initialization code that's built into your runtime library, which might include things like parsing command-line arguments. Read up on this parameter before using it.

If you're using another compiler, there may or may not be a parameter for this.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...