Is there a "garbage" stream?

[sewilli]

Hi,

Here's my problem. I have C code that does a bunch of number crunching, spitting out intermediate results to the output files along the way. However, in some applications, it would be preferable to NOT write any data to output files (e.g., when the program is run iteratively in an nonlinear optimization routine).

Rather than hunt through my code to find all the instances of fprintf(fpout, ...) and insert a conditional statement, it would be much easier (and cleaner) if I could simply initialize the file pointer to a stream going nowhere.

I've tried setting fpout = NULL but that doesn't work. Any suggestions?

Scott

[Dave_Sinkula]

7.19.4.3 The tmpfile function

Synopsis
1 #include <stdio.h>
FILE *tmpfile(void);

Description
2 The tmpfile function creates a temporary binary file that is different from any other existing file and that will automatically be removed when it is closed or at program termination. If the program terminates abnormally, whether an open temporary file is removed is implementation-defined. The file is opened for update with "wb+" mode.

Recommended practice
It should be possible to open at least TMP_MAX temporary files during the lifetime of the program (this limit may be shared with tmpnam) and there should be no limit on the number simultaneously open other than this limit and any limit on the number of open files (FOPEN_MAX).

Returns
3 The tmpfile function returns a pointer to the stream of the file that it created. If the file cannot be created, the tmpfile function returns a null pointer.

[sewilli]

Originally posted by Salem
Which OS are you using, and which compiler?

Do you start with
fpout = fopen( "somefile", "w" );

OS = Win2K
Compiler = MingW (gcc)

Yes, that's exactly the syntax.

Scott

[sewilli]

Thanks for the info on tmpfile()--hadn't seen that before. It does the job, though I'm concerned the size of the temp file could get unruly before it goes away.

Scott

[sewilli]

Thanks to all!