/dev/null
 

hi all,
I am running a c++ program on linux...
I want to direct my output to /dev/null.
As,
printf("Could not open port \"%s\" at \"%d\" baud.\n"
,com_dev_ptr,DEFAULT_BAUDRATE) > /dev/null;

It gives an error as:parse error before '/' token...
Can anyone please guide me how to direct my output to /dev/null..


Thanks,
Divya

Hi,
I am not an expert, but i believe you should be opening a file handle for /dev/null and write the string to the filehandle.

--sam

Wouldn't it be easier to just comment out the print statement? Why waste your resources writing to /dev/null when all you want is to not generate the output?

In any case, if you really want to write to /dev/null, you need to open /dev/null as an output stream, say _null, and then use fprintf(_null, . . .) to waste your cpu cycles.

Hi,
Thanks a lot....I cannot actally avoid printf statements in my code..I tried but,it did'nt worked successfully..
So,i tried the other option..
I did :
FILE *_null;
_null= fopen ("/dev/null","w");
fprintf(_null,.................);
But,it is giving error as:
error: conflicting types for `_null'
error: previous declaration of `_null'
warning: data definition has no type or storage class
In function `probe_lcm':
warning: passing arg 1 of `fprintf' makes pointer from integer without a cast
In function `main':
warning: passing arg 1 of `fclose' makes pointer from integer without a cast

I am just new in using C++..can you please guide where i m wrong..
How can i sove this prob...

Thanks,Divya

This is one of the silliest things I have ever heard of; opening /dev/null in a program to write to it. :rolleyes:

But you should get away from _null as a file handle name. The message is telling you that you can't do that. Someplace buried in an include or something, _null is already defined. You should expect that because null has a specific meaning in C programs, and the underscore is very commonly used as a prefix in the include files. Change it to something unique, such as FILE *mycpucyclewastingnullfilepointer. That'll work.

Hi,
Thanks for the reply......:)
Now,I have changed the code as:

FILE *mycpu1;
mycpu1= fopen("/DB/file1","w");
-----------------
fprintf(mycpu1,.................);
-----------------
fclose (mycpu1);

still getting these errors:
error: conflicting types for `mycpu1'
lcm-serial-test3.c:27: error: previous declaration of `mycpu1'
lcm-serial-test3.c:28: warning: data definition has no type or storage class
lcm-serial-test3.c: In function `probe_lcm':
lcm-serial-test3.c:121: warning: passing arg 1 of `fprintf' makes pointer from integer without a cast
lcm-serial-test3.c: In function `main':
lcm-serial-test3.c:279: warning: passing arg 1 of `fclose' makes pointer from integer without a cast

same errors again....:confused:



Thanks,Divya

man fopen()