Ubuntu:: ./program: 权限被拒绝

Question

Firstly, my problem is similar to this: Ubuntu says "bash: ./program Permission denied"

However, I feel the need to further clarify.

When I compile my program using:

gcc -c file.c -o file

and run

./file 

I get this error:

bash:./file: Permission denied

When I use

chmod u+x file 

and then run

./file

I get this error:

bash: ./file: cannot execute binary file: Exec format error

However, when I compile using

gcc file.c -o file <br/>

My program runs perfectly well using

./file

Can someone point out what is the problem with using the -c argument with gcc ?

Answer 1

Type gcc --help to see some help.

-c                      Only run preprocess, compile, and assemble steps

This means that, when run with this option, GCC doesn't link the executable with any (even system) libraries.

In short, to run a program, the OS needs a starting point, which is located in some system library. Since in your case GCC isn't linking the executable with anything , the OS doesn't know how to run the file , where to start.