Greg Woodhouse and I were corresponding about this just recently because of something I was trying to figure out. This particular part I thought might be helpful to you. It explains the "WNS" I see when I am importing routines with %RI - they are parameters.
************** Anyway... When you open a file for writing you normally obtain an exclusive lock (or you can't open it), but if you're just going to throw away the file contents, gaining an exclusive lock *may* not be necessary (hence the "S"[Nancy note- Share]). The "N" (for new version) means you throw away the file contents on all platforms except VMS. On VMS, you would get a series of file versions: TMP.TXT;1, TMP.TXT;2, etc. You can open files for reading, writing or both, but opening a file that doesn't already exist will normally fail: USER>O "/tmp/junk.txt":"RW" O "/tmp/junk.txt":"RW" ^ <INTERRUPT> USER>D ^%CLI CLI command: touch /tmp/junk.txt USER>O "/tmp/junk.txt":"RW" USER>C "/tmp/junk.txt" USER> (The Unix command "touch" just opens and closes a file, having the effect of creating it if it doesn't already exist.) It seems that Cache doesn't have a "C" flag, but "N" is semantically equivalent to passing the "c" flag to fopen() in C. So, if you prefer, just think of "N" as "create". On Wednesday 16 November 2005 10:31 am, K.S. Bhaskar wrote: Eddie / Kevin -- IO parameters in M are different for each implementation (yes, the standard is to be different). You will have more luck with the GT.M Programmers Guide (http://www.sanchez-gtm.com/user_documentation/GTM-PG-UNIX44/index.htm) in this area. -- Bhaskar On Wed, 2005-11-16 at 08:34 -0600, Eddie Hagood wrote: > Hey all, > > This is Kevin T. I am working with Eddie Hagood, who is new in our > office and interested in learning M (Great!). > > We are going through some example codes, and I am having a hard time > explaining the OPEN command. We have R. Walters book, and he gives > examples like this: > OPEN 1,2:("C":"DATAFILE.TXT") > ... > USE 2 READ RECORD > ... > > I, on the other hand, in the past have found and copied code like > this: > SET FNAME="/tmp/mytext.txt" > OPEN FNAME > USE FNAME > WRITE "TEXT OUT GOES HERE." > USE $P > > > I know that OPEN has LOTS of parameters, but I don't understand the > "1,2" above. Is this assigning the output file a device number or > something? > > Also, how do I specify overwriting vs. appending? > > Thanks > Kevin & Eddie. ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today Register for a JBoss Training Course. Free Certification Exam for All Training Attendees Through End of 2005. For more info visit: http://ads.osdn.com/?ad_id=7628&alloc_id=16845&op=click _______________________________________________ Hardhats-members mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/hardhats-members -- Nancy Anthracite ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today Register for a JBoss Training Course. Free Certification Exam for All Training Attendees Through End of 2005. For more info visit: http://ads.osdn.com/?ad_id=7628&alloc_id=16845&op=click _______________________________________________ Hardhats-members mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/hardhats-members
