Suppress warning: using `mktemp 'is dangerous

Question

How can I suppress the following warning from the gcc linker:

warning: using "mktemp" is dangerous, it is better to use "mkstemp"

I know it is better to use mkstemp() , but for some reason I have to use the mktemp() function.

Answer 1

I think you need a path because you pass it to a library that only accepts path names as an argument, not file descriptors or FILE pointers. If so, you can create a temporary directory with mkdtemp and put your file there, then the actual name does not matter, because the path is already unique due to the directory.

Answer 2

If you use to use mktemp , you can do nothing to stop this warning without deleting the section that mktemp uses from libc.so.6.

Why do you have to use mktemp ?

Answer 3

Two things:

• mktemp not a standard feature
• the warning is special, implemented in the linker as a section of .gnu.warning.mktemp

Use your own API if you really need to burn to disk. Or mkstemp() as suggested.

Answer 4

If you are statically linking the runtime, then another option is to write your own version of mktemp in the object file. The component should prefer your version over the run-time version.

Change Thanks to Jason Coco for pointing out the big misunderstanding that I had at mktemp and his relatives. Now this is a little easier to solve. Since the linker will prefer the version in the object file, you just need to write mktemp in terms of mkstemp .

The only difficulties are cleaning up the file descriptors that mkstemp will return to you and make everything thread safe. You can use a static array of descriptors and an atexit registered function to clean up, if you can set a limit on the number of temporary files that you need. If not, just use a linked list.

Answer 5

Use mkstemp :

 int fd = mkstemp(template); 

After this call, template will be replaced with the actual file name. You will have a file descriptor and file path.