From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: fgets behaviour after eof
Date: Wed, 27 Aug 2014 13:16:20 +0200 [thread overview]
Message-ID: <20140827111620.GY22308@port70.net> (raw)
the C standard requires that
"If end-of-file is encountered and no characters have been read into the
array, the contents of the array remain unchanged and a null pointer is
returned. If a read error occurs during the operation, the array contents
are indeterminate and a null pointer is returned."
but musl's fgets always terminates the buffer with \0 even after EOF,
this is easy to fix:
- *p = 0;
+ if (s) *p = 0;
However the behaviour of fgets(s, 1, f) is unclear if feof(f) is true,
in this case nothing is read so fgets cannot "encounter" end-of-file,
so it may set s[0]=0 and return s or it could check feof and return 0.
(glibc does not check feof)
next reply other threads:[~2014-08-27 11:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-27 11:16 Szabolcs Nagy [this message]
2014-08-27 16:52 ` Rich Felker
2014-08-27 17:14 ` Rich Felker
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