ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /appl/cmd/runas.b/
implement Runas; include "sys.m"; include "draw.m"; include "sh.m"; sys: Sys; sh: Sh; Context: import sh; Runas: module { init: fn(nil: ref Draw->Context, argv: list of string); }; init(drawctxt: ref Draw->Context, argv: list of string) { sys = load Sys Sys->PATH; sh = load Sh Sh->PATH; if (sh == nil) badmodule(Sh->PATH); if (len argv < 3) usage(); argv = tl argv; user := hd argv; argv = tl argv; fd := sys->open("/dev/user", Sys->OWRITE); if (fd == nil) error(sys->sprint("cannot open /dev/user: %r")); u := array of byte user; if (sys->write(fd, u, len u) != len u) error(sys->sprint("cannot set user: %r")); sh->run(drawctxt, argv); } badmodule(p: string) { sys->fprint(stderr(), "runas: cannot load %s: %r\n", p); raise "fail:bad module"; } stderr(): ref Sys->FD { return sys->fildes(2); } usage() { sys->fprint(stderr(), "usage: runas user cmd [args...]\n"); raise "fail:usage"; } error(e: string) { sys->fprint(stderr(), "runas: %s\n", e); raise "fail:error"; }