For these simple utilities, it doesn't harm to make all global variables
static. In fact, this allows the compiler to perform better forms of
optimisation and analysis.
in the system. A simple heuristics is used to detect what is "enough"
memory: if number of physmem pages is greater than 32k (equalling 128 MB
on machines with 4 kB pages).
Typical immediate result of these changes is reduction in context switches
and the goal is to increase efficiency by using large buffers:
before: /usr/bin/time -hlp cat file1 > file2
...
163 voluntary context switches
11194 involuntary context switches
after: /usr/bin/time -hlp ./cat file1 > file2
...
417 voluntary context switches
272 involuntary context switches
Reviewed by: hackers@ (no objections to earlier version of cat patch)
Approved by: gnn (mentor)
MFC after: 4 months
o __P has been reoved
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
they already are.
Approved by: arch@, new style(9)
Restore the code that avoided closing and reopening
stdin. This is also required by POSIX. As a bonus,
enable multiple stdin reads with the -benstv flags,
by resetting the EOF condition on stdin.
mark up a sample invocation, since it is not a command internal to the
described utility.
Do not use Ar (argument) to mark up something which is not an argument
to the utility or one of its internal commands.
This gets rid of a bogus cast of NULL in setbuf().
Lets us know the buffer malloc failed.
Reworks the manpage a bit to make it more mdoc(7) compliant, adds
examples.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
