stat() does not work for .so files

Question

I am facing an issue with stat() . stat() does not seem to be working with .so files. It gives the error

No such file or directory .

Why is this happening?

As requested I paste a portion of the code:

int main()
 {
    char str[300];
    struct stat str_buf;
    strcpy(str,"path/to/my/library/libfuncs.so");

    if(stat(str,$str_buf)==-1)
       perror("stat");
     ....
  }

Thus the error comes as stat No such file or directory

But the same code works fine for other files and directories. libfuncs.so is my generated shared library.

@Chung: Don't use '$' for names, it is not part of the C standard. Also, whenever you sense a bug in an established library, and glibc _is_ an established library, assume that _you_ did something wrong. — Sebastian Mach, Jul 15 '11 at 12:50

unwind · Accepted Answer · 2011-07-15T12:45:18.127

1

Many ".so" files are in fact symbolic links due to versioning issues. You might want to use lstat() in those cases, to stat the actual link.

The error you're getting ("No such file or directory") seems to imply that the symbolic link is pointing at something that doesn't exist. In these cases stat:ing the link itself helps, but of course that might not be what you want to do. Check the link's target. If the path in the link is relative, perhaps you're executing the code from a different directory?

edited Jul 15 '11 at 12:45

answered Jul 15 '11 at 12:36

unwind

391,730
64
469
606

`stat` works for symlinks too. `lstat` dereferences the link. – cnicutar Jul 15 '11 at 12:38
@cnicutar: Of course, but it might fail if the target file doesn't exist. This might be what the OP is experiencing. – unwind Jul 15 '11 at 12:43
Oh, I get it :-). Mistake above: ~~dereferences~~ doesn't. – cnicutar Jul 15 '11 at 12:46
@cnicular...I beleive you are correct. So what may be the reason – Chung Jul 15 '11 at 12:50
@Chung: So you really have your `libfuncs.so` located at `path/to/my/library/libfuncs.so`? I hope so, because otherwise you have not shown us an actual portion of your code, as claimed. – Sebastian Mach Jul 15 '11 at 14:10

Sebastian Mach · Answer 2 · 2011-07-15T13:03:15.863

Probable reason

I can only guess that "path/to/my/library/libfuncs.so" does not really exist. You could test that simply by typing ls "path/to/my/library/libfuncs.so".

I am pretty sure that

stat() does ~~not~~ work

I guess this once again solves for a "bug" in a very well established library.

Theoratically possible reason.

You use $ for a variable name. That is not permitted. The C99 Standard has this to say about this:

Both the basic source and basic execution character sets shall have the following members: the 26 uppercase letters of the Latin alphabet
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

the 26 lowercase letters of the Latin alphabet
a b c d e f g h i j k l m n o p q r s t u v w x y z

the 10 decimal digits
0 1 2 3 4 5 6 7 8 9

the following 29 graphic characters
! " # % & ' ( ) * + , - . / : ; < = > ? [ \ ] ^ _ { | } ~

Further:

If ...

any other characters are encountered in a source file (except in an identifier, a character constant, a string literal, a header name, a comment, or a preprocessing token that is never converted to a token),

guess what? ** drumroll **

the behavior is undefined.

Yay party.^{but I think it is the first reason.}

stat() does not work for .so files

2 Answers2