Chapter 11. Some Simple Streams

Table of Contents
WvFile - accessing Unix files
WvFileWatcher - waiting for a file to change
WvPipe - talking to subtasks
WvModem - baud rates and terminal modes

Let's look at a few streams that are only slightly more complicated than WvStream itself: WvFile, WvFileWatcher, and WvPipe.

WvFile - accessing Unix files

WvFile is the simplest WvStream-derivative around. All it does is open a Unix file for you given a filename, so you don't have to supply the fd yourself.

	  
/*
 * A WvFile example.
 *
 * Some text about this example...
 */

#include <wvfile.h>

int main()
{
    WvFile infile("/etc/passwd", O_RDONLY);
    char *s;
    
    while (infile.isok() && (s = infile.blocking_getline(-1)) != NULL)
    	wvcon->print("%s\n", s);
}

 	 

Need we say more?

Oh, since Unix devices are just files, you can use them with WvFile just as easily. For example, if your modem is /dev/ttyS2, you can connect to it by creating a WvFile that refers to /dev/ttyS2. Of course, the WvModem class is probably more useful for that particular job.