lineedit: implement Unicode-aware line editing (optional)

When off:

function                                             old     new   delta
input_delete                                         133     140      +7
vi_word_motion                                       236     240      +4
vi_Back_motion                                        89      92      +3
vi_end_motion                                        223     225      +2
cmdedit_set_out_char                                  74      76      +2
vi_back_motion                                       198     199      +1
vi_Word_motion                                        87      88      +1
vi_End_motion                                         92      86      -6
read_line_input                                     6293    6270     -23
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 7/2 up/down: 20/-29)             Total: -9 bytes

When on:

lineedit_read_key                                    146     272    +126
BB_PUTCHAR                                             -      94     +94
read_line_input                                     6293    6351     +58
save_string                                            -      43     +43
wcstombs                                               -      38     +38
mbstowcs                                               -      38     +38
save_command_ps_at_cur_history                        65      93     +28
input_delete                                         133     148     +15
vi_Back_motion                                        89      90      +1
vi_Word_motion                                        87      86      -1
cmdedit_set_out_char                                  74      73      -1
vi_End_motion                                         92      84      -8
vi_back_motion                                       198     187     -11
vi_word_motion                                       236     206     -30
vi_end_motion                                        223     184     -39
------------------------------------------------------------------------------
(add/remove: 4/0 grow/shrink: 5/6 up/down: 441/-90)           Total: 351 bytes

There is one TODO and maybe some bugs :)

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

1 files changed, 235 insertions, 97 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index ccffedced..e5d0c1b6c 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -33,32 +33,26 @@
  *
  * PS1='\[\033[01;32m\]\u@\h\[\033[01;34m\] \w \$\[\033[00m\] '
  */
-
 #include "libbb.h"
-
+#if ENABLE_FEATURE_ASSUME_UNICODE
+# include <wchar.h>
+# include <wctype.h>
+#endif
 
 /* FIXME: obsolete CONFIG item? */
 #define ENABLE_FEATURE_NONPRINTABLE_INVERSE_PUT 0
 
-
 #ifdef TEST
-
-#define ENABLE_FEATURE_EDITING 0
-#define ENABLE_FEATURE_TAB_COMPLETION 0
-#define ENABLE_FEATURE_USERNAME_COMPLETION 0
-#define ENABLE_FEATURE_NONPRINTABLE_INVERSE_PUT 0
-
-#endif  /* TEST */
+# define ENABLE_FEATURE_EDITING 0
+# define ENABLE_FEATURE_TAB_COMPLETION 0
+# define ENABLE_FEATURE_USERNAME_COMPLETION 0
+# define ENABLE_FEATURE_NONPRINTABLE_INVERSE_PUT 0
+#endif
 
 
 /* Entire file (except TESTing part) sits inside this #if */
 #if ENABLE_FEATURE_EDITING
 
-#if ENABLE_LOCALE_SUPPORT
-#define Isprint(c) isprint(c)
-#else
-#define Isprint(c) ((c) >= ' ' && (c) != ((unsigned char)'\233'))
-#endif
 
 #define ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR \
         (ENABLE_FEATURE_USERNAME_COMPLETION || ENABLE_FEATURE_EDITING_FANCY_PROMPT)
@@ -68,6 +62,38 @@
 #define IF_FEATURE_GETUSERNAME_AND_HOMEDIR(...) __VA_ARGS__
 #endif
 
+
+#undef CHAR_T
+#if ENABLE_FEATURE_ASSUME_UNICODE
+# define BB_NUL L'\0'
+# define CHAR_T wchar_t
+# define BB_isspace(c) iswspace(c)
+# define BB_isalnum(c) iswalnum(c)
+# define BB_ispunct(c) iswpunct(c)
+# define BB_isprint(c) iswprint(c)
+/* this catches bugs */
+# undef isspace
+# undef isalnum
+# undef ispunct
+# undef isprint
+# define isspace isspace_must_not_be_used
+# define isalnum isalnum_must_not_be_used
+# define ispunct ispunct_must_not_be_used
+# define isprint isprint_must_not_be_used
+#else
+# define BB_NUL '\0'
+# define CHAR_T char
+# define BB_isspace(c) isspace(c)
+# define BB_isalnum(c) isalnum(c)
+# define BB_ispunct(c) ispunct(c)
+# if ENABLE_LOCALE_SUPPORT
+#  define BB_isprint(c) isprint(c)
+# else
+#  define BB_isprint(c) ((c) >= ' ' && (c) != ((unsigned char)'\233'))
+# endif
+#endif
+
+
 enum {
         /* We use int16_t for positions, need to limit line len */
         MAX_LINELEN = CONFIG_FEATURE_EDITING_MAX_LEN < 0x7ff0
@@ -92,7 +118,7 @@ struct lineedit_statics {
 
         unsigned cursor;
         unsigned command_len;
-        char *command_ps;
+        CHAR_T *command_ps;
 
         const char *cmdedit_prompt;
 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
@@ -111,9 +137,9 @@ struct lineedit_statics {
 
 #if ENABLE_FEATURE_EDITING_VI
 #define DELBUFSIZ 128
-        char *delptr;
+        CHAR_T *delptr;
         smallint newdelflag;     /* whether delbuf should be reused yet */
-        char delbuf[DELBUFSIZ];  /* a place to store deleted characters */
+        CHAR_T delbuf[DELBUFSIZ];  /* a place to store deleted characters */
 #endif
 
         /* Formerly these were big buffers on stack: */
@@ -172,6 +198,49 @@ static void deinit_S(void)
 #define DEINIT_S() deinit_S()
 
 
+#if ENABLE_FEATURE_ASSUME_UNICODE
+static size_t load_string(const char *src, int maxsize)
+{
+        ssize_t len = mbstowcs(command_ps, src, maxsize - 1);
+        if (len < 0)
+                len = 0;
+        command_ps[len] = L'\0';
+        return len;
+}
+static size_t save_string(char *dst, int maxsize)
+{
+        ssize_t len = wcstombs(dst, command_ps, maxsize - 1);
+        if (len < 0)
+                len = 0;
+        dst[len] = '\0';
+        return len;
+}
+/* I thought just fputwc(c, stdout) would work. But no... */
+static void BB_PUTCHAR(wchar_t c)
+{
+        char buf[MB_CUR_MAX + 1];
+        mbstate_t mbst = { 0 };
+        ssize_t len = wcrtomb(buf, c, &mbst);
+
+        if (len > 0) {
+                buf[len] = '\0';
+                fputs(buf, stdout);
+        }
+}
+#else
+static size_t load_string(const char *src, int maxsize)
+{
+        safe_strncpy(command_ps, src, maxsize);
+        return strlen(command_ps);
+}
+static void save_string(char *dst, int maxsize)
+{
+        safe_strncpy(dst, command_ps, maxsize);
+}
+#define BB_PUTCHAR(c) bb_putchar(c)
+#endif
+
+
 /* Put 'command_ps[cursor]', cursor++.
  * Advance cursor on screen. If we reached right margin, scroll text up
  * and remove terminal margin effect by printing 'next_char' */
@@ -183,15 +252,15 @@ static void cmdedit_set_out_char(void)
 static void cmdedit_set_out_char(int next_char)
 #endif
 {
-        int c = (unsigned char)command_ps[cursor];
+        CHAR_T c = command_ps[cursor];
 
-        if (c == '\0') {
+        if (c == BB_NUL) {
                 /* erase character after end of input string */
                 c = ' ';
         }
 #if ENABLE_FEATURE_NONPRINTABLE_INVERSE_PUT
         /* Display non-printable characters in reverse */
-        if (!Isprint(c)) {
+        if (!BB_isprint(c)) {
                 if (c >= 128)
                         c -= 128;
                 if (c < ' ')
@@ -202,7 +271,7 @@ static void cmdedit_set_out_char(int next_char)
         } else
 #endif
         {
-                bb_putchar(c);
+                BB_PUTCHAR(c);
         }
         if (++cmdedit_x >= cmdedit_termw) {
                 /* terminal is scrolled down */
@@ -224,7 +293,7 @@ static void cmdedit_set_out_char(int next_char)
                 bb_putchar('\b');
 #endif
         }
-// Huh? What if command_ps[cursor] == '\0' (we are at the end already?)
+// Huh? What if command_ps[cursor] == BB_NUL (we are at the end already?)
         cursor++;
 }
 
@@ -357,7 +426,8 @@ static void input_delete(int save)
         }
 #endif
 
-        overlapping_strcpy(command_ps + j, command_ps + j + 1);
+        memmove(command_ps + j, command_ps + j + 1,
+                        (command_len - j + 1) * sizeof(command_ps[0]));
         command_len--;
         input_end();                    /* rewrite new line */
         cmdedit_set_out_char(' ');      /* erase char */
@@ -374,8 +444,9 @@ static void put(void)
                 return;
         ocursor = cursor;
         /* open hole and then fill it */
-        memmove(command_ps + cursor + j, command_ps + cursor, command_len - cursor + 1);
-        strncpy(command_ps + cursor, delbuf, j);
+        memmove(command_ps + cursor + j, command_ps + cursor,
+                        (command_len - cursor + 1) * sizeof(command_ps[0]));
+        memcpy(command_ps + cursor, delbuf, j * sizeof(command_ps[0]));
         command_len += j;
         input_end();                    /* rewrite new line */
         input_backward(cursor - ocursor - j + 1); /* at end of new text */
@@ -857,10 +928,10 @@ static void input_tab(smallint *lastWasTab)
 
                 *lastWasTab = TRUE;             /* flop trigger */
 
-                /* Make a local copy of the string -- up
-                 * to the position of the cursor */
-                tmp = strncpy(matchBuf, command_ps, cursor);
-                tmp[cursor] = '\0';
+                /* Make a local copy of the string --
+                 * up to the position of the cursor */
+                save_string(matchBuf, cursor + 1);
+                tmp = matchBuf;
 
                 find_type = find_match(matchBuf, &recalc_pos);
 
@@ -930,6 +1001,8 @@ static void input_tab(smallint *lastWasTab)
                 /* have space to placed match? */
                 if ((len_found - strlen(matchBuf) + command_len) < MAX_LINELEN) {
                         /* before word for match   */
+//TODO:
+#if !ENABLE_FEATURE_ASSUME_UNICODE
                         command_ps[cursor - recalc_pos] = '\0';
                         /* save   tail line        */
                         strcpy(matchBuf, command_ps + cursor);
@@ -944,6 +1017,7 @@ static void input_tab(smallint *lastWasTab)
                         /* new len                         */
                         command_len = strlen(command_ps);
                         /* write out the matched command   */
+#endif
                         redraw(cmdedit_y, command_len - recalc_pos);
                 }
                 free(tmp);
@@ -978,10 +1052,19 @@ line_input_t* FAST_FUNC new_line_input_t(int flags)
 
 static void save_command_ps_at_cur_history(void)
 {
-        if (command_ps[0] != '\0') {
+        if (command_ps[0] != BB_NUL) {
                 int cur = state->cur_history;
                 free(state->history[cur]);
+
+#if ENABLE_FEATURE_ASSUME_UNICODE
+                {
+                        char tbuf[MAX_LINELEN];
+                        save_string(tbuf, sizeof(tbuf));
+                        state->history[cur] = xstrdup(tbuf);
+                }
+#else
                 state->history[cur] = xstrdup(command_ps);
+#endif
         }
 }
 
@@ -1199,93 +1282,105 @@ static void remember_in_history(char *str)
 
 #if ENABLE_FEATURE_EDITING_VI
 static void
-vi_Word_motion(char *command, int eat)
+vi_Word_motion(int eat)
 {
-        while (cursor < command_len && !isspace(command[cursor]))
+        CHAR_T *command = command_ps;
+
+        while (cursor < command_len && !BB_isspace(command[cursor]))
                 input_forward();
-        if (eat) while (cursor < command_len && isspace(command[cursor]))
+        if (eat) while (cursor < command_len && BB_isspace(command[cursor]))
                 input_forward();
 }
 
 static void
-vi_word_motion(char *command, int eat)
+vi_word_motion(int eat)
 {
-        if (isalnum(command[cursor]) || command[cursor] == '_') {
+        CHAR_T *command = command_ps;
+
+        if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
                 while (cursor < command_len
-                 && (isalnum(command[cursor+1]) || command[cursor+1] == '_'))
+                 && (BB_isalnum(command[cursor+1]) || command[cursor+1] == '_'))
                         input_forward();
-        } else if (ispunct(command[cursor])) {
-                while (cursor < command_len && ispunct(command[cursor+1]))
+        } else if (BB_ispunct(command[cursor])) {
+                while (cursor < command_len && BB_ispunct(command[cursor+1]))
                         input_forward();
         }
 
         if (cursor < command_len)
                 input_forward();
 
-        if (eat && cursor < command_len && isspace(command[cursor]))
-                while (cursor < command_len && isspace(command[cursor]))
+        if (eat && cursor < command_len && BB_isspace(command[cursor]))
+                while (cursor < command_len && BB_isspace(command[cursor]))
                         input_forward();
 }
 
 static void
-vi_End_motion(char *command)
+vi_End_motion(void)
 {
+        CHAR_T *command = command_ps;
+
         input_forward();
-        while (cursor < command_len && isspace(command[cursor]))
+        while (cursor < command_len && BB_isspace(command[cursor]))
                 input_forward();
-        while (cursor < command_len-1 && !isspace(command[cursor+1]))
+        while (cursor < command_len-1 && !BB_isspace(command[cursor+1]))
                 input_forward();
 }
 
 static void
-vi_end_motion(char *command)
+vi_end_motion(void)
 {
+        CHAR_T *command = command_ps;
+
         if (cursor >= command_len-1)
                 return;
         input_forward();
-        while (cursor < command_len-1 && isspace(command[cursor]))
+        while (cursor < command_len-1 && BB_isspace(command[cursor]))
                 input_forward();
         if (cursor >= command_len-1)
                 return;
-        if (isalnum(command[cursor]) || command[cursor] == '_') {
+        if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
                 while (cursor < command_len-1
-                 && (isalnum(command[cursor+1]) || command[cursor+1] == '_')
+                 && (BB_isalnum(command[cursor+1]) || command[cursor+1] == '_')
                 ) {
                         input_forward();
                 }
-        } else if (ispunct(command[cursor])) {
-                while (cursor < command_len-1 && ispunct(command[cursor+1]))
+        } else if (BB_ispunct(command[cursor])) {
+                while (cursor < command_len-1 && BB_ispunct(command[cursor+1]))
                         input_forward();
         }
 }
 
 static void
-vi_Back_motion(char *command)
+vi_Back_motion(void)
 {
-        while (cursor > 0 && isspace(command[cursor-1]))
+        CHAR_T *command = command_ps;
+
+        while (cursor > 0 && BB_isspace(command[cursor-1]))
                 input_backward(1);
-        while (cursor > 0 && !isspace(command[cursor-1]))
+        while (cursor > 0 && !BB_isspace(command[cursor-1]))
                 input_backward(1);
 }
 
 static void
-vi_back_motion(char *command)
+vi_back_motion(void)
 {
+        CHAR_T *command = command_ps;
+
         if (cursor <= 0)
                 return;
         input_backward(1);
-        while (cursor > 0 && isspace(command[cursor]))
+        while (cursor > 0 && BB_isspace(command[cursor]))
                 input_backward(1);
         if (cursor <= 0)
                 return;
-        if (isalnum(command[cursor]) || command[cursor] == '_') {
+        if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
                 while (cursor > 0
-                 && (isalnum(command[cursor-1]) || command[cursor-1] == '_')
+                 && (BB_isalnum(command[cursor-1]) || command[cursor-1] == '_')
                 ) {
                         input_backward(1);
                 }
-        } else if (ispunct(command[cursor])) {
-                while (cursor > 0 && ispunct(command[cursor-1]))
+        } else if (BB_ispunct(command[cursor])) {
+                while (cursor > 0 && BB_ispunct(command[cursor-1]))
                         input_backward(1);
         }
 }
@@ -1446,6 +1541,11 @@ static int lineedit_read_key(char *read_key_buffer)
 {
         int64_t ic;
         struct pollfd pfd;
+        int delay = -1;
+#if ENABLE_FEATURE_ASSUME_UNICODE
+        char unicode_buf[MB_CUR_MAX + 1];
+        int unicode_idx = 0;
+#endif
 
         pfd.fd = STDIN_FILENO;
         pfd.events = POLLIN;
@@ -1455,7 +1555,7 @@ static int lineedit_read_key(char *read_key_buffer)
                         /* Wait for input. Can't just call read_key,
                          * it returns at once if stdin
                          * is in non-blocking mode. */
-                        safe_poll(&pfd, 1, -1);
+                        safe_poll(&pfd, 1, delay);
                 }
                 /* Note: read_key sets errno to 0 on success: */
                 ic = read_key(STDIN_FILENO, read_key_buffer);
@@ -1472,20 +1572,27 @@ static int lineedit_read_key(char *read_key_buffer)
                         }
                         goto poll_again;
                 }
+
+#if ENABLE_FEATURE_ASSUME_UNICODE
+                {
+                        wchar_t wc;
+
+                        if ((int32_t)ic < 0) /* KEYCODE_xxx */
+                                return ic;
+                        unicode_buf[unicode_idx++] = ic;
+                        unicode_buf[unicode_idx] = '\0';
+                        if (mbstowcs(&wc, unicode_buf, 1) < 1 && unicode_idx < MB_CUR_MAX) {
+                                delay = 50;
+                                goto poll_again;
+                        }
+                        ic = wc;
+                }
+#endif
         } while (errno == EAGAIN);
+
         return ic;
 }
 
-/*
- * The emacs and vi modes share much of the code in the big
- * command loop.  Commands entered when in vi's command mode (aka
- * "escape mode") get an extra bit added to distinguish them --
- * this keeps them from being self-inserted.  This clutters the
- * big switch a bit, but keeps all the code in one place.
- */
-
-#define VI_CMDMODE_BIT 0x100
-
 /* leave out the "vi-mode"-only case labels if vi editing isn't
  * configured. */
 #define vi_case(caselabel) IF_FEATURE_EDITING(case caselabel)
@@ -1505,7 +1612,6 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 #if ENABLE_FEATURE_TAB_COMPLETION
         smallint lastWasTab = FALSE;
 #endif
-        int ic;
         smallint break_out = 0;
 #if ENABLE_FEATURE_EDITING_VI
         smallint vi_cmdmode = 0;
@@ -1547,8 +1653,13 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
         /* prepare before init handlers */
         cmdedit_y = 0;  /* quasireal y, not true if line > xt*yt */
         command_len = 0;
+#if ENABLE_FEATURE_ASSUME_UNICODE
+        command_ps = xzalloc(maxsize * sizeof(command_ps[0]));
+#else
         command_ps = command;
         command[0] = '\0';
+#endif
+#define command command_must_not_be_used
 
         new_settings = initial_settings;
         new_settings.c_lflag &= ~ICANON;        /* unbuffered input */
@@ -1580,8 +1691,8 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 #endif
 
 #if 0
-        for (ic = 0; ic <= MAX_HISTORY; ic++)
-                bb_error_msg("history[%d]:'%s'", ic, state->history[ic]);
+        for (i = 0; i <= MAX_HISTORY; i++)
+                bb_error_msg("history[%d]:'%s'", i, state->history[i]);
         bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
 #endif
 
@@ -1590,6 +1701,20 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 
         read_key_buffer[0] = 0;
         while (1) {
+                /*
+                 * The emacs and vi modes share much of the code in the big
+                 * command loop.  Commands entered when in vi's command mode
+                 * (aka "escape mode") get an extra bit added to distinguish
+                 * them - this keeps them from being self-inserted. This
+                 * clutters the big switch a bit, but keeps all the code
+                 * in one place.
+                 */
+                enum {
+                        VI_CMDMODE_BIT = 0x40000000,
+                        /* 0x80000000 bit flags KEYCODE_xxx */
+                };
+                int32_t ic;
+
                 fflush(NULL);
                 ic = lineedit_read_key(read_key_buffer);
 
@@ -1667,7 +1792,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 #endif
                 case CTRL('K'):
                         /* Control-k -- clear to end of line */
-                        command[cursor] = 0;
+                        command_ps[cursor] = BB_NUL;
                         command_len = cursor;
                         printf("\033[J");
                         break;
@@ -1697,17 +1822,18 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                 vi_case(CTRL('U')|VI_CMDMODE_BIT:)
                         /* Control-U -- Clear line before cursor */
                         if (cursor) {
-                                overlapping_strcpy(command, command + cursor);
                                 command_len -= cursor;
+                                memmove(command_ps, command_ps + cursor,
+                                        (command_len + 1) * sizeof(command_ps[0]));
                                 redraw(cmdedit_y, command_len);
                         }
                         break;
                 case CTRL('W'):
                 vi_case(CTRL('W')|VI_CMDMODE_BIT:)
                         /* Control-W -- Remove the last word */
-                        while (cursor > 0 && isspace(command[cursor-1]))
+                        while (cursor > 0 && BB_isspace(command_ps[cursor-1]))
                                 input_backspace();
-                        while (cursor > 0 && !isspace(command[cursor-1]))
+                        while (cursor > 0 && !BB_isspace(command_ps[cursor-1]))
                                 input_backspace();
                         break;
 
@@ -1737,22 +1863,22 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                         }
                         break;
                 case 'W'|VI_CMDMODE_BIT:
-                        vi_Word_motion(command, 1);
+                        vi_Word_motion(1);
                         break;
                 case 'w'|VI_CMDMODE_BIT:
-                        vi_word_motion(command, 1);
+                        vi_word_motion(1);
                         break;
                 case 'E'|VI_CMDMODE_BIT:
-                        vi_End_motion(command);
+                        vi_End_motion();
                         break;
                 case 'e'|VI_CMDMODE_BIT:
-                        vi_end_motion(command);
+                        vi_end_motion();
                         break;
                 case 'B'|VI_CMDMODE_BIT:
-                        vi_Back_motion(command);
+                        vi_Back_motion();
                         break;
                 case 'b'|VI_CMDMODE_BIT:
-                        vi_back_motion(command);
+                        vi_back_motion();
                         break;
                 case 'C'|VI_CMDMODE_BIT:
                         vi_cmdmode = 0;
@@ -1787,17 +1913,17 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                         case 'E':
                                 switch (ic) {
                                 case 'w':   /* "dw", "cw" */
-                                        vi_word_motion(command, vi_cmdmode);
+                                        vi_word_motion(vi_cmdmode);
                                         break;
                                 case 'W':   /* 'dW', 'cW' */
-                                        vi_Word_motion(command, vi_cmdmode);
+                                        vi_Word_motion(vi_cmdmode);
                                         break;
                                 case 'e':   /* 'de', 'ce' */
-                                        vi_end_motion(command);
+                                        vi_end_motion();
                                         input_forward();
                                         break;
                                 case 'E':   /* 'dE', 'cE' */
-                                        vi_End_motion(command);
+                                        vi_End_motion();
                                         input_forward();
                                         break;
                                 }
@@ -1809,9 +1935,9 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                         case 'b':  /* "db", "cb" */
                         case 'B':  /* implemented as B */
                                 if (ic == 'b')
-                                        vi_back_motion(command);
+                                        vi_back_motion();
                                 else
-                                        vi_Back_motion(command);
+                                        vi_Back_motion();
                                 while (sc-- > cursor)
                                         input_delete(1);
                                 break;
@@ -1839,7 +1965,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                         if (ic < ' ' || ic > 255) {
                                 beep();
                         } else {
-                                command[cursor] = ic;
+                                command_ps[cursor] = ic;
                                 bb_putchar(ic);
                                 bb_putchar('\b');
                         }
@@ -1865,7 +1991,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
  rewrite_line:
                         /* Rewrite the line with the selected history item */
                         /* change command */
-                        command_len = strlen(strcpy(command, state->history[state->cur_history] ? : ""));
+                        command_len = load_string(state->history[state->cur_history] ? : "", maxsize);
                         /* redraw and go to eol (bol, in vi) */
                         redraw(cmdedit_y, (state->flags & VI_MODE) ? 9999 : 0);
                         break;
@@ -1896,7 +2022,10 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 //                                      break;
 //                              }
 //                      }
-                        if (ic < ' ' || ic > 255) {
+                        if (ic < ' '
+                         || (!ENABLE_FEATURE_ASSUME_UNICODE && ic >= 256)
+                         || (ENABLE_FEATURE_ASSUME_UNICODE && ic >= VI_CMDMODE_BIT)
+                        ) {
                                 /* If VI_CMDMODE_BIT is set, ic is >= 256
                                  * and command mode ignores unexpected chars.
                                  * Otherwise, we are here if ic is a
@@ -1913,15 +2042,16 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                         command_len++;
                         if (cursor == (command_len - 1)) {
                                 /* We are at the end, append */
-                                command[cursor] = ic;
-                                command[cursor + 1] = '\0';
+                                command_ps[cursor] = ic;
+                                command_ps[cursor + 1] = BB_NUL;
                                 cmdedit_set_out_char(' ');
                         } else {
                                 /* In the middle, insert */
                                 int sc = cursor;
 
-                                memmove(command + sc + 1, command + sc, command_len - sc);
-                                command[sc] = ic;
+                                memmove(command_ps + sc + 1, command_ps + sc,
+                                        (command_len - sc) * sizeof(command_ps[0]));
+                                command_ps[sc] = ic;
                                 sc++;
                                 /* rewrite from cursor */
                                 input_end();
@@ -1941,6 +2071,14 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 #endif
         } /* while (1) */
 
+/* Stop bug catching using "command_must_not_be_used" trick */
+#undef command
+
+#if ENABLE_FEATURE_ASSUME_UNICODE
+        command_len = save_string(command, maxsize - 1);
+        free(command_ps);
+#endif
+
         if (command_len > 0)
                 remember_in_history(command);
 
@@ -1976,7 +2114,7 @@ int FAST_FUNC read_line_input(const char* prompt, char* command, int maxsize)
         return strlen(command);
 }
 
-#endif  /* FEATURE_COMMAND_EDITING */
+#endif  /* FEATURE_EDITING */
 
 
 /*