ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /appl/cmd/promptstring.b/
RAWON_STR := "*"; RAWON : con 0; RAWOFF : con 1; promptstring(prompt, def: string, mode: int): string { if(mode == RAWON || def == nil || def == "") sys->fprint(stdout, "%s: ", prompt); else sys->fprint(stdout, "%s [%s]: ", prompt, def); (eof, resp) := readline(stdin, mode); if(eof) exit; if(resp == "") resp = def; return resp; } readline(fd: ref Sys->FD, mode: int): (int, string) { i: int; eof: int; fdctl: ref Sys->FD; eof = 0; buf := array[128] of byte; tmp := array[128] of byte; if(mode == RAWON){ fdctl = sys->open("/dev/consctl", sys->OWRITE); if(fdctl == nil || sys->write(fdctl,array of byte "rawon",5) != 5){ sys->fprint(stderr, "unable to change console mode"); return (1,nil); } } for(sofar := 0; sofar < 128; sofar += i){ i = sys->read(fd, tmp, 128 - sofar); if(i <= 0){ eof = 1; break; } if(tmp[i-1] == byte '\n'){ for(j := 0; j < i-1; j++){ buf[sofar+j] = tmp[j]; if(mode == RAWON && RAWON_STR != nil) sys->write(stdout,array of byte RAWON_STR,1); } sofar += j; if(mode == RAWON) sys->write(stdout,array of byte "\n",1); break; } else { for(j := 0; j < i; j++){ buf[sofar+j] = tmp[j]; if(mode == RAWON && RAWON_STR != nil) sys->write(stdout,array of byte RAWON_STR,1); } } } if(mode == RAWON) sys->write(fdctl,array of byte "rawoff",6); return (eof, string buf[0:sofar]); }