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Member "showkey-1.8/showkey.c" (27 Jan 2017, 2785 Bytes) of package /linux/misc/showkey-1.8.tar.gz:

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    1 /*
    2  * showkey.c -- display cooked key sequences
    3  *
    4  * Invoke this (no arguments needed) to see keycap-to-keystrokes mappings.
    5  *
    6  * by Eric S. Raymond <esr@snark.thyrsus.com>.
    7  */
    8 #include <stdio.h>
    9 #include <termios.h>
   10 #include <signal.h>
   11 #include <string.h>
   12 #include <stdbool.h>
   13 #include <stdlib.h>
   14 #include <unistd.h>
   15 
   16 #define ALT 0x80
   17 #define ESC 0x1b
   18 
   19 static char *lowchars[] =
   20 {
   21     "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
   22     "BS",  "HT",  "LF",  "VT",  "FF",  "CR",  "SO",  "SI",
   23     "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
   24     "CAN", "EM",  "SUB", "ESC", "FS",  "GS",  "RS",  "US",
   25     "SP",
   26 };
   27 
   28 static int signalled;
   29 
   30 static void catcher(const int sig)
   31 {
   32     signalled = sig;
   33 }
   34 
   35 #define STARTCOOKIE   '<'
   36 #define ENDCOOKIE     '>'
   37 
   38 static void visualize(int c, /*@out@*/char *buf)
   39 {
   40     char *end;
   41     bool unprintable;
   42 
   43     buf[0] = '\0';
   44     if ((c & ALT) != 0) {
   45     unprintable = true;
   46     c &=~ ALT;
   47     buf[0] = STARTCOOKIE;
   48     buf[1] = '\0';
   49     (void) strcat(buf, "ALT-");
   50     }
   51 
   52     if (c <= ' ') {
   53     unprintable = true;
   54     end = buf + strlen(buf);
   55     if (buf[0] != STARTCOOKIE) {
   56         *end++ = STARTCOOKIE;
   57         *end++ = '\0';
   58     } if (c > 0 && c < 27) {
   59         (void) strcat(buf, "CTL-");
   60         end = buf + strlen(buf);
   61         *end++ = (c + 0x40);
   62         *end++ = '=';
   63         *end = 0;
   64     }
   65     (void) strcat(buf, lowchars[c]);
   66     }
   67     else if (c == 0x3F) {
   68     unprintable = true;
   69     (void) strcat(buf, "DEL");
   70     } else {
   71     unprintable = false;
   72     buf[0] = c;
   73     buf[1] = '\0';
   74     }
   75 
   76     if (unprintable) {
   77     end = buf + strlen(buf);
   78     *end++ = ENDCOOKIE;
   79     *end++ = '\0';
   80     }
   81 }
   82 
   83 
   84 int main()
   85 {
   86     struct termios  cooked, raw;
   87     unsigned char   c;
   88     int i;
   89     char intrchar[32], quitchar[32];
   90 
   91     /*@-unrecog@*/
   92     for (i = SIGHUP; i <= SIGIO; i++)
   93     (void) signal(i, catcher);
   94     /*@=unrecog@*/
   95 
   96     // Get the state of the tty 
   97     (void) tcgetattr(0, &cooked);
   98     // Make a copy we can mess with
   99     (void) memcpy(&raw, &cooked, sizeof(struct termios));
  100     // Turn off echoing, linebuffering, and special-character processing,
  101     // but not the SIGINT or SIGQUIT keys.
  102     raw.c_lflag &=~ (ICANON | ECHO);
  103     // Ship the raw control blts
  104     (void) tcsetattr(0, TCSANOW, &raw);
  105 
  106     (void) printf("Type any key to see the sequence it sends.\n");
  107     visualize(raw.c_cc[VINTR], intrchar);
  108     visualize(raw.c_cc[VQUIT], quitchar);
  109     (void) printf("Terminate with your shell interrupt %s or quit %s character.\n",
  110           intrchar, quitchar);
  111     signalled = 0;
  112     while (signalled == 0)
  113     {
  114     char cbuf[32];
  115 
  116     (void)read(0, &c, 1);
  117     visualize(c, cbuf);
  118     (void)fputs(cbuf, stdout);
  119     (void) fflush(stdout);
  120     }
  121 
  122     (void) printf("\nBye...\n");
  123     // Restore the cooked state
  124     (void) tcsetattr(0, TCSANOW, &cooked);
  125     exit(0);
  126 }
  127 
  128 /* showkey.c ends here */