On Aug 17, 2013, at 05:40, Steffen Prohaska wrote:

Previously, filtering more than 2GB through an external filter (see
test) failed on Mac OS X 10.8.4 (12E55) with:

   error: read from external filter cat failed
   error: cannot feed the input to external filter cat
   error: cat died of signal 13
   error: external filter cat failed 141
   error: external filter cat failed

The reason is that read() immediately returns with EINVAL if len >= 2GB.
I haven't found any information under which specific conditions this

According to POSIX [1] for read:

If the value of nbyte is greater than {SSIZE_MAX}, the result is implementation-defined.

The write function also has the same restriction [2].

Since OS X still supports running 32-bit executables, and SSIZE_MAX is 2GB - 1 when running 32-bit it would seem the same limit has been imposed on 64-bit executables. In any case, we should avoid "implementation-defined" behavior for portability unless we know the OS we were compiled on has acceptable "implementation-defined" behavior and otherwise never attempt to read or write more than SSIZE_MAX bytes.

[1] http://pubs.opengroup.org/onlinepubs/009695399/functions/read.html
[2] http://pubs.opengroup.org/onlinepubs/009695399/functions/write.html
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