ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /appl/cmd/cmp.b/
implement Cmp; include "sys.m"; sys: Sys; include "draw.m"; draw: Draw; include "arg.m"; BUF: con 65536; stderr: ref Sys->FD; Cmp: module { init: fn(nil: ref Draw->Context, argv: list of string); }; init(nil: ref Draw->Context, args: list of string) { sys = load Sys Sys->PATH; lflag := Lflag := sflag := 0; buf1 := array[BUF] of byte; buf2 := array[BUF] of byte; stderr = sys->fildes(2); arg := load Arg Arg->PATH; if(arg == nil){ sys->fprint(stderr, "cmp: cannot load %s: %r\n", Arg->PATH); raise "fail:load"; } arg->init(args); while((op := arg->opt()) != 0) case op { 'l' => lflag = 1; 'L' => Lflag = 1; 's' => sflag = 1; * => usage(); } args = arg->argv(); arg = nil; if(args == nil) usage(); if(len args < 2) usage(); name1 := hd args; args = tl args; if((f1 := sys->open(name1, Sys->OREAD)) == nil){ sys->fprint(stderr, "cmp: can't open %s: %r\n",name1); raise "fail:open"; } name2 := hd args; args = tl args; if((f2 := sys->open(name2, Sys->OREAD)) == nil){ sys->fprint(stderr, "cmp: can't open %s: %r\n",name2); raise "fail:open"; } if(args != nil){ o := big hd args; if(sys->seek(f1, o, 0) < big 0){ sys->fprint(stderr, "cmp: seek by offset1 failed: %r\n"); raise "fail:seek 1"; } args = tl args; } if(args != nil){ o := big hd args; if(sys->seek(f2, o, 0) < big 0){ sys->fprint(stderr, "cmp: seek by offset2 failed: %r"); raise "fail:seek 2"; } args = tl args; } if(args != nil) usage(); nc := big 1; l := big 1; diff := 0; b1, b2: array of byte; for(;;){ if(len b1 == 0){ nr := sys->read(f1, buf1, BUF); if(nr < 0){ if(!sflag) sys->print("error on %s after %bd bytes\n", name1, nc-big 1); raise "fail:read error"; } b1 = buf1[0: nr]; } if(len b2 == 0){ nr := sys->read(f2, buf2, BUF); if(nr < 0){ if(!sflag) sys->print("error on %s after %bd bytes\n", name2, nc-big 1); raise "fail:read error"; } b2 = buf2[0: nr]; } n := len b2; if(n > len b1) n = len b1; if(n == 0) break; for(i:=0; i<n; i++){ if(Lflag && b1[i]== byte '\n') l++; if(b1[i] != b2[i]){ if(!lflag){ if(!sflag){ sys->print("%s %s differ: char %bd", name1, name2, nc+big i); if(Lflag) sys->print(" line %bd\n", l); else sys->print("\n"); } raise "fail:differ"; } sys->print("%6bd 0x%.2x 0x%.2x\n", nc+big i, int b1[i], int b2[i]); diff = 1; } } nc += big n; b1 = b1[n:]; b2 = b2[n:]; } if(len b1 != len b2) { nc--; if(len b1 > len b2) sys->print("EOF on %s after %bd bytes\n", name2, nc); else sys->print("EOF on %s after %bd bytes\n", name1, nc); raise "fail:EOF"; } if(diff) raise "fail:differ"; exit; } usage() { sys->fprint(stderr, "Usage: cmp [-lsL] file1 file2 [offset1 [offset2] ]\n"); raise "fail:usage"; }