OS(2) OS(2)
NAME
Os - helper module for interfacing with the host OS
SYNOPSIS
include "os.m";
os := load Os Os->PATH;
init: fn();
filename: fn(name: string): string;
run: fn(cmd: string, dir: string): (string, string);
Cmdio: adt {
ifd: ref Sys->FD; # stdin
ofd: ref Sys->FD; # stdout
efd: ref Sys->FD; # stderr
wfd: ref Sys->FD; # wait
cfd: ref Sys->FD; # ctl
};
frun: fn(cmd: string, dir: string): (ref Cmdio, string);
emuhost: string;
emuroot: string;
DESCRIPTION
Os provides operations common in most servers that export
resources from the host OS. The module must be initialized
by calling init before using any of its other facilities.
Filename returns a string for the file named name in a for-
mat understood by the underlying system. In particular, it
takes care of adding the value of $emuhost as a prefix to
the file name given. It is useful to execute host commands
that refer to files known to us, but kept in the host file
system.
Run executes cmd in the host system shell using dir as cur-
rent directory and returns a tuple with the command output
and an error string. The parameter dir may be nil, in which
case the current directory is not changed for the command.
Frun provides is similar to run but returns file descriptors
to let the caller stream input, output, errors, recover the
process wait status, and issue control requests to the pro-
cess. Upon errors frun returns a non-null error string and
a null reference to a descriptor set.
Emuhost and Emuroot keep the value of the respective envi-
ronment variables.
SOURCE
/usr/octopus/port/lib/os.b
OS(2) OS(2)
SEE ALSO
cmd(3).