/*
 * Copyright (C) 1984-2012  Mark Nudelman
 * Modified for use with illumos by Garrett D'Amore.
 * Copyright 2014 Garrett D'Amore <garrett@damore.org>
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Less License, as specified in the README file.
 *
 * For more information, see the README file.
 */

/*
 * Routines to decode user commands.
 *
 * This is all table driven.
 * A command table is a sequence of command descriptors.
 * Each command descriptor is a sequence of bytes with the following format:
 *      <c1><c2>...<cN><0><action>
 * The characters c1,c2,...,cN are the command string; that is,
 * the characters which the user must type.
 * It is terminated by a null <0> byte.
 * The byte after the null byte is the action code associated
 * with the command string.
 * If an action byte is OR-ed with A_EXTRA, this indicates
 * that the option byte is followed by an extra string.
 *
 * There may be many command tables.
 * The first (default) table is built-in.
 * Other tables are read in from "lesskey" files.
 * All the tables are linked together and are searched in order.
 */

#include "cmd.h"
#include "less.h"
#include "lesskey.h"

extern int erase_char, erase2_char, kill_char;
extern int secure, less_is_more;

#define SK(k) \
        SK_SPECIAL_KEY, (k), 6, 1, 1, 1
/*
 * Command table is ordered roughly according to expected
 * frequency of use, so the common commands are near the beginning.
 */

static unsigned char cmdtable[] =
{
        '\r', 0,                        A_F_LINE,
        '\n', 0,                        A_F_LINE,
        'e', 0,                         A_F_LINE,
        'j', 0,                         A_F_LINE,
        SK(SK_DOWN_ARROW), 0,           A_F_LINE,
        CONTROL('E'), 0,                A_F_LINE,
        CONTROL('N'), 0,                A_F_LINE,
        'k', 0,                         A_B_LINE,
        'y', 0,                         A_B_LINE,
        CONTROL('Y'), 0,                A_B_LINE,
        SK(SK_CONTROL_K), 0,            A_B_LINE,
        CONTROL('P'), 0,                A_B_LINE,
        SK(SK_UP_ARROW), 0,             A_B_LINE,
        'J', 0,                         A_FF_LINE,
        'K', 0,                         A_BF_LINE,
        'Y', 0,                         A_BF_LINE,
        'd', 0,                         A_F_SCROLL,
        CONTROL('D'), 0,                A_F_SCROLL,
        'u', 0,                         A_B_SCROLL,
        CONTROL('U'), 0,                A_B_SCROLL,
        ' ', 0,                         A_F_SCREEN,
        'f', 0,                         A_F_SCREEN,
        CONTROL('F'), 0,                A_F_SCREEN,
        CONTROL('V'), 0,                A_F_SCREEN,
        SK(SK_PAGE_DOWN), 0,            A_F_SCREEN,
        'b', 0,                         A_B_SCREEN,
        CONTROL('B'), 0,                A_B_SCREEN,
        ESC, 'v', 0,                    A_B_SCREEN,
        SK(SK_PAGE_UP), 0,              A_B_SCREEN,
        'z', 0,                         A_F_WINDOW,
        'w', 0,                         A_B_WINDOW,
        ESC, ' ', 0,                    A_FF_SCREEN,
        'F', 0,                         A_F_FOREVER,
        ESC, 'F', 0,                    A_F_UNTIL_HILITE,
        'R', 0,                         A_FREPAINT,
        'r', 0,                         A_REPAINT,
        CONTROL('R'), 0,                A_REPAINT,
        CONTROL('L'), 0,                A_REPAINT,
        ESC, 'u', 0,                    A_UNDO_SEARCH,
        'g', 0,                         A_GOLINE,
        SK(SK_HOME), 0,                 A_GOLINE,
        '<', 0,                         A_GOLINE,
        ESC, '<', 0,                    A_GOLINE,
        'p', 0,                         A_PERCENT,
        '%', 0,                         A_PERCENT,
        ESC, '[', 0,                    A_LSHIFT,
        ESC, ']', 0,                    A_RSHIFT,
        ESC, '(', 0,                    A_LSHIFT,
        ESC, ')', 0,                    A_RSHIFT,
        SK(SK_RIGHT_ARROW), 0,          A_RSHIFT,
        SK(SK_LEFT_ARROW), 0,           A_LSHIFT,
        '{', 0,                         A_F_BRACKET|A_EXTRA,    '{', '}', 0,
        '}', 0,                         A_B_BRACKET|A_EXTRA,    '{', '}', 0,
        '(', 0,                         A_F_BRACKET|A_EXTRA,    '(', ')', 0,
        ')', 0,                         A_B_BRACKET|A_EXTRA,    '(', ')', 0,
        '[', 0,                         A_F_BRACKET|A_EXTRA,    '[', ']', 0,
        ']', 0,                         A_B_BRACKET|A_EXTRA,    '[', ']', 0,
        ESC, CONTROL('F'), 0,           A_F_BRACKET,
        ESC, CONTROL('B'), 0,           A_B_BRACKET,
        'G', 0,                         A_GOEND,
        ESC, '>', 0,                    A_GOEND,
        '>', 0,                         A_GOEND,
        SK(SK_END), 0,                  A_GOEND,
        'P', 0,                         A_GOPOS,

        '0', 0,                         A_DIGIT,
        '1', 0,                         A_DIGIT,
        '2', 0,                         A_DIGIT,
        '3', 0,                         A_DIGIT,
        '4', 0,                         A_DIGIT,
        '5', 0,                         A_DIGIT,
        '6', 0,                         A_DIGIT,
        '7', 0,                         A_DIGIT,
        '8', 0,                         A_DIGIT,
        '9', 0,                         A_DIGIT,
        '.', 0,                         A_DIGIT,

        '=', 0,                         A_STAT,
        CONTROL('G'), 0,                A_STAT,
        ':', 'f', 0,                    A_STAT,
        '/', 0,                         A_F_SEARCH,
        '?', 0,                         A_B_SEARCH,
        ESC, '/', 0,                    A_F_SEARCH|A_EXTRA,     '*', 0,
        ESC, '?', 0,                    A_B_SEARCH|A_EXTRA,     '*', 0,
        'n', 0,                         A_AGAIN_SEARCH,
        ESC, 'n', 0,                    A_T_AGAIN_SEARCH,
        'N', 0,                         A_REVERSE_SEARCH,
        ESC, 'N', 0,                    A_T_REVERSE_SEARCH,
        '&', 0,                         A_FILTER,
        'm', 0,                         A_SETMARK,
        '\'', 0,                        A_GOMARK,
        CONTROL('X'), CONTROL('X'), 0,  A_GOMARK,
        'E', 0,                         A_EXAMINE,
        ':', 'e', 0,                    A_EXAMINE,
        CONTROL('X'), CONTROL('V'), 0,  A_EXAMINE,
        ':', 'n', 0,                    A_NEXT_FILE,
        ':', 'p', 0,                    A_PREV_FILE,
        't', 0,                         A_NEXT_TAG,
        'T', 0,                         A_PREV_TAG,
        ':', 'x', 0,                    A_INDEX_FILE,
        ':', 'd', 0,                    A_REMOVE_FILE,
        ':', 't', 0,                    A_OPT_TOGGLE|A_EXTRA,   't', 0,
        '|', 0,                         A_PIPE,
        'v', 0,                         A_VISUAL,
        '+', 0,                         A_FIRSTCMD,

        'H', 0,                         A_HELP,
        'h', 0,                         A_HELP,
        SK(SK_F1), 0,                   A_HELP,
        'V', 0,                         A_VERSION,
        'q', 0,                         A_QUIT,
        'Q', 0,                         A_QUIT,
        ':', 'q', 0,                    A_QUIT,
        ':', 'Q', 0,                    A_QUIT,
        'Z', 'Z', 0,                    A_QUIT
};

static unsigned char lesstable[] = {
        '-', 0,                         A_OPT_TOGGLE,
        's', 0,                         A_OPT_TOGGLE|A_EXTRA,   'o', 0,
        '_', 0,                         A_DISP_OPTION
};

static unsigned char moretable[] = {
        's', 0,                         A_F_SKIP
};

static unsigned char edittable[] =
{
        '\t', 0,                        EC_F_COMPLETE,  /* TAB */
        '\17', 0,                       EC_B_COMPLETE,  /* BACKTAB */
        SK(SK_BACKTAB), 0,              EC_B_COMPLETE,  /* BACKTAB */
        ESC, '\t', 0,                   EC_B_COMPLETE,  /* ESC TAB */
        CONTROL('L'), 0,                EC_EXPAND,      /* CTRL-L */
        CONTROL('V'), 0,                EC_LITERAL,     /* BACKSLASH */
        CONTROL('A'), 0,                EC_LITERAL,     /* BACKSLASH */
        ESC, 'l', 0,                    EC_RIGHT,       /* ESC l */
        SK(SK_RIGHT_ARROW), 0,          EC_RIGHT,       /* RIGHTARROW */
        ESC, 'h', 0,                    EC_LEFT,        /* ESC h */
        SK(SK_LEFT_ARROW), 0,           EC_LEFT,        /* LEFTARROW */
        ESC, 'b', 0,                    EC_W_LEFT,      /* ESC b */
        ESC, SK(SK_LEFT_ARROW), 0,      EC_W_LEFT,      /* ESC LEFTARROW */
        SK(SK_CTL_LEFT_ARROW), 0,       EC_W_LEFT,      /* CTRL-LEFTARROW */
        ESC, 'w', 0,                    EC_W_RIGHT,     /* ESC w */
        ESC, SK(SK_RIGHT_ARROW), 0,     EC_W_RIGHT,     /* ESC RIGHTARROW */
        SK(SK_CTL_RIGHT_ARROW), 0,      EC_W_RIGHT,     /* CTRL-RIGHTARROW */
        ESC, 'i', 0,                    EC_INSERT,      /* ESC i */
        SK(SK_INSERT), 0,               EC_INSERT,      /* INSERT */
        ESC, 'x', 0,                    EC_DELETE,      /* ESC x */
        SK(SK_DELETE), 0,               EC_DELETE,      /* DELETE */
        ESC, 'X', 0,                    EC_W_DELETE,    /* ESC X */
        ESC, SK(SK_DELETE), 0,          EC_W_DELETE,    /* ESC DELETE */
        SK(SK_CTL_DELETE), 0,           EC_W_DELETE,    /* CTRL-DELETE */
        SK(SK_CTL_BACKSPACE), 0,        EC_W_BACKSPACE, /* CTRL-BACKSPACE */
        ESC, '\b', 0,                   EC_W_BACKSPACE, /* ESC BACKSPACE */
        ESC, '0', 0,                    EC_HOME,        /* ESC 0 */
        SK(SK_HOME), 0,                 EC_HOME,        /* HOME */
        ESC, '$', 0,                    EC_END,         /* ESC $ */
        SK(SK_END), 0,                  EC_END,         /* END */
        ESC, 'k', 0,                    EC_UP,          /* ESC k */
        SK(SK_UP_ARROW), 0,             EC_UP,          /* UPARROW */
        ESC, 'j', 0,                    EC_DOWN,        /* ESC j */
        SK(SK_DOWN_ARROW), 0,           EC_DOWN,        /* DOWNARROW */
        CONTROL('G'), 0,                EC_ABORT,       /* CTRL-G */
};

/*
 * Structure to support a list of command tables.
 */
struct tablelist {
        struct tablelist *t_next;
        char *t_start;
        char *t_end;
};

/*
 * List of command tables and list of line-edit tables.
 */
static struct tablelist *list_fcmd_tables = NULL;
static struct tablelist *list_ecmd_tables = NULL;
static struct tablelist *list_var_tables = NULL;
static struct tablelist *list_sysvar_tables = NULL;


/*
 * Expand special key abbreviations in a command table.
 */
static void
expand_special_keys(char *table, int len)
{
        char *fm;
        char *to;
        int a;
        char *repl;
        int klen;

        for (fm = table; fm < table + len; ) {
                /*
                 * Rewrite each command in the table with any
                 * special key abbreviations expanded.
                 */
                for (to = fm; *fm != '\0'; ) {
                        if (*fm != SK_SPECIAL_KEY) {
                                *to++ = *fm++;
                                continue;
                        }
                        /*
                         * After SK_SPECIAL_KEY, next byte is the type
                         * of special key (one of the SK_* contants),
                         * and the byte after that is the number of bytes,
                         * N, reserved by the abbreviation (including the
                         * SK_SPECIAL_KEY and key type bytes).
                         * Replace all N bytes with the actual bytes
                         * output by the special key on this terminal.
                         */
                        repl = special_key_str(fm[1]);
                        klen = fm[2] & 0377;
                        fm += klen;
                        if (repl == NULL || strlen(repl) > klen)
                                repl = "\377";
                        while (*repl != '\0')
                                *to++ = *repl++;
                }
                *to++ = '\0';
                /*
                 * Fill any unused bytes between end of command and
                 * the action byte with A_SKIP.
                 */
                while (to <= fm)
                        *to++ = A_SKIP;
                fm++;
                a = *fm++ & 0377;
                if (a & A_EXTRA) {
                        while (*fm++ != '\0')
                                continue;
                }
        }
}

/*
 * Initialize the command lists.
 */
void
init_cmds(void)
{
        /*
         * Add the default command tables.
         */
        add_fcmd_table((char *)cmdtable, sizeof (cmdtable));
        add_ecmd_table((char *)edittable, sizeof (edittable));
        if (less_is_more) {
                add_fcmd_table((char *)moretable, sizeof (moretable));
                return;
        } else {
                add_fcmd_table((char *)lesstable, sizeof (lesstable));
        }

        /*
         * Try to add the tables in the system lesskey file.
         */
        add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
        /*
         * Try to add the tables in the standard lesskey file "$HOME/.less".
         */
        add_hometable("LESSKEY", LESSKEYFILE, 0);
}

/*
 * Add a command table.
 */
static int
add_cmd_table(struct tablelist **tlist, char *buf, int len)
{
        struct tablelist *t;

        if (len == 0)
                return (0);
        /*
         * Allocate a tablelist structure, initialize it,
         * and link it into the list of tables.
         */
        if ((t = calloc(1, sizeof (struct tablelist))) == NULL) {
                return (-1);
        }
        expand_special_keys(buf, len);
        t->t_start = buf;
        t->t_end = buf + len;
        t->t_next = *tlist;
        *tlist = t;
        return (0);
}

/*
 * Add a command table.
 */
void
add_fcmd_table(char *buf, int len)
{
        if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
                error("Warning: some commands disabled", NULL);
}

/*
 * Add an editing command table.
 */
void
add_ecmd_table(char *buf, int len)
{
        if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
                error("Warning: some edit commands disabled", NULL);
}

/*
 * Add an environment variable table.
 */
static void
add_var_table(struct tablelist **tlist, char *buf, int len)
{
        if (add_cmd_table(tlist, buf, len) < 0)
                error("Warning: environment variables from "
                    "lesskey file unavailable", NULL);
}

/*
 * Search a single command table for the command string in cmd.
 */
static int
cmd_search(const char *cmd, char *table, char *endtable, char **sp)
{
        char *p;
        const char *q;
        int a;

        *sp = NULL;
        for (p = table, q = cmd; p < endtable; p++, q++) {
                if (*p == *q) {
                        /*
                         * Current characters match.
                         * If we're at the end of the string, we've found it.
                         * Return the action code, which is the character
                         * after the null at the end of the string
                         * in the command table.
                         */
                        if (*p == '\0') {
                                a = *++p & 0377;
                                while (a == A_SKIP)
                                        a = *++p & 0377;
                                if (a == A_END_LIST) {
                                        /*
                                         * We get here only if the original
                                         * cmd string passed in was empty ("").
                                         * I don't think that can happen,
                                         * but just in case ...
                                         */
                                        return (A_UINVALID);
                                }
                                /*
                                 * Check for an "extra" string.
                                 */
                                if (a & A_EXTRA) {
                                        *sp = ++p;
                                        a &= ~A_EXTRA;
                                }
                                return (a);
                        }
                } else if (*q == '\0') {
                        /*
                         * Hit the end of the user's command,
                         * but not the end of the string in the command table.
                         * The user's command is incomplete.
                         */
                        return (A_PREFIX);
                } else {
                        /*
                         * Not a match.
                         * Skip ahead to the next command in the
                         * command table, and reset the pointer
                         * to the beginning of the user's command.
                         */
                        if (*p == '\0' && p[1] == A_END_LIST) {
                                /*
                                 * A_END_LIST is a special marker that tells
                                 * us to abort the cmd search.
                                 */
                                return (A_UINVALID);
                        }
                        while (*p++ != '\0')
                                continue;
                        while (*p == A_SKIP)
                                p++;
                        if (*p & A_EXTRA)
                                while (*++p != '\0')
                                        continue;
                        q = cmd-1;
                }
        }
        /*
         * No match found in the entire command table.
         */
        return (A_INVALID);
}

/*
 * Decode a command character and return the associated action.
 * The "extra" string, if any, is returned in sp.
 */
static int
cmd_decode(struct tablelist *tlist, const char *cmd, char **sp)
{
        struct tablelist *t;
        int action = A_INVALID;

        /*
         * Search thru all the command tables.
         * Stop when we find an action which is not A_INVALID.
         */
        for (t = tlist; t != NULL; t = t->t_next) {
                action = cmd_search(cmd, t->t_start, t->t_end, sp);
                if (action != A_INVALID)
                        break;
        }
        if (action == A_UINVALID)
                action = A_INVALID;
        return (action);
}

/*
 * Decode a command from the cmdtables list.
 */
int
fcmd_decode(const char *cmd, char **sp)
{
        return (cmd_decode(list_fcmd_tables, cmd, sp));
}

/*
 * Decode a command from the edittables list.
 */
int
ecmd_decode(const char *cmd, char **sp)
{
        return (cmd_decode(list_ecmd_tables, cmd, sp));
}

/*
 * Get the value of an environment variable.
 * Looks first in the lesskey file, then in the real environment.
 */
char *
lgetenv(char *var)
{
        int a;
        char *s;

        /*
         * Ignore lookups of any LESS* setting when we are more, and ignore
         * the less key files
         */
        if (less_is_more) {
                if (strncmp(var, "LESS", 4) == 0) {
                        return (NULL);
                }
                return (getenv(var));
        }
        a = cmd_decode(list_var_tables, var, &s);
        if (a == EV_OK)
                return (s);
        s = getenv(var);
        if (s != NULL && *s != '\0')
                return (s);
        a = cmd_decode(list_sysvar_tables, var, &s);
        if (a == EV_OK)
                return (s);
        return (NULL);
}

/*
 * Get an "integer" from a lesskey file.
 * Integers are stored in a funny format:
 * two bytes, low order first, in radix KRADIX.
 */
static int
gint(char **sp)
{
        int n;

        n = *(*sp)++;
        n += *(*sp)++ * KRADIX;
        return (n);
}

/*
 * Process an old (pre-v241) lesskey file.
 */
static int
old_lesskey(char *buf, int len)
{
        /*
         * Old-style lesskey file.
         * The file must end with either
         *      ..,cmd,0,action
         * or   ...,cmd,0,action|A_EXTRA,string,0
         * So the last byte or the second to last byte must be zero.
         */
        if (buf[len-1] != '\0' && buf[len-2] != '\0')
                return (-1);
        add_fcmd_table(buf, len);
        return (0);
}

/*
 * Process a new (post-v241) lesskey file.
 */
static int
new_lesskey(char *buf, int len, int sysvar)
{
        char *p;
        char *end;
        int c;
        int n;

        /*
         * New-style lesskey file.
         * Extract the pieces.
         */
        if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
            buf[len-2] != C1_END_LESSKEY_MAGIC ||
            buf[len-1] != C2_END_LESSKEY_MAGIC)
                return (-1);
        p = buf + 4;
        end = buf + len;
        for (;;) {
                c = *p++;
                switch (c) {
                case CMD_SECTION:
                        n = gint(&p);
                        if (n < 0 || p + n >= end)
                                return (-1);
                        add_fcmd_table(p, n);
                        p += n;
                        break;
                case EDIT_SECTION:
                        n = gint(&p);
                        if (n < 0 || p + n >= end)
                                return (-1);
                        add_ecmd_table(p, n);
                        p += n;
                        break;
                case VAR_SECTION:
                        n = gint(&p);
                        if (n < 0 || p + n >= end)
                                return (-1);
                        add_var_table((sysvar) ?
                            &list_sysvar_tables : &list_var_tables, p, n);
                        p += n;
                        break;
                case END_SECTION:
                        return (0);
                default:
                        /*
                         * Unrecognized section type.
                         */
                        return (-1);
                }
        }
}

/*
 * Set up a user command table, based on a "lesskey" file.
 */
int
lesskey(char *filename, int sysvar)
{
        char *buf;
        off_t len;
        long n;
        int f;

        if (secure)
                return (1);
        /*
         * Try to open the lesskey file.
         */
        filename = shell_unquote(filename);
        f = open(filename, O_RDONLY);
        free(filename);
        if (f == -1)
                return (1);

        /*
         * Read the file into a buffer.
         * We first figure out the size of the file and allocate space for it.
         * {{ Minimal error checking is done here.
         *    A garbage .less file will produce strange results.
         *    To avoid a large amount of error checking code here, we
         *    rely on the lesskey program to generate a good .less file. }}
         */
        len = filesize(f);
        if (len == -1 || len < 3) {
                /*
                 * Bad file (valid file must have at least 3 chars).
                 */
                (void) close(f);
                return (-1);
        }
        if ((buf = calloc((int)len, sizeof (char))) == NULL) {
                (void) close(f);
                return (-1);
        }
        if (lseek(f, (off_t)0, SEEK_SET) == (off_t)-1) {
                free(buf);
                (void) close(f);
                return (-1);
        }
        n = read(f, buf, (unsigned int) len);
        close(f);
        if (n != len) {
                free(buf);
                return (-1);
        }

        /*
         * Figure out if this is an old-style (before version 241)
         * or new-style lesskey file format.
         */
        if (len < 4 ||
            buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
            buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
                return (old_lesskey(buf, (int)len));
        return (new_lesskey(buf, (int)len, sysvar));
}

/*
 * Add the standard lesskey file "$HOME/.less"
 */
void
add_hometable(char *envname, char *def_filename, int sysvar)
{
        char *filename;
        PARG parg;

        if (envname != NULL && (filename = lgetenv(envname)) != NULL)
                filename = estrdup(filename);
        else if (sysvar)
                filename = estrdup(def_filename);
        else
                filename = homefile(def_filename);
        if (filename == NULL)
                return;
        if (lesskey(filename, sysvar) < 0) {
                parg.p_string = filename;
                error("Cannot use lesskey file \"%s\"", &parg);
        }
        free(filename);
}

/*
 * See if a char is a special line-editing command.
 */
int
editchar(int c, int flags)
{
        int action;
        int nch;
        char *s;
        char usercmd[MAX_CMDLEN+1];

        /*
         * An editing character could actually be a sequence of characters;
         * for example, an escape sequence sent by pressing the uparrow key.
         * To match the editing string, we use the command decoder
         * but give it the edit-commands command table
         * This table is constructed to match the user's keyboard.
         */
        if (c == erase_char || c == erase2_char)
                return (EC_BACKSPACE);
        if (c == kill_char)
                return (EC_LINEKILL);

        /*
         * Collect characters in a buffer.
         * Start with the one we have, and get more if we need them.
         */
        nch = 0;
        do {
                if (nch > 0)
                        c = getcc();
                usercmd[nch] = (char)c;
                usercmd[nch+1] = '\0';
                nch++;
                action = ecmd_decode(usercmd, &s);
        } while (action == A_PREFIX);

        if (flags & EC_NORIGHTLEFT) {
                switch (action) {
                case EC_RIGHT:
                case EC_LEFT:
                        action = A_INVALID;
                        break;
                }
        }
        if (flags & EC_NOHISTORY) {
                /*
                 * The caller says there is no history list.
                 * Reject any history-manipulation action.
                 */
                switch (action) {
                case EC_UP:
                case EC_DOWN:
                        action = A_INVALID;
                        break;
                }
        }
        if (flags & EC_NOCOMPLETE) {
                /*
                 * The caller says we don't want any filename completion cmds.
                 * Reject them.
                 */
                switch (action) {
                case EC_F_COMPLETE:
                case EC_B_COMPLETE:
                case EC_EXPAND:
                        action = A_INVALID;
                        break;
                }
        }
        if ((flags & EC_PEEK) || action == A_INVALID) {
                /*
                 * We're just peeking, or we didn't understand the command.
                 * Unget all the characters we read in the loop above.
                 * This does NOT include the original character that was
                 * passed in as a parameter.
                 */
                while (nch > 1) {
                        ungetcc(usercmd[--nch]);
                }
        } else {
                if (s != NULL)
                        ungetsc(s);
        }
        return (action);
}