Imported from /srv/lorry/lorry-area/less/less-451.tar.gz.HEADless-451masterbaserock/morph

1 files changed, 841 insertions, 0 deletions

diff --git a/decode.c b/decode.c
new file mode 100755
index 0000000..6d0312d
--- /dev/null
+++ b/decode.c
@@ -0,0 +1,841 @@
+/*
+ * Copyright (C) 1984-2012  Mark Nudelman
+ *
+ * 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 "less.h"
+#include "cmd.h"
+#include "lesskey.h"
+
+extern int erase_char, erase2_char, kill_char;
+extern int secure;
+
+#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,
+	'-',0,				A_OPT_TOGGLE,
+	':','t',0,			A_OPT_TOGGLE|A_EXTRA,	't',0,
+	's',0,				A_OPT_TOGGLE|A_EXTRA,	'o',0,
+	'_',0,				A_DISP_OPTION,
+	'|',0,				A_PIPE,
+	'v',0,				A_VISUAL,
+	'!',0,				A_SHELL,
+	'+',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 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(table, len)
+	char *table;
+	int len;
+{
+	register char *fm;
+	register char *to;
+	register 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 || (int) 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.
+ */
+	public void
+init_cmds()
+{
+	/*
+	 * Add the default command tables.
+	 */
+	add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
+	add_ecmd_table((char*)edittable, sizeof(edittable));
+#if USERFILE
+	/*
+	 * For backwards compatibility,
+	 * try to add tables in the OLD system lesskey file.
+	 */
+#ifdef BINDIR
+	add_hometable(NULL, BINDIR "/.sysless", 1);
+#endif
+	/*
+	 * 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);
+#endif
+}
+
+/*
+ * Add a command table.
+ */
+	static int
+add_cmd_table(tlist, buf, len)
+	struct tablelist **tlist;
+	char *buf;
+	int len;
+{
+	register struct tablelist *t;
+
+	if (len == 0)
+		return (0);
+	/*
+	 * Allocate a tablelist structure, initialize it, 
+	 * and link it into the list of tables.
+	 */
+	if ((t = (struct tablelist *) 
+			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.
+ */
+	public void
+add_fcmd_table(buf, len)
+	char *buf;
+	int len;
+{
+	if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
+		error("Warning: some commands disabled", NULL_PARG);
+}
+
+/*
+ * Add an editing command table.
+ */
+	public void
+add_ecmd_table(buf, len)
+	char *buf;
+	int len;
+{
+	if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
+		error("Warning: some edit commands disabled", NULL_PARG);
+}
+
+/*
+ * Add an environment variable table.
+ */
+	static void
+add_var_table(tlist, buf, len)
+	struct tablelist **tlist;
+	char *buf;
+	int len;
+{
+	if (add_cmd_table(tlist, buf, len) < 0)
+		error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
+}
+
+/*
+ * Search a single command table for the command string in cmd.
+ */
+	static int
+cmd_search(cmd, table, endtable, sp)
+	char *cmd;
+	char *table;
+	char *endtable;
+	char **sp;
+{
+	register char *p;
+	register char *q;
+	register 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(tlist, cmd, sp)
+	struct tablelist *tlist;
+	char *cmd;
+	char **sp;
+{
+	register struct tablelist *t;
+	register 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.
+ */
+	public int
+fcmd_decode(cmd, sp)
+	char *cmd;
+	char **sp;
+{
+	return (cmd_decode(list_fcmd_tables, cmd, sp));
+}
+
+/*
+ * Decode a command from the edittables list.
+ */
+	public int
+ecmd_decode(cmd, sp)
+	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.
+ */
+	public char *
+lgetenv(var)
+	char *var;
+{
+	int a;
+	char *s;
+
+	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);
+}
+
+#if USERFILE
+/*
+ * 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(sp)
+	char **sp;
+{
+	int n;
+
+	n = *(*sp)++;
+	n += *(*sp)++ * KRADIX;
+	return (n);
+}
+
+/*
+ * Process an old (pre-v241) lesskey file.
+ */
+	static int
+old_lesskey(buf, len)
+	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(buf, len, sysvar)
+	char *buf;
+	int len;
+	int sysvar;
+{
+	char *p;
+	register int c;
+	register 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;
+	for (;;)
+	{
+		c = *p++;
+		switch (c)
+		{
+		case CMD_SECTION:
+			n = gint(&p);
+			add_fcmd_table(p, n);
+			p += n;
+			break;
+		case EDIT_SECTION:
+			n = gint(&p);
+			add_ecmd_table(p, n);
+			p += n;
+			break;
+		case VAR_SECTION:
+			n = gint(&p);
+			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.
+ */
+	public int
+lesskey(filename, sysvar)
+	char *filename;
+	int sysvar;
+{
+	register char *buf;
+	register POSITION len;
+	register long n;
+	register int f;
+
+	if (secure)
+		return (1);
+	/*
+	 * Try to open the lesskey file.
+	 */
+	filename = shell_unquote(filename);
+	f = open(filename, OPEN_READ);
+	free(filename);
+	if (f < 0)
+		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 == NULL_POSITION || len < 3)
+	{
+		/*
+		 * Bad file (valid file must have at least 3 chars).
+		 */
+		close(f);
+		return (-1);
+	}
+	if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
+	{
+		close(f);
+		return (-1);
+	}
+	if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
+	{
+		free(buf);
+		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 (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"
+ */
+	public void
+add_hometable(envname, def_filename, sysvar)
+	char *envname;
+	char *def_filename;
+	int sysvar;
+{
+	char *filename;
+	PARG parg;
+
+	if (envname != NULL && (filename = lgetenv(envname)) != NULL)
+		filename = save(filename);
+	else if (sysvar)
+		filename = save(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);
+}
+#endif
+
+/*
+ * See if a char is a special line-editing command.
+ */
+	public int
+editchar(c, flags)
+	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] = 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 CMD_HISTORY
+	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;
+		}
+	}
+#endif
+#if TAB_COMPLETE_FILENAME
+	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;
+		}
+	}
+#endif
+	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;
+}
+