lineedit: add support for history saving on exit
[oweals/busybox.git] / libbb / lineedit.c
index ff5d2840897a33e46338aa6842b3e389e98ffafb..0786f9ae6bd7c0ab676b67339c2f40b469cd3ace 100644 (file)
  */
 #include "libbb.h"
 #include "unicode.h"
+#ifndef _POSIX_VDISABLE
+# define _POSIX_VDISABLE '\0'
+#endif
+
 
 #ifdef TEST
 # define ENABLE_FEATURE_EDITING 0
@@ -94,8 +98,10 @@ static bool BB_ispunct(CHAR_T c) { return ((unsigned)c < 256 && ispunct(c)); }
 #endif
 
 
-#define SEQ_CLEAR_TILL_END_OF_SCREEN "\033[J"
-//#define SEQ_CLEAR_TILL_END_OF_LINE   "\033[K"
+#define ESC "\033"
+
+#define SEQ_CLEAR_TILL_END_OF_SCREEN  ESC"[J"
+//#define SEQ_CLEAR_TILL_END_OF_LINE  ESC"[K"
 
 
 enum {
@@ -150,11 +156,6 @@ struct lineedit_statics {
 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
        smallint sent_ESC_br6n;
 #endif
-
-       /* Formerly these were big buffers on stack: */
-#if ENABLE_FEATURE_TAB_COMPLETION
-       char input_tab__matchBuf[MAX_LINELEN];
-#endif
 };
 
 /* See lineedit_ptr_hack.c */
@@ -187,6 +188,7 @@ extern struct lineedit_statics *const lineedit_ptr_to_statics;
        IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines = 1;) \
        IF_USERNAME_OR_HOMEDIR(home_pwd_buf = (char*)null_str;) \
 } while (0)
+
 static void deinit_S(void)
 {
 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
@@ -205,67 +207,87 @@ static void deinit_S(void)
 
 
 #if ENABLE_UNICODE_SUPPORT
-static size_t load_string(const char *src, int maxsize)
+static size_t load_string(const char *src)
 {
-       ssize_t len = mbstowcs(command_ps, src, maxsize - 1);
-       if (len < 0)
-               len = 0;
-       command_ps[len] = BB_NUL;
-       return len;
+       if (unicode_status == UNICODE_ON) {
+               ssize_t len = mbstowcs(command_ps, src, S.maxsize - 1);
+               if (len < 0)
+                       len = 0;
+               command_ps[len] = BB_NUL;
+               return len;
+       } else {
+               unsigned i = 0;
+               while (src[i] && i < S.maxsize - 1) {
+                       command_ps[i] = src[i];
+                       i++;
+               }
+               command_ps[i] = BB_NUL;
+               return i;
+       }
 }
 static unsigned save_string(char *dst, unsigned maxsize)
 {
+       if (unicode_status == UNICODE_ON) {
 # if !ENABLE_UNICODE_PRESERVE_BROKEN
-       ssize_t len = wcstombs(dst, command_ps, maxsize - 1);
-       if (len < 0)
-               len = 0;
-       dst[len] = '\0';
-       return len;
+               ssize_t len = wcstombs(dst, command_ps, maxsize - 1);
+               if (len < 0)
+                       len = 0;
+               dst[len] = '\0';
+               return len;
 # else
-       unsigned dstpos = 0;
-       unsigned srcpos = 0;
+               unsigned dstpos = 0;
+               unsigned srcpos = 0;
 
-       maxsize--;
-       while (dstpos < maxsize) {
-               wchar_t wc;
-               int n = srcpos;
+               maxsize--;
+               while (dstpos < maxsize) {
+                       wchar_t wc;
+                       int n = srcpos;
 
-               /* Convert up to 1st invalid byte (or up to end) */
-               while ((wc = command_ps[srcpos]) != BB_NUL
-                   && !unicode_is_raw_byte(wc)
-               ) {
+                       /* Convert up to 1st invalid byte (or up to end) */
+                       while ((wc = command_ps[srcpos]) != BB_NUL
+                           && !unicode_is_raw_byte(wc)
+                       ) {
+                               srcpos++;
+                       }
+                       command_ps[srcpos] = BB_NUL;
+                       n = wcstombs(dst + dstpos, command_ps + n, maxsize - dstpos);
+                       if (n < 0) /* should not happen */
+                               break;
+                       dstpos += n;
+                       if (wc == BB_NUL) /* usually is */
+                               break;
+
+                       /* We do have invalid byte here! */
+                       command_ps[srcpos] = wc; /* restore it */
                        srcpos++;
+                       if (dstpos == maxsize)
+                               break;
+                       dst[dstpos++] = (char) wc;
                }
-               command_ps[srcpos] = BB_NUL;
-               n = wcstombs(dst + dstpos, command_ps + n, maxsize - dstpos);
-               if (n < 0) /* should not happen */
-                       break;
-               dstpos += n;
-               if (wc == BB_NUL) /* usually is */
-                       break;
-
-               /* We do have invalid byte here! */
-               command_ps[srcpos] = wc; /* restore it */
-               srcpos++;
-               if (dstpos == maxsize)
-                       break;
-               dst[dstpos++] = (char) wc;
-       }
-       dst[dstpos] = '\0';
-       return dstpos;
+               dst[dstpos] = '\0';
+               return dstpos;
 # endif
+       } else {
+               unsigned i = 0;
+               while ((dst[i] = command_ps[i]) != 0)
+                       i++;
+               return i;
+       }
 }
 /* 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;
-
-       len = wcrtomb(buf, c, &mbst);
-       if (len > 0) {
-               buf[len] = '\0';
-               fputs(buf, stdout);
+       if (unicode_status == UNICODE_ON) {
+               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 {
+               /* In this case, c is always one byte */
+               putchar(c);
        }
 }
 # if ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS
@@ -300,9 +322,9 @@ static wchar_t adjust_width_and_validate_wc(wchar_t wc)
        return wc;
 }
 #else /* !UNICODE */
-static size_t load_string(const char *src, int maxsize)
+static size_t load_string(const char *src)
 {
-       safe_strncpy(command_ps, src, maxsize);
+       safe_strncpy(command_ps, src, S.maxsize);
        return strlen(command_ps);
 }
 # if ENABLE_FEATURE_TAB_COMPLETION
@@ -451,7 +473,7 @@ static void input_backward(unsigned num)
                        } while (--num);
                        return;
                }
-               printf("\033[%uD", num);
+               printf(ESC"[%uD", num);
                return;
        }
 
@@ -476,7 +498,7 @@ static void input_backward(unsigned num)
                 */
                unsigned sv_cursor;
                /* go to 1st column; go up to first line */
-               printf("\r" "\033[%uA", cmdedit_y);
+               printf("\r" ESC"[%uA", cmdedit_y);
                cmdedit_y = 0;
                sv_cursor = cursor;
                put_prompt(); /* sets cursor to 0 */
@@ -493,12 +515,12 @@ static void input_backward(unsigned num)
                cmdedit_x = (width * cmdedit_y - num) % width;
                cmdedit_y -= lines_up;
                /* go to 1st column; go up */
-               printf("\r" "\033[%uA", lines_up);
+               printf("\r" ESC"[%uA", lines_up);
                /* go to correct column.
                 * xterm, konsole, Linux VT interpret 0 as 1 below! wow.
                 * need to *make sure* we skip it if cmdedit_x == 0 */
                if (cmdedit_x)
-                       printf("\033[%uC", cmdedit_x);
+                       printf(ESC"[%uC", cmdedit_x);
        }
 }
 
@@ -506,7 +528,7 @@ static void input_backward(unsigned num)
 static void redraw(int y, int back_cursor)
 {
        if (y > 0) /* up y lines */
-               printf("\033[%uA", y);
+               printf(ESC"[%uA", y);
        bb_putchar('\r');
        put_prompt();
        put_till_end_and_adv_cursor();
@@ -587,6 +609,12 @@ static void input_forward(void)
 
 #if ENABLE_FEATURE_TAB_COMPLETION
 
+//FIXME:
+//needs to be more clever: currently it thinks that "foo\ b<TAB>
+//matches the file named "foo bar", which is untrue.
+//Also, perhaps "foo b<TAB> needs to complete to "foo bar" <cursor>,
+//not "foo bar <cursor>...
+
 static void free_tab_completion_data(void)
 {
        if (matches) {
@@ -604,7 +632,7 @@ static void add_match(char *matched)
        num_matches++;
 }
 
-#if ENABLE_FEATURE_USERNAME_COMPLETION
+# if ENABLE_FEATURE_USERNAME_COMPLETION
 /* Replace "~user/..." with "/homedir/...".
  * The parameter is malloced, free it or return it
  * unchanged if no user is matched.
@@ -660,7 +688,7 @@ static NOINLINE unsigned complete_username(const char *ud)
 
        return 1 + userlen;
 }
-#endif  /* FEATURE_USERNAME_COMPLETION */
+# endif  /* FEATURE_USERNAME_COMPLETION */
 
 enum {
        FIND_EXE_ONLY = 0,
@@ -737,10 +765,10 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
                pfind++;
                /* dirbuf = ".../.../.../" */
                dirbuf = xstrndup(command, pfind - command);
-#if ENABLE_FEATURE_USERNAME_COMPLETION
+# if ENABLE_FEATURE_USERNAME_COMPLETION
                if (dirbuf[0] == '~')   /* ~/... or ~user/... */
                        dirbuf = username_path_completion(dirbuf);
-#endif
+# endif
                path1[0] = dirbuf;
        }
        pf_len = strlen(pfind);
@@ -756,6 +784,7 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
                        continue; /* don't print an error */
 
                while ((next = readdir(dir)) != NULL) {
+                       unsigned len;
                        const char *name_found = next->d_name;
 
                        /* .../<tab>: bash 3.2.0 shows dotfiles, but not . and .. */
@@ -772,18 +801,15 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
                        if (stat(found, &st) && lstat(found, &st))
                                goto cont; /* hmm, remove in progress? */
 
-                       /* save only name if we scan PATH */
-                       if (paths[i] != dirbuf)
-                               strcpy(found, name_found);
+                       /* Save only name */
+                       len = strlen(name_found);
+                       found = xrealloc(found, len + 2); /* +2: for slash and NUL */
+                       strcpy(found, name_found);
 
                        if (S_ISDIR(st.st_mode)) {
-                               unsigned len1 = strlen(found);
-                               /* name is a directory */
-                               if (found[len1-1] != '/') {
-                                       found = xrealloc(found, len1 + 2);
-                                       found[len1] = '/';
-                                       found[len1 + 1] = '\0';
-                               }
+                               /* name is a directory, add slash */
+                               found[len] = '/';
+                               found[len + 1] = '\0';
                        } else {
                                /* skip files if looking for dirs only (example: cd) */
                                if (type == FIND_DIR_ONLY)
@@ -801,26 +827,24 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
        if (paths != path1) {
                free(paths[0]); /* allocated memory is only in first member */
                free(paths);
-       } else if (dirbuf) {
-               pf_len += strlen(dirbuf);
-               free(dirbuf);
        }
+       free(dirbuf);
 
        return pf_len;
 }
 
 /* build_match_prefix:
- * On entry, matchBuf contains everything up to cursor at the moment <tab>
+ * On entry, match_buf contains everything up to cursor at the moment <tab>
  * was pressed. This function looks at it, figures out what part of it
  * constitutes the command/file/directory prefix to use for completion,
- * and rewrites matchBuf to contain only that part.
+ * and rewrites match_buf to contain only that part.
  */
+#define dbg_bmp 0
 /* Helpers: */
 /* QUOT is used on elements of int_buf[], which are bytes,
  * not Unicode chars. Therefore it works correctly even in Unicode mode.
  */
 #define QUOT (UCHAR_MAX+1)
-#define dbg_bmp 0
 static void remove_chunk(int16_t *int_buf, int beg, int end)
 {
        /* beg must be <= end */
@@ -837,25 +861,29 @@ static void remove_chunk(int16_t *int_buf, int beg, int end)
                bb_putchar('\n');
        }
 }
-static NOINLINE int build_match_prefix(char *matchBuf)
+/* Caller ensures that match_buf points to a malloced buffer
+ * big enough to hold strlen(match_buf)*2 + 2
+ */
+static NOINLINE int build_match_prefix(char *match_buf)
 {
        int i, j;
        int command_mode;
-       int16_t *int_buf;
+       int16_t *int_buf = (int16_t*)match_buf;
 
-       if (dbg_bmp) printf("\n%s\n", matchBuf);
+       if (dbg_bmp) printf("\n%s\n", match_buf);
 
-       int_buf = xmalloc(sizeof(int_buf[0]) * (strlen(matchBuf) + 1));
-       i = 0;
-       while ((int_buf[i] = (unsigned char)matchBuf[i]) != '\0')
-               i++;
+       /* Copy in reverse order, since they overlap */
+       i = strlen(match_buf);
+       do {
+               int_buf[i] = (unsigned char)match_buf[i];
+               i--;
+       } while (i >= 0);
 
        /* Mark every \c as "quoted c" */
-       for (i = j = 0; matchBuf[i]; i++, j++) {
-               if (matchBuf[i] == '\\') {
-                       remove_chunk(int_buf, j, j + 1);
-                       int_buf[j] |= QUOT;
-                       i++;
+       for (i = 0; int_buf[i]; i++) {
+               if (int_buf[i] == '\\') {
+                       remove_chunk(int_buf, i, i + 1);
+                       int_buf[i] |= QUOT;
                }
        }
        /* Quote-mark "chars" and 'chars', drop delimiters */
@@ -964,13 +992,12 @@ static NOINLINE int build_match_prefix(char *matchBuf)
                }
        }
 
-       /* Store only match prefix */
+       /* Convert back to string of _chars_ */
        i = 0;
-       while ((matchBuf[i] = int_buf[i]) != '\0')
+       while ((match_buf[i] = int_buf[i]) != '\0')
                i++;
-       free(int_buf);
 
-       if (dbg_bmp) printf("final matchBuf:'%s'\n", matchBuf);
+       if (dbg_bmp) printf("final match_buf:'%s'\n", match_buf);
 
        return command_mode;
 }
@@ -1019,13 +1046,18 @@ static void showfiles(void)
        }
 }
 
-static char *add_quote_for_spec_chars(char *found)
+static const char *is_special_char(char c)
+{
+       return strchr(" `\"#$%^&*()=+{}[]:;'|\\<>", c);
+}
+
+static char *quote_special_chars(char *found)
 {
        int l = 0;
        char *s = xzalloc((strlen(found) + 1) * 2);
 
        while (*found) {
-               if (strchr(" `\"#$%^&*()=+{}[]:;'|\\<>", *found))
+               if (is_special_char(*found))
                        s[l++] = '\\';
                s[l++] = *found++;
        }
@@ -1037,16 +1069,15 @@ static char *add_quote_for_spec_chars(char *found)
 static NOINLINE void input_tab(smallint *lastWasTab)
 {
        char *chosen_match;
+       char *match_buf;
        size_t len_found;
-/*     char matchBuf[MAX_LINELEN]; */
-#define matchBuf (S.input_tab__matchBuf)
        /* Length of string used for matching */
        unsigned match_pfx_len = match_pfx_len;
        int find_type;
-#if ENABLE_UNICODE_SUPPORT
+# if ENABLE_UNICODE_SUPPORT
        /* cursor pos in command converted to multibyte form */
        int cursor_mb;
-#endif
+# endif
        if (!(state->flags & TAB_COMPLETION))
                return;
 
@@ -1065,39 +1096,55 @@ static NOINLINE void input_tab(smallint *lastWasTab)
        }
 
        *lastWasTab = 1;
+       chosen_match = NULL;
 
-       /* Make a local copy of the string --
-        * up to the position of the cursor */
-#if !ENABLE_UNICODE_SUPPORT
-       save_string(matchBuf, cursor + 1);
-#else
+       /* Make a local copy of the string up to the position of the cursor.
+        * build_match_prefix will expand it into int16_t's, need to allocate
+        * twice as much as the string_len+1.
+        * (we then also (ab)use this extra space later - see (**))
+        */
+       match_buf = xmalloc(MAX_LINELEN * sizeof(int16_t));
+# if !ENABLE_UNICODE_SUPPORT
+       save_string(match_buf, cursor + 1); /* +1 for NUL */
+# else
        {
                CHAR_T wc = command_ps[cursor];
                command_ps[cursor] = BB_NUL;
-               save_string(matchBuf, MAX_LINELEN);
+               save_string(match_buf, MAX_LINELEN);
                command_ps[cursor] = wc;
-               cursor_mb = strlen(matchBuf);
+               cursor_mb = strlen(match_buf);
        }
-#endif
-       find_type = build_match_prefix(matchBuf);
+# endif
+       find_type = build_match_prefix(match_buf);
 
        /* Free up any memory already allocated */
        free_tab_completion_data();
 
-#if ENABLE_FEATURE_USERNAME_COMPLETION
-       /* If the word starts with `~' and there is no slash in the word,
+# if ENABLE_FEATURE_USERNAME_COMPLETION
+       /* If the word starts with ~ and there is no slash in the word,
         * then try completing this word as a username. */
        if (state->flags & USERNAME_COMPLETION)
-               if (matchBuf[0] == '~' && strchr(matchBuf, '/') == NULL)
-                       match_pfx_len = complete_username(matchBuf);
-#endif
-       /* Try to match a command in $PATH, or a directory, or a file */
+               if (match_buf[0] == '~' && strchr(match_buf, '/') == NULL)
+                       match_pfx_len = complete_username(match_buf);
+# endif
+       /* If complete_username() did not match,
+        * try to match a command in $PATH, or a directory, or a file */
        if (!matches)
-               match_pfx_len = complete_cmd_dir_file(matchBuf, find_type);
+               match_pfx_len = complete_cmd_dir_file(match_buf, find_type);
+
+       /* Account for backslashes which will be inserted
+        * by quote_special_chars() later */
+       {
+               const char *e = match_buf + strlen(match_buf);
+               const char *s = e - match_pfx_len;
+               while (s < e)
+                       if (is_special_char(*s++))
+                               match_pfx_len++;
+       }
+
        /* Remove duplicates */
        if (matches) {
-               unsigned i;
-               unsigned n = 0;
+               unsigned i, n = 0;
                qsort_string_vector(matches, num_matches);
                for (i = 0; i < num_matches - 1; ++i) {
                        //if (matches[i] && matches[i+1]) { /* paranoia */
@@ -1112,12 +1159,13 @@ static NOINLINE void input_tab(smallint *lastWasTab)
                matches[n++] = matches[i];
                num_matches = n;
        }
+
        /* Did we find exactly one match? */
        if (num_matches != 1) { /* no */
                char *cp;
                beep();
                if (!matches)
-                       return; /* no matches at all */
+                       goto ret; /* no matches at all */
                /* Find common prefix */
                chosen_match = xstrdup(matches[0]);
                for (cp = chosen_match; *cp; cp++) {
@@ -1130,11 +1178,10 @@ static NOINLINE void input_tab(smallint *lastWasTab)
                }
  stop:
                if (cp == chosen_match) { /* have unique prefix? */
-                       free(chosen_match); /* no */
-                       return;
+                       goto ret; /* no */
                }
                *cp = '\0';
-               cp = add_quote_for_spec_chars(chosen_match);
+               cp = quote_special_chars(chosen_match);
                free(chosen_match);
                chosen_match = cp;
                len_found = strlen(chosen_match);
@@ -1142,7 +1189,7 @@ static NOINLINE void input_tab(smallint *lastWasTab)
                /* Next <tab> is not a double-tab */
                *lastWasTab = 0;
 
-               chosen_match = add_quote_for_spec_chars(matches[0]);
+               chosen_match = quote_special_chars(matches[0]);
                len_found = strlen(chosen_match);
                if (chosen_match[len_found-1] != '/') {
                        chosen_match[len_found] = ' ';
@@ -1150,7 +1197,7 @@ static NOINLINE void input_tab(smallint *lastWasTab)
                }
        }
 
-#if !ENABLE_UNICODE_SUPPORT
+# if !ENABLE_UNICODE_SUPPORT
        /* Have space to place the match? */
        /* The result consists of three parts with these lengths: */
        /* cursor + (len_found - match_pfx_len) + (command_len - cursor) */
@@ -1158,31 +1205,32 @@ static NOINLINE void input_tab(smallint *lastWasTab)
        if ((int)(len_found - match_pfx_len + command_len) < S.maxsize) {
                int pos;
                /* save tail */
-               strcpy(matchBuf, &command_ps[cursor]);
+               strcpy(match_buf, &command_ps[cursor]);
                /* add match and tail */
-               sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, matchBuf);
+               sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, match_buf);
                command_len = strlen(command_ps);
                /* new pos */
                pos = cursor + len_found - match_pfx_len;
                /* write out the matched command */
                redraw(cmdedit_y, command_len - pos);
        }
-#else
+# else
        {
-               char command[MAX_LINELEN];
-               int len = save_string(command, sizeof(command));
+               /* Use 2nd half of match_buf as scratch space - see (**) */
+               char *command = match_buf + MAX_LINELEN;
+               int len = save_string(command, MAX_LINELEN);
                /* Have space to place the match? */
                /* cursor_mb + (len_found - match_pfx_len) + (len - cursor_mb) */
                if ((int)(len_found - match_pfx_len + len) < MAX_LINELEN) {
                        int pos;
                        /* save tail */
-                       strcpy(matchBuf, &command[cursor_mb]);
+                       strcpy(match_buf, &command[cursor_mb]);
                        /* where do we want to have cursor after all? */
                        strcpy(&command[cursor_mb], chosen_match + match_pfx_len);
-                       len = load_string(command, S.maxsize);
+                       len = load_string(command);
                        /* add match and tail */
-                       sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, matchBuf);
-                       command_len = load_string(command, S.maxsize);
+                       sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, match_buf);
+                       command_len = load_string(command);
                        /* write out the matched command */
                        /* paranoia: load_string can return 0 on conv error,
                         * prevent passing pos = (0 - 12) to redraw */
@@ -1190,9 +1238,10 @@ static NOINLINE void input_tab(smallint *lastWasTab)
                        redraw(cmdedit_y, pos >= 0 ? pos : 0);
                }
        }
-#endif
+# endif
+ ret:
        free(chosen_match);
-#undef matchBuf
+       free(match_buf);
 }
 
 #endif  /* FEATURE_TAB_COMPLETION */
@@ -1202,12 +1251,26 @@ line_input_t* FAST_FUNC new_line_input_t(int flags)
 {
        line_input_t *n = xzalloc(sizeof(*n));
        n->flags = flags;
+       n->max_history = MAX_HISTORY;
        return n;
 }
 
 
 #if MAX_HISTORY > 0
 
+unsigned size_from_HISTFILESIZE(const char *hp)
+{
+       int size = MAX_HISTORY;
+       if (hp) {
+               size = atoi(hp);
+               if (size <= 0)
+                       return 1;
+               if (size > MAX_HISTORY)
+                       return MAX_HISTORY;
+       }
+       return size;
+}
+
 static void save_command_ps_at_cur_history(void)
 {
        if (command_ps[0] != BB_NUL) {
@@ -1288,7 +1351,9 @@ static void load_history(line_input_t *st_parm)
 
                /* fill temp_h[], retaining only last MAX_HISTORY lines */
                memset(temp_h, 0, sizeof(temp_h));
-               st_parm->cnt_history_in_file = idx = 0;
+               idx = 0;
+               if (!ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                       st_parm->cnt_history_in_file = 0;
                while ((line = xmalloc_fgetline(fp)) != NULL) {
                        if (line[0] == '\0') {
                                free(line);
@@ -1296,9 +1361,10 @@ static void load_history(line_input_t *st_parm)
                        }
                        free(temp_h[idx]);
                        temp_h[idx] = line;
-                       st_parm->cnt_history_in_file++;
+                       if (!ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                               st_parm->cnt_history_in_file++;
                        idx++;
-                       if (idx == MAX_HISTORY)
+                       if (idx == st_parm->max_history)
                                idx = 0;
                }
                fclose(fp);
@@ -1307,18 +1373,18 @@ static void load_history(line_input_t *st_parm)
                if (st_parm->cnt_history_in_file) {
                        while (temp_h[idx] == NULL) {
                                idx++;
-                               if (idx == MAX_HISTORY)
+                               if (idx == st_parm->max_history)
                                        idx = 0;
                        }
                }
 
                /* copy temp_h[] to st_parm->history[] */
-               for (i = 0; i < MAX_HISTORY;) {
+               for (i = 0; i < st_parm->max_history;) {
                        line = temp_h[idx];
                        if (!line)
                                break;
                        idx++;
-                       if (idx == MAX_HISTORY)
+                       if (idx == st_parm->max_history)
                                idx = 0;
                        line_len = strlen(line);
                        if (line_len >= MAX_LINELEN)
@@ -1326,16 +1392,67 @@ static void load_history(line_input_t *st_parm)
                        st_parm->history[i++] = line;
                }
                st_parm->cnt_history = i;
+               if (ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                       st_parm->cnt_history_in_file = i;
        }
 }
 
-/* state->flags is already checked to be nonzero */
+#  if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
+void save_history(line_input_t *st)
+{
+       FILE *fp;
+
+       if (!(st->flags & SAVE_HISTORY))
+               return;
+       if (!st->hist_file)
+               return;
+       if (st->cnt_history <= st->cnt_history_in_file)
+               return;
+
+       fp = fopen(st->hist_file, "a");
+       if (fp) {
+               int i, fd;
+               char *new_name;
+               line_input_t *st_temp;
+
+               for (i = st->cnt_history_in_file; i < st->cnt_history; i++)
+                       fprintf(fp, "%s\n", st->history[i]);
+               fclose(fp);
+
+               /* we may have concurrently written entries from others.
+                * load them */
+               st_temp = new_line_input_t(st->flags);
+               st_temp->hist_file = st->hist_file;
+               st_temp->max_history = st->max_history;
+               load_history(st_temp);
+
+               /* write out temp file and replace hist_file atomically */
+               new_name = xasprintf("%s.%u.new", st->hist_file, (int) getpid());
+               fd = open(new_name, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+               if (fd >= 0) {
+                       fp = xfdopen_for_write(fd);
+                       for (i = 0; i < st_temp->cnt_history; i++)
+                               fprintf(fp, "%s\n", st_temp->history[i]);
+                       fclose(fp);
+                       if (rename(new_name, st->hist_file) == 0)
+                               st->cnt_history_in_file = st_temp->cnt_history;
+               }
+               free(new_name);
+               free_line_input_t(st_temp);
+       }
+}
+#  else
 static void save_history(char *str)
 {
        int fd;
        int len, len2;
 
-       fd = open(state->hist_file, O_WRONLY | O_CREAT | O_APPEND, 0666);
+       if (!(state->flags & SAVE_HISTORY))
+               return;
+       if (!state->hist_file)
+               return;
+
+       fd = open(state->hist_file, O_WRONLY | O_CREAT | O_APPEND, 0600);
        if (fd < 0)
                return;
        xlseek(fd, 0, SEEK_END); /* paranoia */
@@ -1349,22 +1466,25 @@ static void save_history(char *str)
 
        /* did we write so much that history file needs trimming? */
        state->cnt_history_in_file++;
-       if (state->cnt_history_in_file > MAX_HISTORY * 4) {
-               FILE *fp;
+       if (state->cnt_history_in_file > state->max_history * 4) {
                char *new_name;
                line_input_t *st_temp;
-               int i;
 
                /* we may have concurrently written entries from others.
                 * load them */
                st_temp = new_line_input_t(state->flags);
                st_temp->hist_file = state->hist_file;
+               st_temp->max_history = state->max_history;
                load_history(st_temp);
 
                /* write out temp file and replace hist_file atomically */
                new_name = xasprintf("%s.%u.new", state->hist_file, (int) getpid());
-               fp = fopen_for_write(new_name);
-               if (fp) {
+               fd = open(new_name, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+               if (fd >= 0) {
+                       FILE *fp;
+                       int i;
+
+                       fp = xfdopen_for_write(fd);
                        for (i = 0; i < st_temp->cnt_history; i++)
                                fprintf(fp, "%s\n", st_temp->history[i]);
                        fclose(fp);
@@ -1375,6 +1495,7 @@ static void save_history(char *str)
                free_line_input_t(st_temp);
        }
 }
+#  endif
 # else
 #  define load_history(a) ((void)0)
 #  define save_history(a) ((void)0)
@@ -1393,25 +1514,26 @@ static void remember_in_history(char *str)
        if (i && strcmp(state->history[i-1], str) == 0)
                return;
 
-       free(state->history[MAX_HISTORY]); /* redundant, paranoia */
-       state->history[MAX_HISTORY] = NULL; /* redundant, paranoia */
+       free(state->history[state->max_history]); /* redundant, paranoia */
+       state->history[state->max_history] = NULL; /* redundant, paranoia */
 
        /* If history[] is full, remove the oldest command */
-       /* we need to keep history[MAX_HISTORY] empty, hence >=, not > */
-       if (i >= MAX_HISTORY) {
+       /* we need to keep history[state->max_history] empty, hence >=, not > */
+       if (i >= state->max_history) {
                free(state->history[0]);
-               for (i = 0; i < MAX_HISTORY-1; i++)
+               for (i = 0; i < state->max_history-1; i++)
                        state->history[i] = state->history[i+1];
-               /* i == MAX_HISTORY-1 */
+               /* i == state->max_history-1 */
+               if (ENABLE_FEATURE_EDITING_SAVE_ON_EXIT && state->cnt_history_in_file)
+                       state->cnt_history_in_file--;
        }
-       /* i <= MAX_HISTORY-1 */
+       /* i <= state->max_history-1 */
        state->history[i++] = xstrdup(str);
-       /* i <= MAX_HISTORY */
+       /* i <= state->max_history */
        state->cur_history = i;
        state->cnt_history = i;
-# if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
-       if ((state->flags & SAVE_HISTORY) && state->hist_file)
-               save_history(str);
+# if ENABLE_FEATURE_EDITING_SAVEHISTORY && !ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
+       save_history(str);
 # endif
        IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines++;)
 }
@@ -1618,7 +1740,7 @@ static void ask_terminal(void)
         * write(1, "~/srcdevel/bbox/fix/busybox.t4 # ", 33) = 33
         * poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout)  <-- no input exists
         * write(1, "\33[6n", 4) = 4  <-- send the ESC sequence, quick!
-        * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
+        * poll([{fd=0, events=POLLIN}], 1, -1) = 1 ([{fd=0, revents=POLLIN}])
         * read(0, "\n", 1)      = 1  <-- oh crap, user's input got in first
         */
        struct pollfd pfd;
@@ -1627,7 +1749,7 @@ static void ask_terminal(void)
        pfd.events = POLLIN;
        if (safe_poll(&pfd, 1, 0) == 0) {
                S.sent_ESC_br6n = 1;
-               fputs("\033" "[6n", stdout);
+               fputs(ESC"[6n", stdout);
                fflush_all(); /* make terminal see it ASAP! */
        }
 }
@@ -1776,17 +1898,17 @@ static void win_changed(int nsig)
 {
        int sv_errno = errno;
        unsigned width;
+
        get_terminal_width_height(0, &width, NULL);
-       cmdedit_setwidth(width, nsig /* - just a yes/no flag */);
-       if (nsig == SIGWINCH)
-               signal(SIGWINCH, win_changed); /* rearm ourself */
+//FIXME: cmdedit_setwidth() -> redraw() -> printf() -> KABOOM! (we are in signal handler!)
+       cmdedit_setwidth(width, /*redraw_flg:*/ nsig);
+
        errno = sv_errno;
 }
 
-static int lineedit_read_key(char *read_key_buffer)
+static int lineedit_read_key(char *read_key_buffer, int timeout)
 {
        int64_t ic;
-       int timeout = -1;
 #if ENABLE_UNICODE_SUPPORT
        char unicode_buf[MB_CUR_MAX + 1];
        int unicode_idx = 0;
@@ -1885,13 +2007,147 @@ static int isrtl_str(void)
 #undef CTRL
 #define CTRL(a) ((a) & ~0x40)
 
+enum {
+       VI_CMDMODE_BIT = 0x40000000,
+       /* 0x80000000 bit flags KEYCODE_xxx */
+};
+
+#if ENABLE_FEATURE_REVERSE_SEARCH
+/* Mimic readline Ctrl-R reverse history search.
+ * When invoked, it shows the following prompt:
+ * (reverse-i-search)'': user_input [cursor pos unchanged by Ctrl-R]
+ * and typing results in search being performed:
+ * (reverse-i-search)'tmp': cd /tmp [cursor under t in /tmp]
+ * Search is performed by looking at progressively older lines in history.
+ * Ctrl-R again searches for the next match in history.
+ * Backspace deletes last matched char.
+ * Control keys exit search and return to normal editing (at current history line).
+ */
+static int32_t reverse_i_search(void)
+{
+       char match_buf[128]; /* for user input */
+       char read_key_buffer[KEYCODE_BUFFER_SIZE];
+       const char *matched_history_line;
+       const char *saved_prompt;
+       int32_t ic;
+
+       matched_history_line = NULL;
+       read_key_buffer[0] = 0;
+       match_buf[0] = '\0';
+
+       /* Save and replace the prompt */
+       saved_prompt = cmdedit_prompt;
+       goto set_prompt;
+
+       while (1) {
+               int h;
+               unsigned match_buf_len = strlen(match_buf);
+
+               fflush_all();
+//FIXME: correct timeout?
+               ic = lineedit_read_key(read_key_buffer, -1);
+
+               switch (ic) {
+               case CTRL('R'): /* searching for the next match */
+                       break;
+
+               case '\b':
+               case '\x7f':
+                       /* Backspace */
+                       if (unicode_status == UNICODE_ON) {
+                               while (match_buf_len != 0) {
+                                       uint8_t c = match_buf[--match_buf_len];
+                                       if ((c & 0xc0) != 0x80) /* start of UTF-8 char? */
+                                               break; /* yes */
+                               }
+                       } else {
+                               if (match_buf_len != 0)
+                                       match_buf_len--;
+                       }
+                       match_buf[match_buf_len] = '\0';
+                       break;
+
+               default:
+                       if (ic < ' '
+                        || (!ENABLE_UNICODE_SUPPORT && ic >= 256)
+                        || (ENABLE_UNICODE_SUPPORT && ic >= VI_CMDMODE_BIT)
+                       ) {
+                               goto ret;
+                       }
+
+                       /* Append this char */
+#if ENABLE_UNICODE_SUPPORT
+                       if (unicode_status == UNICODE_ON) {
+                               mbstate_t mbstate = { 0 };
+                               char buf[MB_CUR_MAX + 1];
+                               int len = wcrtomb(buf, ic, &mbstate);
+                               if (len > 0) {
+                                       buf[len] = '\0';
+                                       if (match_buf_len + len < sizeof(match_buf))
+                                               strcpy(match_buf + match_buf_len, buf);
+                               }
+                       } else
+#endif
+                       if (match_buf_len < sizeof(match_buf) - 1) {
+                               match_buf[match_buf_len] = ic;
+                               match_buf[match_buf_len + 1] = '\0';
+                       }
+                       break;
+               } /* switch (ic) */
+
+               /* Search in history for match_buf */
+               h = state->cur_history;
+               if (ic == CTRL('R'))
+                       h--;
+               while (h >= 0) {
+                       if (state->history[h]) {
+                               char *match = strstr(state->history[h], match_buf);
+                               if (match) {
+                                       state->cur_history = h;
+                                       matched_history_line = state->history[h];
+                                       command_len = load_string(matched_history_line);
+                                       cursor = match - matched_history_line;
+//FIXME: cursor position for Unicode case
+
+                                       free((char*)cmdedit_prompt);
+ set_prompt:
+                                       cmdedit_prompt = xasprintf("(reverse-i-search)'%s': ", match_buf);
+                                       cmdedit_prmt_len = strlen(cmdedit_prompt);
+                                       goto do_redraw;
+                               }
+                       }
+                       h--;
+               }
+
+               /* Not found */
+               match_buf[match_buf_len] = '\0';
+               beep();
+               continue;
+
+ do_redraw:
+               redraw(cmdedit_y, command_len - cursor);
+       } /* while (1) */
+
+ ret:
+       if (matched_history_line)
+               command_len = load_string(matched_history_line);
+
+       free((char*)cmdedit_prompt);
+       cmdedit_prompt = saved_prompt;
+       cmdedit_prmt_len = strlen(cmdedit_prompt);
+       redraw(cmdedit_y, command_len - cursor);
+
+       return ic;
+}
+#endif
+
 /* maxsize must be >= 2.
  * Returns:
  * -1 on read errors or EOF, or on bare Ctrl-D,
  * 0  on ctrl-C (the line entered is still returned in 'command'),
  * >0 length of input string, including terminating '\n'
  */
-int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, line_input_t *st)
+int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *command, int maxsize, int timeout)
 {
        int len;
 #if ENABLE_FEATURE_TAB_COMPLETION
@@ -1928,7 +2184,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                maxsize = MAX_LINELEN;
        S.maxsize = maxsize;
 
-       /* With null flags, no other fields are ever used */
+       /* With zero flags, no other fields are ever used */
        state = st ? st : (line_input_t*) &const_int_0;
 #if MAX_HISTORY > 0
 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
@@ -1959,15 +2215,9 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
        new_settings.c_cc[VMIN] = 1;
        new_settings.c_cc[VTIME] = 0;
        /* Turn off CTRL-C, so we can trap it */
-#ifndef _POSIX_VDISABLE
-# define _POSIX_VDISABLE '\0'
-#endif
        new_settings.c_cc[VINTR] = _POSIX_VDISABLE;
        tcsetattr_stdin_TCSANOW(&new_settings);
 
-       /* Now initialize things */
-       previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
-       win_changed(0); /* do initial resizing */
 #if ENABLE_USERNAME_OR_HOMEDIR
        {
                struct passwd *entry;
@@ -1981,7 +2231,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 #endif
 
 #if 0
-       for (i = 0; i <= MAX_HISTORY; i++)
+       for (i = 0; i <= state->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
@@ -1990,6 +2240,11 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
        parse_and_put_prompt(prompt);
        ask_terminal();
 
+       /* Install window resize handler (NB: after *all* init is complete) */
+//FIXME: save entire sigaction!
+       previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
+       win_changed(0); /* get initial window size */
+
        read_key_buffer[0] = 0;
        while (1) {
                /*
@@ -2000,15 +2255,14 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                 * 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, ic_raw;
 
                fflush_all();
-               ic = ic_raw = lineedit_read_key(read_key_buffer);
+               ic = ic_raw = lineedit_read_key(read_key_buffer, timeout);
 
+#if ENABLE_FEATURE_REVERSE_SEARCH
+ again:
+#endif
 #if ENABLE_FEATURE_EDITING_VI
                newdelflag = 1;
                if (vi_cmdmode) {
@@ -2075,7 +2329,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                case CTRL('L'):
                vi_case(CTRL('L')|VI_CMDMODE_BIT:)
                        /* Control-l -- clear screen */
-                       printf("\033[H"); /* cursor to top,left */
+                       printf(ESC"[H"); /* cursor to top,left */
                        redraw(0, command_len - cursor);
                        break;
 #if MAX_HISTORY > 0
@@ -2112,6 +2366,11 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                        while (cursor > 0 && !BB_isspace(command_ps[cursor-1]))
                                input_backspace();
                        break;
+#if ENABLE_FEATURE_REVERSE_SEARCH
+               case CTRL('R'):
+                       ic = ic_raw = reverse_i_search();
+                       goto again;
+#endif
 
 #if ENABLE_FEATURE_EDITING_VI
                case 'i'|VI_CMDMODE_BIT:
@@ -2168,9 +2427,9 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                case 'd'|VI_CMDMODE_BIT: {
                        int nc, sc;
 
-                       ic = lineedit_read_key(read_key_buffer);
+                       ic = lineedit_read_key(read_key_buffer, timeout);
                        if (errno) /* error */
-                               goto prepare_to_die;
+                               goto return_error_indicator;
                        if (ic == ic_raw) { /* "cc", "dd" */
                                input_backward(cursor);
                                goto clear_to_eol;
@@ -2232,9 +2491,9 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                        break;
                case 'r'|VI_CMDMODE_BIT:
 //FIXME: unicode case?
-                       ic = lineedit_read_key(read_key_buffer);
+                       ic = lineedit_read_key(read_key_buffer, timeout);
                        if (errno) /* error */
-                               goto prepare_to_die;
+                               goto return_error_indicator;
                        if (ic < ' ' || ic > 255) {
                                beep();
                        } else {
@@ -2265,7 +2524,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                        /* Rewrite the line with the selected history item */
                        /* change command */
                        command_len = load_string(state->history[state->cur_history] ?
-                                       state->history[state->cur_history] : "", maxsize);
+                                       state->history[state->cur_history] : "");
                        /* redraw and go to eol (bol, in vi) */
                        redraw(cmdedit_y, (state->flags & VI_MODE) ? 9999 : 0);
                        break;
@@ -2306,9 +2565,9 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                                 * or exit if len=0 and no chars to delete */
                                if (command_len == 0) {
                                        errno = 0;
-#if ENABLE_FEATURE_EDITING_VI
- prepare_to_die:
-#endif
+
+               case -1: /* error (e.g. EIO when tty is destroyed) */
+ IF_FEATURE_EDITING_VI(return_error_indicator:)
                                        break_out = command_len = -1;
                                        break;
                                }
@@ -2318,7 +2577,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 //                     /* Control-V -- force insert of next char */
 //                     if (c == CTRL('V')) {
 //                             if (safe_read(STDIN_FILENO, &c, 1) < 1)
-//                                     goto prepare_to_die;
+//                                     goto return_error_indicator;
 //                             if (c == 0) {
 //                                     beep();
 //                                     break;