Adding upstream version 3:4.8.29.upstream/3%4.8.29upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1482 insertions, 0 deletions

diff --git a/lib/widget/input_complete.c b/lib/widget/input_complete.c
new file mode 100644
index 0000000..c7fa555
--- /dev/null
+++ b/lib/widget/input_complete.c
@@ -0,0 +1,1482 @@
+/*
+   Input line filename/username/hostname/variable/command completion.
+   (Let mc type for you...)
+
+   Copyright (C) 1995-2022
+   Free Software Foundation, Inc.
+
+   Written by:
+   Jakub Jelinek, 1995
+   Slava Zanko <slavazanko@gmail.com>, 2013
+   Andrew Borodin <aborodin@vmail.ru>, 2013-2022
+
+   This file is part of the Midnight Commander.
+
+   The Midnight Commander is free software: you can redistribute it
+   and/or modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   The Midnight Commander is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file lib/widget/input_complete.c
+ *  \brief Source: Input line filename/username/hostname/variable/command completion
+ */
+
+#include <config.h>
+
+#include <ctype.h>
+#include <limits.h>             /* MB_LEN_MAX */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <pwd.h>
+#include <unistd.h>
+
+#include "lib/global.h"
+
+#include "lib/tty/tty.h"
+#include "lib/tty/key.h"        /* XCTRL and ALT macros */
+#include "lib/vfs/vfs.h"
+#include "lib/strescape.h"
+#include "lib/strutil.h"
+#include "lib/util.h"
+#include "lib/widget.h"
+
+/*** global variables ****************************************************************************/
+
+/* Linux declares environ in <unistd.h>, so don't repeat it here. */
+#if (!(defined(__linux__) && defined (__USE_GNU)) && !defined(__CYGWIN__))
+extern char **environ;
+#endif
+
+/*** file scope macro definitions ****************************************************************/
+
+/* #define DO_COMPLETION_DEBUG */
+#ifdef DO_COMPLETION_DEBUG
+#define SHOW_C_CTX(func) fprintf(stderr, "%s: text='%s' flags=%s\n", func, text, show_c_flags(flags))
+#else
+#define SHOW_C_CTX(func)
+#endif /* DO_CMPLETION_DEBUG */
+
+#define DO_INSERTION 1
+#define DO_QUERY     2
+
+/*** file scope type declarations ****************************************************************/
+
+typedef char *CompletionFunction (const char *text, int state, input_complete_t flags);
+
+typedef struct
+{
+    size_t in_command_position;
+    char *word;
+    char *p;
+    char *q;
+    char *r;
+    gboolean is_cd;
+    input_complete_t flags;
+} try_complete_automation_state_t;
+
+/*** file scope variables ************************************************************************/
+
+static char **hosts = NULL;
+static char **hosts_p = NULL;
+static int hosts_alloclen = 0;
+
+static int complete_height, complete_width;
+static WInput *input;
+static int min_end;
+static int start = 0;
+static int end = 0;
+
+/*** file scope functions ************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+char **try_complete (char *text, int *lc_start, int *lc_end, input_complete_t flags);
+void complete_engine_fill_completions (WInput * in);
+
+#ifdef DO_COMPLETION_DEBUG
+/**
+ * Useful to print/debug completion flags
+ */
+static const char *
+show_c_flags (input_complete_t flags)
+{
+    static char s_cf[] = "FHCVUDS";
+
+    s_cf[0] = (flags & INPUT_COMPLETE_FILENAMES) != 0 ? 'F' : ' ';
+    s_cf[1] = (flags & INPUT_COMPLETE_HOSTNAMES) != 0 ? 'H' : ' ';
+    s_cf[2] = (flags & INPUT_COMPLETE_COMMANDS) != 0 ? 'C' : ' ';
+    s_cf[3] = (flags & INPUT_COMPLETE_VARIABLES) != 0 ? 'V' : ' ';
+    s_cf[4] = (flags & INPUT_COMPLETE_USERNAMES) != 0 ? 'U' : ' ';
+    s_cf[5] = (flags & INPUT_COMPLETE_CD) != 0 ? 'D' : ' ';
+    s_cf[6] = (flags & INPUT_COMPLETE_SHELL_ESC) != 0 ? 'S' : ' ';
+
+    return s_cf;
+}
+#endif /* DO_CMPLETION_DEBUG */
+
+/* --------------------------------------------------------------------------------------------- */
+
+static char *
+filename_completion_function (const char *text, int state, input_complete_t flags)
+{
+    static DIR *directory = NULL;
+    static char *filename = NULL;
+    static char *dirname = NULL;
+    static char *users_dirname = NULL;
+    static size_t filename_len = 0;
+    static vfs_path_t *dirname_vpath = NULL;
+
+    gboolean isdir = TRUE, isexec = FALSE;
+    struct vfs_dirent *entry = NULL;
+
+    SHOW_C_CTX ("filename_completion_function");
+
+    if (text != NULL && (flags & INPUT_COMPLETE_SHELL_ESC) != 0)
+    {
+        char *u_text;
+        char *result;
+        char *e_result;
+
+        u_text = strutils_shell_unescape (text);
+
+        result = filename_completion_function (u_text, state, flags & (~INPUT_COMPLETE_SHELL_ESC));
+        g_free (u_text);
+
+        e_result = strutils_shell_escape (result);
+        g_free (result);
+
+        return e_result;
+    }
+
+    /* If we're starting the match process, initialize us a bit. */
+    if (state == 0)
+    {
+        const char *temp;
+
+        g_free (dirname);
+        g_free (filename);
+        g_free (users_dirname);
+        vfs_path_free (dirname_vpath, TRUE);
+
+        if ((*text != '\0') && (temp = strrchr (text, PATH_SEP)) != NULL)
+        {
+            filename = g_strdup (++temp);
+            dirname = g_strndup (text, temp - text);
+        }
+        else
+        {
+            dirname = g_strdup (".");
+            filename = g_strdup (text);
+        }
+
+        /* We aren't done yet.  We also support the "~user" syntax. */
+
+        /* Save the version of the directory that the user typed. */
+        users_dirname = dirname;
+        dirname = tilde_expand (dirname);
+        canonicalize_pathname (dirname);
+        dirname_vpath = vfs_path_from_str (dirname);
+
+        /* Here we should do something with variable expansion
+           and `command`.
+           Maybe a dream - UNIMPLEMENTED yet. */
+
+        directory = mc_opendir (dirname_vpath);
+        filename_len = strlen (filename);
+    }
+
+    /* Now that we have some state, we can read the directory. */
+
+    while (directory != NULL && (entry = mc_readdir (directory)) != NULL)
+    {
+        if (!str_is_valid_string (entry->d_name))
+            continue;
+
+        /* Special case for no filename.
+           All entries except "." and ".." match. */
+        if (filename_len == 0)
+        {
+            if (DIR_IS_DOT (entry->d_name) || DIR_IS_DOTDOT (entry->d_name))
+                continue;
+        }
+        else
+        {
+            /* Otherwise, if these match up to the length of filename, then
+               it may be a match. */
+            if ((entry->d_name[0] != filename[0]) ||
+                ((NLENGTH (entry)) < filename_len) ||
+                strncmp (filename, entry->d_name, filename_len) != 0)
+                continue;
+        }
+
+        isdir = TRUE;
+        isexec = FALSE;
+
+        {
+            struct stat tempstat;
+            vfs_path_t *tmp_vpath;
+
+            tmp_vpath = vfs_path_build_filename (dirname, entry->d_name, (char *) NULL);
+
+            /* Unix version */
+            if (mc_stat (tmp_vpath, &tempstat) == 0)
+            {
+                uid_t my_uid;
+                gid_t my_gid;
+
+                my_uid = getuid ();
+                my_gid = getgid ();
+
+                if (!S_ISDIR (tempstat.st_mode))
+                {
+                    isdir = FALSE;
+
+                    if ((my_uid == 0 && (tempstat.st_mode & 0111) != 0) ||
+                        (my_uid == tempstat.st_uid && (tempstat.st_mode & 0100) != 0) ||
+                        (my_gid == tempstat.st_gid && (tempstat.st_mode & 0010) != 0) ||
+                        (tempstat.st_mode & 0001) != 0)
+                        isexec = TRUE;
+                }
+            }
+            else
+            {
+                /* stat failed, strange. not a dir in any case */
+                isdir = FALSE;
+            }
+            vfs_path_free (tmp_vpath, TRUE);
+        }
+
+        if ((flags & INPUT_COMPLETE_COMMANDS) != 0 && (isexec || isdir))
+            break;
+        if ((flags & INPUT_COMPLETE_CD) != 0 && isdir)
+            break;
+        if ((flags & INPUT_COMPLETE_FILENAMES) != 0)
+            break;
+    }
+
+    if (entry == NULL)
+    {
+        if (directory != NULL)
+        {
+            mc_closedir (directory);
+            directory = NULL;
+        }
+        MC_PTR_FREE (dirname);
+        vfs_path_free (dirname_vpath, TRUE);
+        dirname_vpath = NULL;
+        MC_PTR_FREE (filename);
+        MC_PTR_FREE (users_dirname);
+        return NULL;
+    }
+
+    {
+        GString *temp;
+
+        temp = g_string_sized_new (16);
+
+        if (users_dirname != NULL && (users_dirname[0] != '.' || users_dirname[1] != '\0'))
+        {
+            g_string_append (temp, users_dirname);
+
+            /* We need a '/' at the end. */
+            if (!IS_PATH_SEP (temp->str[temp->len - 1]))
+                g_string_append_c (temp, PATH_SEP);
+        }
+        g_string_append (temp, entry->d_name);
+        if (isdir)
+            g_string_append_c (temp, PATH_SEP);
+
+        return g_string_free (temp, FALSE);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/** We assume here that text[0] == '~' , if you want to call it in another way,
+   you have to change the code */
+
+static char *
+username_completion_function (const char *text, int state, input_complete_t flags)
+{
+    static struct passwd *entry = NULL;
+    static size_t userlen = 0;
+
+    (void) flags;
+    SHOW_C_CTX ("username_completion_function");
+
+    if (text[0] == '\\' && text[1] == '~')
+        text++;
+    if (state == 0)
+    {                           /* Initialization stuff */
+        setpwent ();
+        userlen = strlen (text + 1);
+    }
+
+    while ((entry = getpwent ()) != NULL)
+    {
+        /* Null usernames should result in all users as possible completions. */
+        if (userlen == 0)
+            break;
+        if (text[1] == entry->pw_name[0] && strncmp (text + 1, entry->pw_name, userlen) == 0)
+            break;
+    }
+
+    if (entry != NULL)
+        return g_strconcat ("~", entry->pw_name, PATH_SEP_STR, (char *) NULL);
+
+    endpwent ();
+    return NULL;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/** We assume text [0] == '$' and want to have a look at text [1], if it is
+   equal to '{', so that we should append '}' at the end */
+
+static char *
+variable_completion_function (const char *text, int state, input_complete_t flags)
+{
+    static char **env_p = NULL;
+    static gboolean isbrace = FALSE;
+    static size_t varlen = 0;
+    const char *p = NULL;
+
+    (void) flags;
+    SHOW_C_CTX ("variable_completion_function");
+
+    if (state == 0)
+    {                           /* Initialization stuff */
+        isbrace = (text[1] == '{');
+        varlen = strlen (text + 1 + isbrace);
+        env_p = environ;
+    }
+
+    while (*env_p != NULL)
+    {
+        p = strchr (*env_p, '=');
+        if (p != NULL && ((size_t) (p - *env_p) >= varlen)
+            && strncmp (text + 1 + isbrace, *env_p, varlen) == 0)
+            break;
+        env_p++;
+    }
+
+    if (*env_p == NULL)
+        return NULL;
+
+    {
+        GString *temp;
+
+        temp = g_string_new_len (*env_p, p - *env_p);
+
+        if (isbrace)
+        {
+            g_string_prepend_c (temp, '{');
+            g_string_append_c (temp, '}');
+        }
+        g_string_prepend_c (temp, '$');
+
+        env_p++;
+
+        return g_string_free (temp, FALSE);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+fetch_hosts (const char *filename)
+{
+    FILE *file;
+    char buffer[256];
+    char *name;
+    char *lc_start;
+    char *bi;
+
+    file = fopen (filename, "r");
+    if (file == NULL)
+        return;
+
+    while (fgets (buffer, sizeof (buffer) - 1, file) != NULL)
+    {
+        /* Skip to first character. */
+        for (bi = buffer; bi[0] != '\0' && str_isspace (bi); str_next_char (&bi))
+            ;
+
+        /* Ignore comments... */
+        if (bi[0] == '#')
+            continue;
+
+        /* Handle $include. */
+        if (strncmp (bi, "$include ", 9) == 0)
+        {
+            char *includefile, *t;
+
+            /* Find start of filename. */
+            includefile = bi + 9;
+            while (*includefile != '\0' && whitespace (*includefile))
+                includefile++;
+            t = includefile;
+
+            /* Find end of filename. */
+            while (t[0] != '\0' && !str_isspace (t))
+                str_next_char (&t);
+            *t = '\0';
+
+            fetch_hosts (includefile);
+            continue;
+        }
+
+        /* Skip IP #s. */
+        while (bi[0] != '\0' && !str_isspace (bi))
+            str_next_char (&bi);
+
+        /* Get the host names separated by white space. */
+        while (bi[0] != '\0' && bi[0] != '#')
+        {
+            while (bi[0] != '\0' && str_isspace (bi))
+                str_next_char (&bi);
+            if (bi[0] == '#')
+                continue;
+            for (lc_start = bi; bi[0] != '\0' && !str_isspace (bi); str_next_char (&bi))
+                ;
+
+            if (bi == lc_start)
+                continue;
+
+            name = g_strndup (lc_start, bi - lc_start);
+
+            {
+                char **host_p;
+                int j;
+
+                j = hosts_p - hosts;
+
+                if (j >= hosts_alloclen)
+                {
+                    hosts_alloclen += 30;
+                    hosts = g_renew (char *, hosts, hosts_alloclen + 1);
+                    hosts_p = hosts + j;
+                }
+
+                for (host_p = hosts; host_p < hosts_p; host_p++)
+                    if (strcmp (name, *host_p) == 0)
+                        break;  /* We do not want any duplicates */
+
+                if (host_p == hosts_p)
+                {
+                    *(hosts_p++) = name;
+                    *hosts_p = NULL;
+                }
+                else
+                    g_free (name);
+            }
+        }
+    }
+
+    fclose (file);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static char *
+hostname_completion_function (const char *text, int state, input_complete_t flags)
+{
+    static char **host_p = NULL;
+    static size_t textstart = 0;
+    static size_t textlen = 0;
+
+    (void) flags;
+    SHOW_C_CTX ("hostname_completion_function");
+
+    if (state == 0)
+    {                           /* Initialization stuff */
+        const char *p;
+
+        g_strfreev (hosts);
+        hosts_alloclen = 30;
+        hosts = g_new (char *, hosts_alloclen + 1);
+        *hosts = NULL;
+        hosts_p = hosts;
+        p = getenv ("HOSTFILE");
+        fetch_hosts (p != NULL ? p : "/etc/hosts");
+        host_p = hosts;
+        textstart = (*text == '@') ? 1 : 0;
+        textlen = strlen (text + textstart);
+    }
+
+    for (; *host_p != NULL; host_p++)
+    {
+        if (textlen == 0)
+            break;              /* Match all of them */
+        if (strncmp (text + textstart, *host_p, textlen) == 0)
+            break;
+    }
+
+    if (*host_p == NULL)
+    {
+        g_strfreev (hosts);
+        hosts = NULL;
+        return NULL;
+    }
+
+    {
+        GString *temp;
+
+        temp = g_string_sized_new (8);
+
+        if (textstart != 0)
+            g_string_append_c (temp, '@');
+        g_string_append (temp, *host_p);
+        host_p++;
+
+        return g_string_free (temp, FALSE);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/**
+ * This is the function to call when the word to complete is in a position
+ * where a command word can be found. It looks around $PATH, looking for
+ * commands that match. It also scans aliases, function names, and the
+ * table of shell built-ins.
+ */
+
+static char *
+command_completion_function (const char *text, int state, input_complete_t flags)
+{
+    static const char *path_end = NULL;
+    static gboolean isabsolute = FALSE;
+    static int phase = 0;
+    static size_t text_len = 0;
+    static const char *const *words = NULL;
+    static char *path = NULL;
+    static char *cur_path = NULL;
+    static char *cur_word = NULL;
+    static int init_state = 0;
+    static const char *const bash_reserved[] = {
+        "if", "then", "else", "elif", "fi", "case", "esac", "for",
+        "select", "while", "until", "do", "done", "in", "function", 0
+    };
+    static const char *const bash_builtins[] = {
+        "alias", "bg", "bind", "break", "builtin", "cd", "command",
+        "continue", "declare", "dirs", "echo", "enable", "eval",
+        "exec", "exit", "export", "fc", "fg", "getopts", "hash",
+        "help", "history", "jobs", "kill", "let", "local", "logout",
+        "popd", "pushd", "pwd", "read", "readonly", "return", "set",
+        "shift", "source", "suspend", "test", "times", "trap", "type",
+        "typeset", "ulimit", "umask", "unalias", "unset", "wait", 0
+    };
+
+    char *u_text;
+    char *p, *found;
+
+    SHOW_C_CTX ("command_completion_function");
+
+    if ((flags & INPUT_COMPLETE_COMMANDS) == 0)
+        return NULL;
+
+    u_text = strutils_shell_unescape (text);
+    flags &= ~INPUT_COMPLETE_SHELL_ESC;
+
+    if (state == 0)
+    {                           /* Initialize us a little bit */
+        isabsolute = strchr (u_text, PATH_SEP) != NULL;
+        if (!isabsolute)
+        {
+            words = bash_reserved;
+            phase = 0;
+            text_len = strlen (u_text);
+
+            if (path == NULL)
+            {
+                path = g_strdup (getenv ("PATH"));
+                if (path != NULL)
+                {
+                    p = path;
+                    path_end = strchr (p, '\0');
+                    while ((p = strchr (p, PATH_ENV_SEP)) != NULL)
+                        *p++ = '\0';
+                }
+            }
+        }
+    }
+
+    if (isabsolute)
+    {
+        p = filename_completion_function (u_text, state, flags);
+
+        if (p != NULL)
+        {
+            char *temp_p = p;
+
+            p = strutils_shell_escape (p);
+            g_free (temp_p);
+        }
+
+        g_free (u_text);
+        return p;
+    }
+
+    found = NULL;
+    switch (phase)
+    {
+    case 0:                    /* Reserved words */
+        for (; *words != NULL; words++)
+            if (strncmp (*words, u_text, text_len) == 0)
+            {
+                g_free (u_text);
+                return g_strdup (*(words++));
+            }
+        phase++;
+        words = bash_builtins;
+        MC_FALLTHROUGH;
+    case 1:                    /* Builtin commands */
+        for (; *words != NULL; words++)
+            if (strncmp (*words, u_text, text_len) == 0)
+            {
+                g_free (u_text);
+                return g_strdup (*(words++));
+            }
+        phase++;
+        if (path == NULL)
+            break;
+        cur_path = path;
+        cur_word = NULL;
+        MC_FALLTHROUGH;
+    case 2:                    /* And looking through the $PATH */
+        while (found == NULL)
+        {
+            if (cur_word == NULL)
+            {
+                char *expanded;
+
+                if (cur_path >= path_end)
+                    break;
+                expanded = tilde_expand (*cur_path != '\0' ? cur_path : ".");
+                cur_word = mc_build_filename (expanded, u_text, (char *) NULL);
+                g_free (expanded);
+                canonicalize_pathname (cur_word);
+                cur_path = strchr (cur_path, '\0') + 1;
+                init_state = state;
+            }
+            found = filename_completion_function (cur_word, state - init_state, flags);
+            if (found == NULL)
+                MC_PTR_FREE (cur_word);
+        }
+        MC_FALLTHROUGH;
+    default:
+        break;
+    }
+
+    if (found == NULL)
+        MC_PTR_FREE (path);
+    else
+    {
+        p = strrchr (found, PATH_SEP);
+        if (p != NULL)
+        {
+            char *tmp = found;
+
+            found = strutils_shell_escape (p + 1);
+            g_free (tmp);
+        }
+    }
+
+    g_free (u_text);
+    return found;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static int
+match_compare (const void *a, const void *b)
+{
+    return strcmp (*(char *const *) a, *(char *const *) b);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/** Returns an array of char * matches with the longest common denominator
+   in the 1st entry. Then a NULL terminated list of different possible
+   completions follows.
+   You have to supply your own CompletionFunction with the word you
+   want to complete as the first argument and an count of previous matches
+   as the second. 
+   In case no matches were found we return NULL. */
+
+static char **
+completion_matches (const char *text, CompletionFunction entry_function, input_complete_t flags)
+{
+    /* Number of slots in match_list. */
+    size_t match_list_size = 30;
+    /* The list of matches. */
+    char **match_list;
+    /* Number of matches actually found. */
+    size_t matches = 0;
+
+    /* Temporary string binder. */
+    char *string;
+
+    match_list = g_new (char *, match_list_size + 1);
+    match_list[1] = NULL;
+
+    while ((string = (*entry_function) (text, matches, flags)) != NULL)
+    {
+        if (matches + 1 == match_list_size)
+        {
+            match_list_size += 30;
+            match_list = (char **) g_renew (char *, match_list, match_list_size + 1);
+        }
+        match_list[++matches] = string;
+        match_list[matches + 1] = NULL;
+    }
+
+    /* If there were any matches, then look through them finding out the
+       lowest common denominator.  That then becomes match_list[0]. */
+    if (matches == 0)
+        MC_PTR_FREE (match_list);       /* There were no matches. */
+    else
+    {
+        /* If only one match, just use that. */
+        if (matches == 1)
+        {
+            match_list[0] = match_list[1];
+            match_list[1] = NULL;
+        }
+        else
+        {
+            size_t i = 1;
+            int low = 4096;     /* Count of max-matched characters. */
+            size_t j;
+
+            qsort (match_list + 1, matches, sizeof (char *), match_compare);
+
+            /* And compare each member of the list with
+               the next, finding out where they stop matching. 
+               If we find two equal strings, we have to put one away... */
+
+            j = i + 1;
+            while (j < matches + 1)
+            {
+                char *si, *sj;
+                char *ni, *nj;
+
+                for (si = match_list[i], sj = match_list[j]; si[0] != '\0' && sj[0] != '\0';)
+                {
+
+                    ni = str_get_next_char (si);
+                    nj = str_get_next_char (sj);
+
+                    if (ni - si != nj - sj)
+                        break;
+                    if (strncmp (si, sj, ni - si) != 0)
+                        break;
+
+                    si = ni;
+                    sj = nj;
+                }
+
+                if (si[0] == '\0' && sj[0] == '\0')
+                {               /* Two equal strings */
+                    g_free (match_list[j]);
+                    j++;
+                    if (j > matches)
+                        break;
+                    continue;   /* Look for a run of equal strings */
+                }
+                else if (low > si - match_list[i])
+                    low = si - match_list[i];
+                if (i + 1 != j) /* So there's some gap */
+                    match_list[i + 1] = match_list[j];
+                i++;
+                j++;
+            }
+            matches = i;
+            match_list[matches + 1] = NULL;
+            match_list[0] = g_strndup (match_list[1], low);
+        }
+    }
+
+    return match_list;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/** Check if directory completion is needed */
+static gboolean
+check_is_cd (const char *text, int lc_start, input_complete_t flags)
+{
+    const char *p, *q;
+
+    SHOW_C_CTX ("check_is_cd");
+
+    if ((flags & INPUT_COMPLETE_CD) == 0)
+        return FALSE;
+
+    /* Skip initial spaces */
+    p = text;
+    q = text + lc_start;
+    while (p < q && p[0] != '\0' && str_isspace (p))
+        str_cnext_char (&p);
+
+    /* Check if the command is "cd" and the cursor is after it */
+    return (p[0] == 'c' && p[1] == 'd' && str_isspace (p + 2) && p + 2 < q);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+try_complete_commands_prepare (try_complete_automation_state_t * state, char *text, int *lc_start)
+{
+    const char *command_separator_chars = ";|&{(`";
+    char *ti;
+
+    if (*lc_start == 0)
+        ti = text;
+    else
+    {
+        ti = str_get_prev_char (&text[*lc_start]);
+        while (ti > text && whitespace (ti[0]))
+            str_prev_char (&ti);
+    }
+
+    if (ti == text)
+        state->in_command_position++;
+    else if (strchr (command_separator_chars, ti[0]) != NULL)
+    {
+        state->in_command_position++;
+        if (ti != text)
+        {
+            int this_char, prev_char;
+
+            /* Handle the two character tokens '>&', '<&', and '>|'.
+               We are not in a command position after one of these. */
+            this_char = ti[0];
+            prev_char = str_get_prev_char (ti)[0];
+
+            /* Quoted */
+            if ((this_char == '&' && (prev_char == '<' || prev_char == '>'))
+                || (this_char == '|' && prev_char == '>') || (ti != text
+                                                              && str_get_prev_char (ti)[0] == '\\'))
+                state->in_command_position = 0;
+        }
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+try_complete_find_start_sign (try_complete_automation_state_t * state)
+{
+    if ((state->flags & INPUT_COMPLETE_COMMANDS) != 0)
+        state->p = strrchr (state->word, '`');
+    if ((state->flags & (INPUT_COMPLETE_COMMANDS | INPUT_COMPLETE_VARIABLES)) != 0)
+    {
+        state->q = strrchr (state->word, '$');
+
+        /* don't substitute variable in \$ case */
+        if (strutils_is_char_escaped (state->word, state->q))
+        {
+            /* drop '\\' */
+            str_move (state->q - 1, state->q);
+            /* adjust flags */
+            state->flags &= ~INPUT_COMPLETE_VARIABLES;
+            state->q = NULL;
+        }
+    }
+    if ((state->flags & INPUT_COMPLETE_HOSTNAMES) != 0)
+        state->r = strrchr (state->word, '@');
+    if (state->q != NULL && state->q[1] == '(' && (state->flags & INPUT_COMPLETE_COMMANDS) != 0)
+    {
+        if (state->q > state->p)
+            state->p = str_get_next_char (state->q);
+        state->q = NULL;
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static char **
+try_complete_all_possible (try_complete_automation_state_t * state, char *text, int *lc_start)
+{
+    char **matches = NULL;
+
+    if (state->in_command_position != 0)
+    {
+        SHOW_C_CTX ("try_complete:cmd_subst");
+        matches =
+            completion_matches (state->word, command_completion_function,
+                                state->flags & (~INPUT_COMPLETE_FILENAMES));
+    }
+    else if ((state->flags & INPUT_COMPLETE_FILENAMES) != 0)
+    {
+        if (state->is_cd)
+            state->flags &= ~(INPUT_COMPLETE_FILENAMES | INPUT_COMPLETE_COMMANDS);
+        SHOW_C_CTX ("try_complete:filename_subst_1");
+        matches = completion_matches (state->word, filename_completion_function, state->flags);
+
+        if (matches == NULL && state->is_cd && !IS_PATH_SEP (*state->word) && *state->word != '~')
+        {
+            state->q = text + *lc_start;
+            for (state->p = text;
+                 *state->p != '\0' && state->p < state->q && whitespace (*state->p);
+                 str_next_char (&state->p))
+                ;
+            if (strncmp (state->p, "cd", 2) == 0)
+                for (state->p += 2;
+                     *state->p != '\0' && state->p < state->q && whitespace (*state->p);
+                     str_next_char (&state->p))
+                    ;
+            if (state->p == state->q)
+            {
+                char *cdpath_ref, *cdpath;
+                char c;
+
+                cdpath_ref = g_strdup (getenv ("CDPATH"));
+                cdpath = cdpath_ref;
+                c = (cdpath == NULL) ? '\0' : ':';
+
+                while (matches == NULL && c == ':')
+                {
+                    char *s;
+
+                    s = strchr (cdpath, ':');
+                    /* cppcheck-suppress nullPointer */
+                    if (s == NULL)
+                        s = strchr (cdpath, '\0');
+                    c = *s;
+                    *s = '\0';
+                    if (*cdpath != '\0')
+                    {
+                        state->r = mc_build_filename (cdpath, state->word, (char *) NULL);
+                        SHOW_C_CTX ("try_complete:filename_subst_2");
+                        matches =
+                            completion_matches (state->r, filename_completion_function,
+                                                state->flags);
+                        g_free (state->r);
+                    }
+                    *s = c;
+                    cdpath = str_get_next_char (s);
+                }
+                g_free (cdpath_ref);
+            }
+        }
+    }
+    return matches;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static gboolean
+insert_text (WInput * in, char *text, ssize_t size)
+{
+    size_t text_len;
+    int buff_len;
+    ssize_t new_size;
+
+    text_len = strlen (text);
+    buff_len = str_length (in->buffer->str);
+    if (size < 0)
+        size = (ssize_t) text_len;
+    else
+        size = MIN (size, (ssize_t) text_len);
+
+    new_size = size + start - end;
+    if (new_size != 0)
+    {
+        /* make a hole within buffer */
+
+        size_t tail_len;
+
+        tail_len = in->buffer->len - end;
+        if (tail_len != 0)
+        {
+            char *tail;
+            size_t hole_end;
+
+            tail = g_strndup (in->buffer->str + end, tail_len);
+
+            hole_end = end + new_size;
+            if (in->buffer->len < hole_end)
+                g_string_set_size (in->buffer, hole_end + tail_len);
+
+            g_string_overwrite_len (in->buffer, hole_end, tail, tail_len);
+
+            g_free (tail);
+        }
+    }
+
+    g_string_overwrite_len (in->buffer, start, text, size);
+
+    in->point += str_length (in->buffer->str) - buff_len;
+    input_update (in, TRUE);
+    end += new_size;
+
+    return new_size != 0;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static cb_ret_t
+complete_callback (Widget * w, Widget * sender, widget_msg_t msg, int parm, void *data)
+{
+    static int bl = 0;
+
+    WGroup *g = GROUP (w);
+    WDialog *h = DIALOG (w);
+
+    switch (msg)
+    {
+    case MSG_KEY:
+        switch (parm)
+        {
+        case KEY_LEFT:
+        case KEY_RIGHT:
+            bl = 0;
+            h->ret_value = 0;
+            dlg_stop (h);
+            return MSG_HANDLED;
+
+        case KEY_BACKSPACE:
+            bl = 0;
+            /* exit from completion list if input line is empty */
+            if (end == 0)
+            {
+                h->ret_value = 0;
+                dlg_stop (h);
+            }
+            /* Refill the list box and start again */
+            else if (end == min_end)
+            {
+                end = str_get_prev_char (input->buffer->str + end) - input->buffer->str;
+                input_handle_char (input, parm);
+                h->ret_value = B_USER;
+                dlg_stop (h);
+            }
+            else
+            {
+                int new_end;
+                int i;
+                GList *e;
+
+                new_end = str_get_prev_char (input->buffer->str + end) - input->buffer->str;
+
+                for (i = 0, e = listbox_get_first_link (LISTBOX (g->current->data));
+                     e != NULL; i++, e = g_list_next (e))
+                {
+                    WLEntry *le = LENTRY (e->data);
+
+                    if (strncmp (input->buffer->str + start, le->text, new_end - start) == 0)
+                    {
+                        listbox_select_entry (LISTBOX (g->current->data), i);
+                        end = new_end;
+                        input_handle_char (input, parm);
+                        widget_draw (WIDGET (g->current->data));
+                        break;
+                    }
+                }
+            }
+            return MSG_HANDLED;
+
+        default:
+            if (parm < 32 || parm > 255)
+            {
+                bl = 0;
+                if (widget_lookup_key (WIDGET (input), parm) != CK_Complete)
+                    return MSG_NOT_HANDLED;
+
+                if (end == min_end)
+                    return MSG_HANDLED;
+
+                /* This means we want to refill the list box and start again */
+                h->ret_value = B_USER;
+                dlg_stop (h);
+            }
+            else
+            {
+                static char buff[MB_LEN_MAX] = "";
+                GList *e;
+                int i;
+                int need_redraw = 0;
+                int low = 4096;
+                char *last_text = NULL;
+
+                buff[bl++] = (char) parm;
+                buff[bl] = '\0';
+
+                switch (str_is_valid_char (buff, bl))
+                {
+                case -1:
+                    bl = 0;
+                    MC_FALLTHROUGH;
+                case -2:
+                    return MSG_HANDLED;
+                default:
+                    break;
+                }
+
+                for (i = 0, e = listbox_get_first_link (LISTBOX (g->current->data));
+                     e != NULL; i++, e = g_list_next (e))
+                {
+                    WLEntry *le = LENTRY (e->data);
+
+                    if (strncmp (input->buffer->str + start, le->text, end - start) == 0
+                        && strncmp (le->text + end - start, buff, bl) == 0)
+                    {
+                        if (need_redraw == 0)
+                        {
+                            need_redraw = 1;
+                            listbox_select_entry (LISTBOX (g->current->data), i);
+                            last_text = le->text;
+                        }
+                        else
+                        {
+                            char *si, *sl;
+                            int si_num = 0;
+                            int sl_num = 0;
+
+                            /* count symbols between start and end */
+                            for (si = le->text + start; si < le->text + end;
+                                 str_next_char (&si), si_num++)
+                                ;
+                            for (sl = last_text + start; sl < last_text + end;
+                                 str_next_char (&sl), sl_num++)
+                                ;
+
+                            /* pointers to next symbols */
+                            si = &le->text[str_offset_to_pos (le->text, ++si_num)];
+                            sl = &last_text[str_offset_to_pos (last_text, ++sl_num)];
+
+                            while (si[0] != '\0' && sl[0] != '\0')
+                            {
+                                char *nexti, *nextl;
+
+                                nexti = str_get_next_char (si);
+                                nextl = str_get_next_char (sl);
+
+                                if (nexti - si != nextl - sl || strncmp (si, sl, nexti - si) != 0)
+                                    break;
+
+                                si = nexti;
+                                sl = nextl;
+
+                                si_num++;
+                            }
+
+                            last_text = le->text;
+
+                            si = &last_text[str_offset_to_pos (last_text, si_num)];
+                            if (low > si - last_text)
+                                low = si - last_text;
+
+                            need_redraw = 2;
+                        }
+                    }
+                }
+
+                if (need_redraw == 2)
+                {
+                    insert_text (input, last_text, low);
+                    widget_draw (WIDGET (g->current->data));
+                }
+                else if (need_redraw == 1)
+                {
+                    h->ret_value = B_ENTER;
+                    dlg_stop (h);
+                }
+                bl = 0;
+            }
+        }
+        return MSG_HANDLED;
+
+    default:
+        return dlg_default_callback (w, sender, msg, parm, data);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/** Returns TRUE if the user would like to see us again */
+static gboolean
+complete_engine (WInput * in, int what_to_do)
+{
+    if (in->completions != NULL && str_offset_to_pos (in->buffer->str, in->point) != end)
+        input_complete_free (in);
+
+    if (in->completions == NULL)
+        complete_engine_fill_completions (in);
+
+    if (in->completions == NULL)
+        tty_beep ();
+    else
+    {
+        if ((what_to_do & DO_INSERTION) != 0
+            || ((what_to_do & DO_QUERY) != 0 && in->completions[1] == NULL))
+        {
+            char *lc_complete = in->completions[0];
+
+            if (!insert_text (in, lc_complete, -1) || in->completions[1] != NULL)
+                tty_beep ();
+            else
+                input_complete_free (in);
+        }
+
+        if ((what_to_do & DO_QUERY) != 0 && in->completions != NULL && in->completions[1] != NULL)
+        {
+            int maxlen = 0, count = 0, i;
+            int x, y, w, h;
+            int start_x, start_y;
+            char **p, *q;
+            WDialog *complete_dlg;
+            WListbox *complete_list;
+
+            for (p = in->completions + 1; *p != NULL; count++, p++)
+            {
+                i = str_term_width1 (*p);
+                if (i > maxlen)
+                    maxlen = i;
+            }
+
+            start_x = WIDGET (in)->rect.x;
+            start_y = WIDGET (in)->rect.y;
+            if (start_y - 2 >= count)
+            {
+                y = start_y - 2 - count;
+                h = 2 + count;
+            }
+            else if (start_y >= LINES - start_y - 1)
+            {
+                y = 0;
+                h = start_y;
+            }
+            else
+            {
+                y = start_y + 1;
+                h = LINES - start_y - 1;
+            }
+            x = start - in->term_first_shown - 2 + start_x;
+            w = maxlen + 4;
+            if (x + w > COLS)
+                x = COLS - w;
+            if (x < 0)
+                x = 0;
+            if (x + w > COLS)
+                w = COLS;
+
+            input = in;
+            min_end = end;
+            complete_height = h;
+            complete_width = w;
+
+            complete_dlg =
+                dlg_create (TRUE, y, x, complete_height, complete_width, WPOS_KEEP_DEFAULT, TRUE,
+                            dialog_colors, complete_callback, NULL, "[Completion]", NULL);
+            complete_list = listbox_new (1, 1, h - 2, w - 2, FALSE, NULL);
+            group_add_widget (GROUP (complete_dlg), complete_list);
+
+            for (p = in->completions + 1; *p != NULL; p++)
+                listbox_add_item (complete_list, LISTBOX_APPEND_AT_END, 0, *p, NULL, FALSE);
+
+            i = dlg_run (complete_dlg);
+            q = NULL;
+            if (i == B_ENTER)
+            {
+                listbox_get_current (complete_list, &q, NULL);
+                if (q != NULL)
+                    insert_text (in, q, -1);
+            }
+            if (q != NULL || end != min_end)
+                input_complete_free (in);
+            widget_destroy (WIDGET (complete_dlg));
+
+            /* B_USER if user wants to start over again */
+            return (i == B_USER);
+        }
+    }
+
+    return FALSE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/*** public functions ****************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+/** Returns an array of matches, or NULL if none. */
+char **
+try_complete (char *text, int *lc_start, int *lc_end, input_complete_t flags)
+{
+    try_complete_automation_state_t state;
+    char **matches = NULL;
+
+    memset (&state, 0, sizeof (state));
+    state.flags = flags;
+
+    SHOW_C_CTX ("try_complete");
+    state.word = g_strndup (text + *lc_start, *lc_end - *lc_start);
+
+    state.is_cd = check_is_cd (text, *lc_start, state.flags);
+
+    /* Determine if this could be a command word. It is if it appears at
+       the start of the line (ignoring preceding whitespace), or if it
+       appears after a character that separates commands. And we have to
+       be in a INPUT_COMPLETE_COMMANDS flagged Input line. */
+    if (!state.is_cd && (flags & INPUT_COMPLETE_COMMANDS) != 0)
+        try_complete_commands_prepare (&state, text, lc_start);
+
+    try_complete_find_start_sign (&state);
+
+    /* Command substitution? */
+    if (state.p > state.q && state.p > state.r)
+    {
+        SHOW_C_CTX ("try_complete:cmd_backq_subst");
+        matches = completion_matches (str_cget_next_char (state.p),
+                                      command_completion_function,
+                                      state.flags & (~INPUT_COMPLETE_FILENAMES));
+        if (matches != NULL)
+            *lc_start += str_get_next_char (state.p) - state.word;
+    }
+
+    /* Variable name? */
+    else if (state.q > state.p && state.q > state.r)
+    {
+        SHOW_C_CTX ("try_complete:var_subst");
+        matches = completion_matches (state.q, variable_completion_function, state.flags);
+        if (matches != NULL)
+            *lc_start += state.q - state.word;
+    }
+
+    /* Starts with '@', then look through the known hostnames for 
+       completion first. */
+    else if (state.r > state.p && state.r > state.q)
+    {
+        SHOW_C_CTX ("try_complete:host_subst");
+        matches = completion_matches (state.r, hostname_completion_function, state.flags);
+        if (matches != NULL)
+            *lc_start += state.r - state.word;
+    }
+
+    /* Starts with '~' and there is no slash in the word, then
+       try completing this word as a username. */
+    if (matches == NULL && *state.word == '~' && (state.flags & INPUT_COMPLETE_USERNAMES) != 0
+        && strchr (state.word, PATH_SEP) == NULL)
+    {
+        SHOW_C_CTX ("try_complete:user_subst");
+        matches = completion_matches (state.word, username_completion_function, state.flags);
+    }
+
+    /* If this word is in a command position, then
+       complete over possible command names, including aliases, functions,
+       and command names. */
+    if (matches == NULL)
+        matches = try_complete_all_possible (&state, text, lc_start);
+
+    /* And finally if nothing found, try complete directory name */
+    if (matches == NULL)
+    {
+        state.in_command_position = 0;
+        matches = try_complete_all_possible (&state, text, lc_start);
+    }
+
+    g_free (state.word);
+
+    if (matches != NULL &&
+        (flags & (INPUT_COMPLETE_FILENAMES | INPUT_COMPLETE_SHELL_ESC)) !=
+        (INPUT_COMPLETE_FILENAMES | INPUT_COMPLETE_SHELL_ESC))
+    {
+        /* FIXME: HACK? INPUT_COMPLETE_SHELL_ESC is used only in command line. */
+        char **m;
+
+        for (m = matches; *m != NULL; m++)
+        {
+            char *p;
+
+            p = *m;
+            *m = strutils_shell_escape (*m);
+            g_free (p);
+        }
+    }
+
+    return matches;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+void
+complete_engine_fill_completions (WInput * in)
+{
+    char *s;
+    const char *word_separators;
+
+    word_separators = (in->completion_flags & INPUT_COMPLETE_SHELL_ESC) ? " \t;|<>" : "\t;|<>";
+
+    end = str_offset_to_pos (in->buffer->str, in->point);
+
+    s = in->buffer->str;
+    if (in->point != 0)
+    {
+        /* get symbol before in->point */
+        size_t i;
+
+        for (i = in->point - 1; i > 0; i--)
+            str_next_char (&s);
+    }
+
+    for (; s >= in->buffer->str; str_prev_char (&s))
+    {
+        start = s - in->buffer->str;
+        if (strchr (word_separators, *s) != NULL && !strutils_is_char_escaped (in->buffer->str, s))
+            break;
+    }
+
+    if (start < end)
+    {
+        str_next_char (&s);
+        start = s - in->buffer->str;
+    }
+
+    in->completions = try_complete (in->buffer->str, &start, &end, in->completion_flags);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/* declared in lib/widget/input.h */
+void
+input_complete (WInput * in)
+{
+    int engine_flags;
+
+    if (!str_is_valid_string (in->buffer->str))
+        return;
+
+    if (in->completions != NULL)
+        engine_flags = DO_QUERY;
+    else
+    {
+        engine_flags = DO_INSERTION;
+
+        if (mc_global.widget.show_all_if_ambiguous)
+            engine_flags |= DO_QUERY;
+    }
+
+    while (complete_engine (in, engine_flags))
+        ;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+void
+input_complete_free (WInput * in)
+{
+    g_strfreev (in->completions);
+    in->completions = NULL;
+}
+
+/* --------------------------------------------------------------------------------------------- */