*: use _exit() in sighandlers; showkey: do not use exit-thru-sighandler

[platform/upstream/busybox.git] / console-tools / showkey.c

diff --git a/console-tools/showkey.c b/console-tools/showkey.c
index 149ea64..b29c84d 100644 (file)
--- a/console-tools/showkey.c
+++ b/console-tools/showkey.c
@@ -10,27 +10,7 @@
 #include "libbb.h"
 #include <linux/kd.h>
 
-// set raw tty mode
-// also used by microcom
-// libbb candidates?
-static void xget1(struct termios *t, struct termios *oldt)
-{
-       tcgetattr(STDIN_FILENO, oldt);
-       *t = *oldt;
-       cfmakeraw(t);
-}
-
-static void xset1(struct termios *tio)
-{
-       int ret = tcsetattr(STDIN_FILENO, TCSAFLUSH, tio);
-       if (ret) {
-               bb_perror_msg("can't tcsetattr for stdin");
-       }
-}
 
-/*
- * GLOBALS
- */
 struct globals {
        int kbmode;
        struct termios tio, tio0;
@@ -44,13 +24,22 @@ struct globals {
 } while (0)
 
 
-static void signal_handler(int signo)
+// set raw tty mode
+// also used by microcom
+// libbb candidates?
+static void xget1(struct termios *t, struct termios *oldt)
 {
-       // restore keyboard and console settings
-       xset1(&tio0);
-       xioctl(STDIN_FILENO, KDSKBMODE, (void *)(ptrdiff_t)kbmode);
-       // alarmed? -> exit 0
-       exit(SIGALRM == signo);
+       tcgetattr(STDIN_FILENO, oldt);
+       *t = *oldt;
+       cfmakeraw(t);
+}
+
+static void xset1(struct termios *t)
+{
+       int ret = tcsetattr(STDIN_FILENO, TCSAFLUSH, t);
+       if (ret) {
+               bb_perror_msg("can't tcsetattr for stdin");
+       }
 }
 
 int showkey_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -62,20 +51,21 @@ int showkey_main(int argc UNUSED_PARAM, char **argv)
                OPT_s = (1<<2), // display only the raw scan-codes
        };
 
+       INIT_G();
+
        // FIXME: aks are all mutually exclusive
        getopt32(argv, "aks");
 
-       INIT_G();
-
        // get keyboard settings
        xioctl(STDIN_FILENO, KDGKBMODE, &kbmode);
        printf("kb mode was %s\n\nPress any keys. Program terminates %s\n\n",
                kbmode == K_RAW ? "RAW" :
                        (kbmode == K_XLATE ? "XLATE" :
                                (kbmode == K_MEDIUMRAW ? "MEDIUMRAW" :
-                                       (kbmode == K_UNICODE ? "UNICODE" : "?UNKNOWN?")))
-               , (option_mask32 & OPT_a) ? "when CTRL+D pressed" : "10s after last keypress"
+                                       (kbmode == K_UNICODE ? "UNICODE" : "UNKNOWN")))
+               , (option_mask32 & OPT_a) ? "on EOF (ctrl-D)" : "10s after last keypress"
        );
+
        // prepare for raw mode
        xget1(&tio, &tio0);
        // put stdin in raw mode
@@ -83,34 +73,37 @@ int showkey_main(int argc UNUSED_PARAM, char **argv)
 
        if (option_mask32 & OPT_a) {
                unsigned char c;
+
                // just read stdin char by char
-               while (1 == safe_read(STDIN_FILENO, &c, 1)) {
+               while (1 == read(STDIN_FILENO, &c, 1)) {
                        printf("%3u 0%03o 0x%02x\r\n", c, c, c);
                        if (04 /*CTRL-D*/ == c)
                                break;
                }
        } else {
-               // we should exit on any signal
-               bb_signals(BB_FATAL_SIGS, signal_handler);
                // set raw keyboard mode
                xioctl(STDIN_FILENO, KDSKBMODE, (void *)(ptrdiff_t)((option_mask32 & OPT_k) ? K_MEDIUMRAW : K_RAW));
 
+               // we should exit on any signal; signals should interrupt read
+               bb_signals_recursive_norestart(BB_FATAL_SIGS, record_signo);
+
                // read and show scancodes
-               while (1) {
+               while (!bb_got_signal) {
                        char buf[18];
                        int i, n;
+
                        // setup 10s watchdog
                        alarm(10);
                        // read scancodes
                        n = read(STDIN_FILENO, buf, sizeof(buf));
                        i = 0;
                        while (i < n) {
-                               char c = buf[i];
-                               // show raw scancodes ordered? ->
                                if (option_mask32 & OPT_s) {
+                                       // show raw scancodes
                                        printf("0x%02x ", buf[i++]);
-                               // show interpreted scancodes (default) ? ->
                                } else {
+                                       // show interpreted scancodes (default)
+                                       char c = buf[i];
                                        int kc;
                                        if (i+2 < n
                                         && (c & 0x7f) == 0
@@ -130,9 +123,9 @@ int showkey_main(int argc UNUSED_PARAM, char **argv)
                }
        }
 
-       // cleanup
-       signal_handler(SIGALRM);
+       // restore keyboard and console settings
+       xset1(&tio0);
+       xioctl(STDIN_FILENO, KDSKBMODE, (void *)(ptrdiff_t)kbmode);
 
-       // should never be here!
        return EXIT_SUCCESS;
 }