On Feb 6, 2006, at 6:45 PM, Gregory Woodhouse wrote:
On Feb 6, 2006, at 6:02 PM, Steven McPhelan wrote:
You never want to READ from the NULL device, especially with
something like "Press return to continue" as the application may
get stuck in a infinite READ loop especially if the READ answer is
required.
I see what you mean. Even with a * or # read (both forbidden by the
SAC), a read from NULL should fail immediately. Even so, a lot of
programmers interpret a null result to mean the user just pressed
enter. At any rate, having code that does anything of this sort in
a data dictionary is VERY strange (which isn't to say it's never
happened).
Out of curiosity, I tested this in Cache (no Kernel involved)
csession cache
USER>O "/dev/null"
USER>U "/dev/null" R X#1
USER>W $L(X)
0
It seems to me much more sensible to raise an error when EOF is
encountered than just return an empty string, but a lot of code
seems to assume that trying to read past EOF will just silently.
Just for fun, this is C
~:$ cat test.c
#include <stdio.h>
int main()
{
FILE *fp;
int c;
fp = fopen("/dev/null", "r");
if ((c = fgetc(fp)) == EOF)
printf("end of file!\n");
}
~:$ cc test.c
~:$ a.out
end of file!
~:$
===
Gregory Woodhouse
[EMAIL PROTECTED]
"The most profound technologies are those that disappear."
--Mark Weiser
-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems? Stop! Download the new AJAX search engine that makes
searching your log files as easy as surfing the web. DOWNLOAD SPLUNK!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642
_______________________________________________
Hardhats-members mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/hardhats-members
