On February 25, 2014 12:27:41 AM CET, Stuart Henderson <s...@spacehopper.org> wrote: >On 2014-02-24, Fabian Raetz <fabian.ra...@gmail.com> wrote: >> Hi misc@, >> >> while calculating my phys. memory (mb) with the >> folllowing shellsript i get as a result -424. >> >> sysctl -n hw.physmem returns 3849830400 >> >> ------------ >> #!/bin/sh >> >> phys_mem_bytes=`sysctl -n hw.physmem` >> phys_mem_mb=`expr $phys_mem_bytes / 1024 / 1024` >> echo $phys_mem_mb >> ---------- >> >> so i tried >> expr 2147483647 / 2 which returns 1073741824 while >> expr 2147483648 / 2 returns -1073741824 >> >> >> ksh(1) states that expr does Integer arithmetic. >> So is this the expected behaviour or a bug? > >I don't see this discussed in ksh(1) - it's expr(1), /bin/expr on >OpenBSD.
IIRC i386 differs from amd64 (and other arches too). /Alexander >This uses 32-bit signed integer types, which are limited to 2^31-1, >above >which it wraps around. > >It may be possible to change this after we're done with release, but >for >now here's a quick workaround: > >phys_mem_mb=`perl -e "print int($phys_mem_bytes / 1024 / 1024);"`
