sys/src/cmd/cryptsetup/readcons.c

   1 /* From /sys/src/libauthsrv/readnvram.c, LPL licensed */
   2 #include <u.h>
   3 #include <libc.h>
   4
   5
   6 char*
   7 readcons(char *prompt, char *def, int raw, char *buf, int nbuf)
   8 {
   9         int fdin, fdout, ctl, n, m;
  10         char line[10];
  11
  12         fdin = open("/dev/cons", OREAD);
  13         if(fdin < 0)
  14                 fdin = 0;
  15         fdout = open("/dev/cons", OWRITE);
  16         if(fdout < 0)
  17                 fdout = 1;
  18         if(def != nil)
  19                 fprint(fdout, "%s[%s]: ", prompt, def);
  20         else
  21                 fprint(fdout, "%s: ", prompt);
  22         if(raw){
  23                 ctl = open("/dev/consctl", OWRITE);
  24                 if(ctl >= 0)
  25                         write(ctl, "rawon", 5);
  26         } else
  27                 ctl = -1;
  28
  29         m = 0;
  30         for(;;){
  31                 n = read(fdin, line, 1);
  32                 if(n == 0){
  33                         close(ctl);
  34                         werrstr("readcons: EOF");
  35                         return nil;
  36                 }
  37                 if(n < 0){
  38                         close(ctl);
  39                         werrstr("can't read cons");
  40                         return nil;
  41                 }
  42                 if(line[0] == 0x7f)
  43                         exits(0);
  44                 if(n == 0 || line[0] == '\n' || line[0] == '\r'){
  45                         if(raw){
  46                                 write(ctl, "rawoff", 6);
  47                                 write(fdout, "\n", 1);
  48                                 close(ctl);
  49                         }
  50                         buf[m] = '\0';
  51                         if(buf[0]=='\0' && def)
  52                                 strcpy(buf, def);
  53                         return buf;
  54                 }
  55                 if(line[0] == '\b'){
  56                         if(m > 0)
  57                                 m--;
  58                 }else if(line[0] == 0x15){      /* ^U: line kill */
  59                         m = 0;
  60                         if(def != nil)
  61                                 fprint(fdout, "%s[%s]: ", prompt, def);
  62                         else
  63                                 fprint(fdout, "%s: ", prompt);
  64                 }else{
  65                         if(m >= nbuf-1){
  66                                 fprint(fdout, "line too long\n");
  67                                 m = 0;
  68                                 if(def != nil)
  69                                         fprint(fdout, "%s[%s]: ", prompt, def);
  70                                 else
  71                                         fprint(fdout, "%s: ", prompt);
  72                         }else
  73                                 buf[m++] = line[0];
  74                 }
  75         }
  76 }
  77