ref: c0a28bad03c29788d9fc18b5ab56c13a6222bf7d
dir: /appl/cmd/ps.b/
implement Ps; include "sys.m"; include "draw.m"; FD, Dir: import Sys; Context: import Draw; Ps: module { init: fn(ctxt: ref Context, argv: list of string); }; sys: Sys; stderr: ref FD; init(nil: ref Context, nil: list of string) { sys = load Sys Sys->PATH; stderr = sys->fildes(2); sys->pctl(Sys->FORKNS, nil); if(sys->chdir("/prog") < 0){ sys->fprint(stderr, "ps: can't chdir to /prog: %r\n"); raise "fail:no /prog"; } fd := sys->open(".", sys->OREAD); if(fd == nil) { sys->fprint(stderr, "ps: cannot open /prog: %r\n"); raise "fail:no /prog"; } for(;;) { (n, d) := sys->dirread(fd); if(n <= 0){ if(n < 0) { sys->fprint(stderr, "ps: error reading /prog: %r\n"); raise "fail:error on /prog"; } break; } for(i := 0; i < n; i++) if(d[i].name[0] >= '0' && d[i].name[0] <= '9') ps(int d[i].name); } } ps(pid: int) { proc := string pid+"/status"; fd := sys->open(proc, sys->OREAD); if(fd == nil) { # process must have died # sys->fprint(stderr, "ps: /prog/%s: %r\n", proc); return; } buf := array[128] of byte; n := sys->read(fd, buf, len buf); if(n > 0) sys->print("%s\n", string buf[0:n]); }