Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!dftsrv!news
From: news@dftsrv.gsfc.nasa.gov (news)
Newsgroups: comp.os.minix
Subject: Re: Minimal version of C-Library in MINIX-ST??
Keywords: fopen dumb
Message-ID: <198@dftsrv.gsfc.nasa.gov>
Date: 5 May 89 10:54:17 GMT
References: <284@nixpbe.UUCP>
Reply-To: stailey@iris613.UUCP (Ken Stailey)
Organization: Goddard Space Flight Center Climate and Radiation Branch
Lines: 56

+
In article <284@nixpbe.UUCP> mboen@nixpbe.UUCP (Martin Boening) writes:
+>[stuff del'd] noticed that for **NIX-like systems the following opening modes
+>for files are defined:
+>
+>> #define Z_READ  "r"
+>> #define Z_WRITE "r+"
+>> #define Z_RDWR  "r+"
+>> #define Z_NEW   "w"
+>
+>In the Minix sources the fopen-Routine doesn't scan the whole modestring
+>though. It just looks at the first character. As a result, only three modes
+>are supported:
+>
+> 'w' -> create file
+> 'r' -> read file
+> 'a' -> write to file (append)
+>
+>i.e with mode 'w', creat is called, with 'r' an 'open (fn, 0)' and with 'w'
+>an 'open (fn, 1)'.
+>
+>All, open does is a 'callm3(FS,OPEN,mode,name)'. Looking at do_open I saw
+>that 3 modes are supported:
+>
+>  0    read file
+>  1    write file
+>  2    read and write file <--!!!
+>
+>So, why can't fopen do an 'open (fn, 2)' to open a file for reading and
+>writing when the modestring contains "r+" or "w+". I tried this and now
+>zoo seems to work alright (some problems with the time settings remain
+>[did you know that yesterday was may 1st, 1997?:-)])
+>
+>My question: is the library supplied with MINIX-ST a minimal version? Has
+>this been fixed? Does anybody know what GCC does and if it handles this
+>better? Does anybody know of problems that might occur when opening a file
+>for reading and writing using fopen (buffer problems, etc.) Does anybody
+>even care to comment ? :-)
From: stailey@iris613.gsfc.nasa.gov (Ken Stailey)
Path: iris613!stailey

  What did the real version 7 have?  Maybe it was somewhat small (primitive)
just like MINIX.

  If I have some time this weekend I will try to re-write fopen().  I made
freopen() for my MINIX in order to bring up some forgotten application;
a modern fopen() can't be that hard, because it's so high level.

  I tried to bring up GCC but decided that it was not in the MINIX style
because it was too big.  (Also I only have 5 meg reserved on my HD for MINIX)

							Ken

*========================================================================*
{  eat more disclaimer                           ken@all.over.the.place  }
*========================================================================*