hexedit: restore screen on exit

function                                             old     new   delta
hexedit_main                                         998    1082     +84
restore_term                                           -      29     +29
remap                                                168     173      +5
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/0 up/down: 118/0)             Total: 118 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/miscutils/hexedit.c b/miscutils/hexedit.c
index e8bc73b7ed612830ef503b6c43fcb0b9012a97f3..b8627e826bcb0f9333bfcb89bd51524511f371de 100644 (file)
--- a/miscutils/hexedit.c
+++ b/miscutils/hexedit.c
@@ -15,19 +15,28 @@
 
 #include "libbb.h"
 
-#define ESC    "\033"
-#define HOME   ESC"[H"
-#define CLEAR  ESC"[H"ESC"[J"
+#define ESC            "\033"
+#define HOME           ESC"[H"
+#define CLEAR          ESC"[H"ESC"[J"
+#define SET_ALT_SCR    ESC"[?1049h"
+#define POP_ALT_SCR    ESC"[?1049l"
+
+#undef CTRL
+#define CTRL(c)  ((c) & (uint8_t)~0x60)
 
 struct globals {
        smallint half;
+       smallint in_read_key;
        int fd;
        unsigned height;
+       unsigned row;
        uint8_t *addr;
        uint8_t *current_byte;
        uint8_t *eof_byte;
        off_t size;
        off_t offset;
+       /* needs to be zero-inited, thus keeping it in G: */
+       char read_key_buffer[KEYCODE_BUFFER_SIZE];
        struct termios orig_termios;
 };
 #define G (*ptr_to_globals)
@@ -41,6 +50,24 @@ struct globals {
 /* "12ef5670 (xx )*16 _1_3_5_7_9abcdef\n"NUL */
 #define LINEBUF_SIZE (8 + 1 + 3*16 + 16 + 1 + 1 /*paranoia:*/ + 13)
 
+static void restore_term(void)
+{
+       tcsetattr_stdin_TCSANOW(&G.orig_termios);
+       printf(POP_ALT_SCR);
+       fflush_all();
+}
+
+static void sig_catcher(int sig)
+{
+       if (!G.in_read_key) {
+               /* now it's not safe to do I/O, just inform the main loop */
+               bb_got_signal = sig;
+               return;
+       }
+       restore_term();
+       kill_myself_with_sig(sig);
+}
+
 static int format_line(char *hex, uint8_t *data, off_t offset)
 {
        int ofs_pos;
@@ -141,9 +168,10 @@ static void remap(unsigned cur_pos)
                G.fd,
                G.offset
        );
-       if (G.addr == MAP_FAILED)
-//TODO: restore termios?
+       if (G.addr == MAP_FAILED) {
+               restore_term();
                bb_perror_msg_and_die("mmap");
+       }
 
        G.current_byte = G.addr + cur_pos;
 
@@ -201,12 +229,6 @@ static void move_mapping_lower(void)
        remap(pos);
 }
 
-static void sig_catcher(int sig)
-{
-       tcsetattr_stdin_TCSANOW(&G.orig_termios);
-       kill_myself_with_sig(sig);
-}
-
 //usage:#define hexedit_trivial_usage
 //usage:       "FILE"
 //usage:#define hexedit_full_usage "\n\n"
@@ -214,8 +236,6 @@ static void sig_catcher(int sig)
 int hexedit_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int hexedit_main(int argc UNUSED_PARAM, char **argv)
 {
-       unsigned row = 0;
-
        INIT_G();
 
        get_terminal_width_height(-1, NULL, &G.height);
@@ -237,7 +257,7 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
 
        remap(0);
 
-       printf(CLEAR);
+       printf(SET_ALT_SCR);
        redraw();
        printf(ESC"[1;10H"); /* position on 1st hex byte in first line */
 
@@ -245,21 +265,22 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
        //Backspace: undo
        //Enter: goto specified position
        //Ctrl-L: redraw
-       //Ctrl-X: save and exit (maybe also Q?)
        //Ctrl-Z: suspend
        //'/', Ctrl-S: search
-//TODO: go to end-of-screen on exit (for this, sighandler should interrupt read_key())
 //TODO: detect window resize
-//TODO: read-only mode if open(O_RDWR) fails? hide cursor in this case?
 
        for (;;) {
-               char read_key_buffer[KEYCODE_BUFFER_SIZE];
                unsigned cnt;
-               int32_t key;
+               int32_t key = key; // for compiler
                uint8_t byte;
 
                fflush_all();
-               key = read_key(STDIN_FILENO, read_key_buffer, -1);
+               G.in_read_key = 1;
+               if (!bb_got_signal)
+                       key = read_key(STDIN_FILENO, G.read_key_buffer, -1);
+               G.in_read_key = 0;
+               if (bb_got_signal)
+                       key = CTRL('X');
 
                cnt = 1;
                switch (key) {
@@ -329,9 +350,9 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
                        }
  down:
                        putchar('\n'); /* down one line, possibly scroll screen */
-                       row++;
-                       if (row >= G.height) {
-                               row--;
+                       G.row++;
+                       if (G.row >= G.height) {
+                               G.row--;
                                redraw_cur_line();
                        }
                        if (--cnt)
@@ -371,8 +392,8 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
                        }
                        G.current_byte -= 16;
  up:
-                       if (row != 0) {
-                               row--;
+                       if (G.row != 0) {
+                               G.row--;
                                printf(ESC"[A"); /* up (won't scroll) */
                        } else {
                                //printf(ESC"[T"); /* scroll up */ - not implemented on Linux VT!
@@ -382,8 +403,12 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
                        if (--cnt)
                                goto k_up;
                        break;
-               }
-       }
+               case CTRL('X'):
+                       restore_term();
+                       return EXIT_SUCCESS;
+               } /* switch */
+       } /* for (;;) */
 
+       /* not reached */
        return EXIT_SUCCESS;
 }

diff --git a/miscutils/less.c b/miscutils/less.c
index 241f7f8ba1fbb68e4a70993b437edb0e24683a04..f869a9e82828fe7b08236c1c5a42ca3156e7c050 100644 (file)
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -1103,7 +1103,7 @@ static int64_t getch_nowait(void)
                        goto again;
                }
                /* EOF/error (ssh session got killed etc) */
-               less_exit(0);
+               less_exit(EXIT_SUCCESS);
        }
        set_tty_cooked();
        return key64;