ref: 02ac617541ca1a7bf82b1615fb5a58235469b5d3
dir: /appl/alphabet/fs/mode.b/
implement Mode, Fsmodule; include "sys.m"; sys: Sys; include "draw.m"; include "sh.m"; include "alphabet/reports.m"; Report: import Reports; include "alphabet/fs.m"; fs: Fs; Value: import fs; Fschan, Fsdata, Entrychan, Entry, Gatechan, Gatequery, Nilentry, Option, Next, Down, Skip, Quit: import Fs; Mode: module {}; # XXX implement octal modes. User: con 8r700; Group: con 8r070; Other: con 8r007; All: con User | Group | Other; Read: con 8r444; Write: con 8r222; Exec: con 8r111; types(): string { return "ps"; } badmod(p: string) { sys->fprint(sys->fildes(2), "fs: size: cannot load %s: %r\n", p); raise "fail:bad module"; } init() { sys = load Sys Sys->PATH; fs = load Fs Fs->PATH; if(fs == nil) badmod(Fs->PATH); fs->init(); } run(nil: ref Draw->Context, nil: ref Report, nil: list of Option, args: list of ref Value): ref Value { spec := (hd args).s().i; (ok, mask, mode) := parsemode(spec); if(ok == 0){ sys->fprint(sys->fildes(2), "fs: mode: bad mode %#q\n", spec); return nil; } c := chan of Gatequery; spawn modegate(c, mask, mode); return ref Value.Vp(c); } modegate(c: Gatechan, mask, mode: int) { m := mode & mask; while((((d, nil, nil), reply) := <-c).t0.t0 != nil) reply <-= ((d.mode & mask) ^ m) == 0; } # stolen from /appl/cmd/chmod.b parsemode(spec: string): (int, int, int) { mask := Sys->DMAPPEND | Sys->DMEXCL | Sys->DMDIR | Sys->DMAUTH; loop: for(i := 0; i < len spec; i++){ case spec[i] { 'u' => mask |= User; 'g' => mask |= Group; 'o' => mask |= Other; 'a' => mask |= All; * => break loop; } } if(i == len spec) return (0, 0, 0); if(i == 0) mask |= All; op := spec[i++]; if(op != '+' && op != '-' && op != '=') return (0, 0, 0); mode := 0; for(; i < len spec; i++){ case spec[i]{ 'r' => mode |= Read; 'w' => mode |= Write; 'x' => mode |= Exec; 'a' => mode |= Sys->DMAPPEND; 'l' => mode |= Sys->DMEXCL; 'd' => mode |= Sys->DMDIR; 'A' => mode |= Sys->DMAUTH; * => return (0, 0, 0); } } if(op == '+' || op == '-') mask &= mode; if(op == '-') mode = ~mode; return (1, mask, mode); }