lib/readline_simple.c

   1 #include <common.h>
   2 #include <watchdog.h>
   3
   4 static char erase_seq[] = "\b \b";              /* erase sequence       */
   5 static char   tab_seq[] = "        ";           /* used to expand TABs  */
   6
   7 static char * delete_char (char *buffer, char *p, int *colp, int *np, int plen)
   8 {
   9         char *s;
  10
  11         if (*np == 0) {
  12                 return (p);
  13         }
  14
  15         if (*(--p) == '\t') {                   /* will retype the whole line   */
  16                 while (*colp > plen) {
  17                         puts (erase_seq);
  18                         (*colp)--;
  19                 }
  20                 for (s=buffer; s<p; ++s) {
  21                         if (*s == '\t') {
  22                                 puts (tab_seq+((*colp) & 07));
  23                                 *colp += 8 - ((*colp) & 07);
  24                         } else {
  25                                 ++(*colp);
  26                                 putchar (*s);
  27                         }
  28                 }
  29         } else {
  30                 puts (erase_seq);
  31                 (*colp)--;
  32         }
  33         (*np)--;
  34         return (p);
  35 }
  36
  37 /*
  38  * Prompt for input and read a line.
  39  * If  CONFIG_BOOT_RETRY_TIME is defined and retry_time >= 0,
  40  * time out when time goes past endtime (timebase time in ticks).
  41  * Return:      number of read characters
  42  *              -1 if break
  43  *              -2 if timed out
  44  */
  45 int readline (const char *prompt, char *line, int len)
  46 {
  47         char   *p = line;
  48         int     n = 0;                          /* buffer index         */
  49         int     plen = 0;                       /* prompt length        */
  50         int     col;                            /* output column cnt    */
  51         char    c;
  52
  53         /* print prompt */
  54         if (prompt) {
  55                 plen = strlen (prompt);
  56                 puts (prompt);
  57         }
  58         col = plen;
  59
  60         for (;;) {
  61 #ifdef CONFIG_BOOT_RETRY_TIME
  62                 while (!tstc()) {       /* while no incoming data */
  63                         if (retry_time >= 0 && get_ticks() > endtime)
  64                                 return (-2);    /* timed out */
  65                 }
  66 #endif
  67                 WATCHDOG_RESET();               /* Trigger watchdog, if needed */
  68
  69 #ifdef CONFIG_SHOW_ACTIVITY
  70                 while (!tstc()) {
  71                         extern void show_activity(int arg);
  72                         show_activity(0);
  73                 }
  74 #endif
  75                 c = getc();
  76
  77                 /*
  78                  * Special character handling
  79                  */
  80                 switch (c) {
  81                 case '\r':                              /* Enter                */
  82                 case '\n':
  83                         *p = '\0';
  84                         puts ("\r\n");
  85                         return (p - line);
  86
  87                 case '\0':                              /* nul                  */
  88                         continue;
  89
  90                 case 0x03:                              /* ^C - break           */
  91                         line[0] = '\0'; /* discard input */
  92                         return (-1);
  93
  94                 case 0x15:                              /* ^U - erase line      */
  95                         while (col > plen) {
  96                                 puts (erase_seq);
  97                                 --col;
  98                         }
  99                         p = line;
 100                         n = 0;
 101                         continue;
 102
 103                 case 0x17:                              /* ^W - erase word      */
 104                         p=delete_char(line, p, &col, &n, plen);
 105                         while ((n > 0) && (*p != ' ')) {
 106                                 p=delete_char(line, p, &col, &n, plen);
 107                         }
 108                         continue;
 109
 110                 case 0x08:                              /* ^H  - backspace      */
 111                 case 0x7F:                              /* DEL - backspace      */
 112                         p=delete_char(line, p, &col, &n, plen);
 113                         continue;
 114
 115                 default:
 116                         /*
 117                          * Must be a normal character then
 118                          */
 119                         if (n < CONFIG_CBSIZE-2) {
 120                                 if (c == '\t') {        /* expand TABs          */
 121                                         puts (tab_seq+(col&07));
 122                                         col += 8 - (col&07);
 123                                 } else {
 124                                         ++col;          /* echo input           */
 125                                         putchar (c);
 126                                 }
 127                                 *p++ = c;
 128                                 ++n;
 129                         } else {                        /* Buffer full          */
 130                                 putchar ('\a');
 131                         }
 132                 }
 133         }
 134 }
 135
 136 /**
 137  * @file
 138  * @brief Primitiv Line Parser
 139  */
 140
 141 /** @page readline_parser Primitive Line Parser
 142  *
 143  * There is still a primtive line parser as a alternative to the hush shell
 144  * environment available. This is for persons who like the old fashion way of
 145  * edititing and command entering.
 146  *
 147  * Enable the "Simple parser" in "General Settings", "Select your shell" to
 148  * get back the old console feeling.
 149  *
 150  */