Thread: implicit declaration of function ‘get_current_dir_name’ ad is not corrected

I had a big problem and I do not know how to solve it.
I wrote at the beginning of the file:

Code:

#define __USE_GNU
#include <unistd.h>

In the file unistd.h I have here this line:

Code:

#ifdef	__USE_GNU
/* Return a malloc'd string containing the current directory name.
   If the environment variable `PWD' is set, and its value is correct,
   that value is used.  */
extern char *get_current_dir_name (void) __THROW;
#endif

In the file I have this code:

Code:

char *DName;
                 DName = get_current_dir_name();

But at compilation I see here such warning:

Code:

ls.c: In function ‘printLine’:
ls.c:268:18: warning: implicit declaration of function ‘get_current_dir_name’ [-Wimplicit-function-declaration]
                  DName = get_current_dir_name();
                  ^
ls.c:268:24: warning: assignment makes pointer from integer without a cast
                  DName = get_current_dir_name();
                        ^

How are you compiling your program? The get_current_dir_name() function is a compiler specific function that may not be available with certain compile flags.



Jim

Originally Posted by jimblumberg

How are you compiling your program? The get_current_dir_name() function is a compiler specific function that may not be available with certain compile flags.



Jim

Like this:

Code:

gcc -D_XOPEN_SOURCE=500 -std=c99 sds.o ls.c -o ls

Using the "-std=c99" flag may disable the use of that function.

What operating system are you using?

Jim

Read the man page.
You need to define _GNU_SOURCE, not __USE_GNU (whatever that is).

Originally Posted by algorism

Read the man page.
You need to define _GNU_SOURCE, not __USE_GNU (whatever that is).

This define did not work for me, but now all of a sudden everything turned out. Problem solved