src/hci/readline.c - ipxe - Git at Google

 /*
  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
  *
  * This program 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 2 of the
  * License, or any later version.
  *
  * This program 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, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301, USA.
  *
  * You can also choose to distribute this program under the terms of
  * the Unmodified Binary Distribution Licence (as given in the file
  * COPYING.UBDL), provided that you have satisfied its requirements.
  */

 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <ipxe/console.h>
 #include <ipxe/keys.h>
 #include <ipxe/editstring.h>
 #include <readline/readline.h>

 /** @file
  *
  * Minimal readline
  *
  */

 #define READLINE_MAX 1024

 /**
  * Synchronise console with edited string
  *
  * @v string		Editable string
  */
 static void sync_console ( struct edit_string *string ) {
 	unsigned int mod_start = string->mod_start;
 	unsigned int mod_end = string->mod_end;
 	unsigned int cursor = string->last_cursor;
 	size_t len = strlen ( string->buf );

 	/* Expand region back to old cursor position if applicable */
 	if ( mod_start > string->last_cursor )
 		mod_start = string->last_cursor;

 	/* Expand region forward to new cursor position if applicable */
 	if ( mod_end < string->cursor )
 		mod_end = string->cursor;

 	/* Backspace to start of region */
 	while ( cursor > mod_start ) {
 		putchar ( '\b' );
 		cursor--;
 	}

 	/* Print modified region */
 	while ( cursor < mod_end ) {
 		putchar ( ( cursor >= len ) ? ' ' : string->buf[cursor] );
 		cursor++;
 	}

 	/* Backspace to new cursor position */
 	while ( cursor > string->cursor ) {
 		putchar ( '\b' );
 		cursor--;
 	}
 }

 /**
  * Locate history entry
  *
  * @v history		History buffer
  * @v depth		Depth within history buffer
  * @ret entry		History entry
  */
 static struct readline_history_entry *
 history_entry ( struct readline_history *history, unsigned int depth ) {
 	unsigned int offset;

 	offset = ( ( history->next - depth ) %
 		   ( sizeof ( history->entries ) /
 		     sizeof ( history->entries[0] ) ) );
 	return &history->entries[offset];
 }

 /**
  * Read string from history buffer
  *
  * @v history		History buffer
  * @v depth		Depth within history buffer
  * @ret string		String
  */
 static const char * history_fetch ( struct readline_history *history,
 				    unsigned int depth ) {
 	struct readline_history_entry *entry;

 	/* Return the temporary copy if it exists, otherwise return
 	 * the persistent copy.
 	 */
 	entry = history_entry ( history, depth );
 	return ( entry->temp ? entry->temp : entry->string );
 }

 /**
  * Write temporary string copy to history buffer
  *
  * @v history		History buffer
  * @v depth		Depth within history buffer
  * @v string		String
  */
 static void history_store ( struct readline_history *history,
 			    unsigned int depth, const char *string ) {
 	struct readline_history_entry *entry;
 	char *temp;

 	/* Create temporary copy of string */
 	temp = strdup ( string );
 	if ( ! temp ) {
 		/* Just discard the string; there's nothing we can do */
 		DBGC ( history, "READLINE %p could not store string\n",
 		       history );
 		return;
 	}

 	/* Store temporary copy */
 	entry = history_entry ( history, depth );
 	free ( entry->temp );
 	entry->temp = temp;
 }

 /**
  * Move to new history depth
  *
  * @v history		History buffer
  * @v offset		Offset by which to change depth
  * @v old_string	String (possibly modified) at current depth
  * @ret new_string	String at new depth, or NULL for no movement
  */
 static const char * history_move ( struct readline_history *history,
 				   int offset, const char *old_string ) {
 	unsigned int new_depth = ( history->depth + offset );
 	const char * new_string = history_fetch ( history, new_depth );

 	/* Depth checks */
 	if ( new_depth > READLINE_HISTORY_MAX_DEPTH )
 		return NULL;
 	if ( ! new_string )
 		return NULL;

 	/* Store temporary copy of old string at current depth */
 	history_store ( history, history->depth, old_string );

 	/* Update depth */
 	history->depth = new_depth;

 	/* Return new string */
 	return new_string;
 }

 /**
  * Append new history entry
  *
  * @v history		History buffer
  * @v string		String
  */
 static void history_append ( struct readline_history *history,
 			     const char *string ) {
 	struct readline_history_entry *entry;

 	/* Store new entry */
 	entry = history_entry ( history, 0 );
 	assert ( entry->string == NULL );
 	entry->string = strdup ( string );
 	if ( ! entry->string ) {
 		/* Just discard the string; there's nothing we can do */
 		DBGC ( history, "READLINE %p could not append string\n",
 		       history );
 		return;
 	}

 	/* Increment history position */
 	history->next++;

 	/* Prepare empty "next" slot */
 	entry = history_entry ( history, 0 );
 	free ( entry->string );
 	entry->string = NULL;
 }

 /**
  * Clean up history after editing
  *
  * @v history		History buffer
  */
 static void history_cleanup ( struct readline_history *history ) {
 	struct readline_history_entry *entry;
 	unsigned int i;

 	/* Discard any temporary strings */
 	for ( i = 0 ; i < ( sizeof ( history->entries ) /
 			    sizeof ( history->entries[0] ) ) ; i++ ) {
 		entry = &history->entries[i];
 		free ( entry->temp );
 		entry->temp = NULL;
 	}

 	/* Reset depth */
 	history->depth = 0;

 	/* Sanity check */
 	entry = history_entry ( history, 0 );
 	assert ( entry->string == NULL );
 }

 /**
  * Free history buffer
  *
  * @v history		History buffer
  */
 void history_free ( struct readline_history *history ) {
 	struct readline_history_entry *entry;
 	unsigned int i;

 	/* Discard any temporary strings */
 	for ( i = 0 ; i < ( sizeof ( history->entries ) /
 			    sizeof ( history->entries[0] ) ) ; i++ ) {
 		entry = &history->entries[i];
 		assert ( entry->temp == NULL );
 		free ( entry->string );
 	}
 }

 /**
  * Read line from console (with history)
  *
  * @v prompt		Prompt string
  * @v prefill		Prefill string, or NULL for no prefill
  * @v history		History buffer, or NULL for no history
  * @v timeout		Timeout period, in ticks (0=indefinite)
  * @ret line		Line read from console (excluding terminating newline)
  * @ret rc		Return status code
  *
  * The returned line is allocated with malloc(); the caller must
  * eventually call free() to release the storage.
  */
 int readline_history ( const char *prompt, const char *prefill,
 		       struct readline_history *history, unsigned long timeout,
 		       char **line ) {
 	struct edit_string string;
 	char *buf;
 	int key;
 	int move_by;
 	const char *new_string;
 	int rc;

 	/* Avoid returning uninitialised data on error */
 	*line = NULL;

 	/* Display prompt, if applicable */
 	if ( prompt )
 		printf ( "%s", prompt );

 	/* Ensure cursor is visible */
 	printf ( "\033[?25h" );

 	/* Allocate buffer and initialise editable string */
 	buf = zalloc ( READLINE_MAX );
 	if ( ! buf ) {
 		rc = -ENOMEM;
 		goto done;
 	}
 	memset ( &string, 0, sizeof ( string ) );
 	init_editstring ( &string, buf, READLINE_MAX );

 	/* Prefill string, if applicable */
 	if ( prefill ) {
 		replace_string ( &string, prefill );
 		sync_console ( &string );
 	}

 	while ( 1 ) {

 		/* Get keypress */
 		key = getkey ( timeout );
 		if ( key < 0 ) {
 			rc = -ETIMEDOUT;
 			goto done;
 		}
 		timeout = 0;

 		/* Handle keypress */
 		key = edit_string ( &string, key );
 		sync_console ( &string );
 		move_by = 0;
 		switch ( key ) {
 		case CR:
 		case LF:
 			/* Shrink string (ignoring failures) */
 			*line = realloc ( buf,
 					  ( strlen ( buf ) + 1 /* NUL */ ) );
 			if ( ! *line )
 				*line = buf;
 			buf = NULL;
 			rc = 0;
 			goto done;
 		case CTRL_C:
 			rc = -ECANCELED;
 			goto done;
 		case KEY_UP:
 			move_by = 1;
 			break;
 		case KEY_DOWN:
 			move_by = -1;
 			break;
 		default:
 			/* Do nothing */
 			break;
 		}

 		/* Handle history movement, if applicable */
 		if ( move_by && history ) {
 			new_string = history_move ( history, move_by, buf );
 			if ( new_string ) {
 				replace_string ( &string, new_string );
 				sync_console ( &string );
 			}
 		}
 	}

  done:
 	putchar ( '\n' );
 	free ( buf );
 	if ( history ) {
 		if ( *line && (*line)[0] )
 			history_append ( history, *line );
 		history_cleanup ( history );
 	}
 	assert ( ( rc == 0 ) ^ ( *line == NULL ) );
 	return rc;
 }

 /**
  * Read line from console
  *
  * @v prompt		Prompt string
  * @ret line		Line read from console (excluding terminating newline)
  *
  * The returned line is allocated with malloc(); the caller must
  * eventually call free() to release the storage.
  */
 char * readline ( const char *prompt ) {
 	char *line;

 	readline_history ( prompt, NULL, NULL, 0, &line );
 	return line;
 }
	/*
	* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
	*
	* This program 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 2 of the
	* License, or any later version.
	*
	* This program 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, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	* 02110-1301, USA.
	*
	* You can also choose to distribute this program under the terms of
	* the Unmodified Binary Distribution Licence (as given in the file
	* COPYING.UBDL), provided that you have satisfied its requirements.
	*/

	FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

	#include <stdio.h>
	#include <string.h>
	#include <stdlib.h>
	#include <errno.h>
	#include <ipxe/console.h>
	#include <ipxe/keys.h>
	#include <ipxe/editstring.h>
	#include <readline/readline.h>

	/** @file
	*
	* Minimal readline
	*
	*/

	#define READLINE_MAX 1024

	/**
	* Synchronise console with edited string
	*
	* @v string Editable string
	*/
	static void sync_console ( struct edit_string *string ) {
	unsigned int mod_start = string->mod_start;
	unsigned int mod_end = string->mod_end;
	unsigned int cursor = string->last_cursor;
	size_t len = strlen ( string->buf );

	/* Expand region back to old cursor position if applicable */
	if ( mod_start > string->last_cursor )
	mod_start = string->last_cursor;

	/* Expand region forward to new cursor position if applicable */
	if ( mod_end < string->cursor )
	mod_end = string->cursor;

	/* Backspace to start of region */
	while ( cursor > mod_start ) {
	putchar ( '\b' );
	cursor--;
	}

	/* Print modified region */
	while ( cursor < mod_end ) {
	putchar ( ( cursor >= len ) ? ' ' : string->buf[cursor] );
	cursor++;
	}

	/* Backspace to new cursor position */
	while ( cursor > string->cursor ) {
	putchar ( '\b' );
	cursor--;
	}
	}

	/**
	* Locate history entry
	*
	* @v history History buffer
	* @v depth Depth within history buffer
	* @ret entry History entry
	*/
	static struct readline_history_entry *
	history_entry ( struct readline_history *history, unsigned int depth ) {
	unsigned int offset;

	offset = ( ( history->next - depth ) %
	( sizeof ( history->entries ) /
	sizeof ( history->entries[0] ) ) );
	return &history->entries[offset];
	}

	/**
	* Read string from history buffer
	*
	* @v history History buffer
	* @v depth Depth within history buffer
	* @ret string String
	*/
	static const char * history_fetch ( struct readline_history *history,
	unsigned int depth ) {
	struct readline_history_entry *entry;

	/* Return the temporary copy if it exists, otherwise return
	* the persistent copy.
	*/
	entry = history_entry ( history, depth );
	return ( entry->temp ? entry->temp : entry->string );
	}

	/**
	* Write temporary string copy to history buffer
	*
	* @v history History buffer
	* @v depth Depth within history buffer
	* @v string String
	*/
	static void history_store ( struct readline_history *history,
	unsigned int depth, const char *string ) {
	struct readline_history_entry *entry;
	char *temp;

	/* Create temporary copy of string */
	temp = strdup ( string );
	if ( ! temp ) {
	/* Just discard the string; there's nothing we can do */
	DBGC ( history, "READLINE %p could not store string\n",
	history );
	return;
	}

	/* Store temporary copy */
	entry = history_entry ( history, depth );
	free ( entry->temp );
	entry->temp = temp;
	}

	/**
	* Move to new history depth
	*
	* @v history History buffer
	* @v offset Offset by which to change depth
	* @v old_string String (possibly modified) at current depth
	* @ret new_string String at new depth, or NULL for no movement
	*/
	static const char * history_move ( struct readline_history *history,
	int offset, const char *old_string ) {
	unsigned int new_depth = ( history->depth + offset );
	const char * new_string = history_fetch ( history, new_depth );

	/* Depth checks */
	if ( new_depth > READLINE_HISTORY_MAX_DEPTH )
	return NULL;
	if ( ! new_string )
	return NULL;

	/* Store temporary copy of old string at current depth */
	history_store ( history, history->depth, old_string );

	/* Update depth */
	history->depth = new_depth;

	/* Return new string */
	return new_string;
	}

	/**
	* Append new history entry
	*
	* @v history History buffer
	* @v string String
	*/
	static void history_append ( struct readline_history *history,
	const char *string ) {
	struct readline_history_entry *entry;

	/* Store new entry */
	entry = history_entry ( history, 0 );
	assert ( entry->string == NULL );
	entry->string = strdup ( string );
	if ( ! entry->string ) {
	/* Just discard the string; there's nothing we can do */
	DBGC ( history, "READLINE %p could not append string\n",
	history );
	return;
	}

	/* Increment history position */
	history->next++;

	/* Prepare empty "next" slot */
	entry = history_entry ( history, 0 );
	free ( entry->string );
	entry->string = NULL;
	}

	/**
	* Clean up history after editing
	*
	* @v history History buffer
	*/
	static void history_cleanup ( struct readline_history *history ) {
	struct readline_history_entry *entry;
	unsigned int i;

	/* Discard any temporary strings */
	for ( i = 0 ; i < ( sizeof ( history->entries ) /
	sizeof ( history->entries[0] ) ) ; i++ ) {
	entry = &history->entries[i];
	free ( entry->temp );
	entry->temp = NULL;
	}

	/* Reset depth */
	history->depth = 0;

	/* Sanity check */
	entry = history_entry ( history, 0 );
	assert ( entry->string == NULL );
	}

	/**
	* Free history buffer
	*
	* @v history History buffer
	*/
	void history_free ( struct readline_history *history ) {
	struct readline_history_entry *entry;
	unsigned int i;

	/* Discard any temporary strings */
	for ( i = 0 ; i < ( sizeof ( history->entries ) /
	sizeof ( history->entries[0] ) ) ; i++ ) {
	entry = &history->entries[i];
	assert ( entry->temp == NULL );
	free ( entry->string );
	}
	}

	/**
	* Read line from console (with history)
	*
	* @v prompt Prompt string
	* @v prefill Prefill string, or NULL for no prefill
	* @v history History buffer, or NULL for no history
	* @v timeout Timeout period, in ticks (0=indefinite)
	* @ret line Line read from console (excluding terminating newline)
	* @ret rc Return status code
	*
	* The returned line is allocated with malloc(); the caller must
	* eventually call free() to release the storage.
	*/
	int readline_history ( const char prompt, const char prefill,
	struct readline_history *history, unsigned long timeout,
	char **line ) {
	struct edit_string string;
	char *buf;
	int key;
	int move_by;
	const char *new_string;
	int rc;

	/* Avoid returning uninitialised data on error */
	*line = NULL;

	/* Display prompt, if applicable */
	if ( prompt )
	printf ( "%s", prompt );

	/* Ensure cursor is visible */
	printf ( "\033[?25h" );

	/* Allocate buffer and initialise editable string */
	buf = zalloc ( READLINE_MAX );
	if ( ! buf ) {
	rc = -ENOMEM;
	goto done;
	}
	memset ( &string, 0, sizeof ( string ) );
	init_editstring ( &string, buf, READLINE_MAX );

	/* Prefill string, if applicable */
	if ( prefill ) {
	replace_string ( &string, prefill );
	sync_console ( &string );
	}

	while ( 1 ) {

	/* Get keypress */
	key = getkey ( timeout );
	if ( key < 0 ) {
	rc = -ETIMEDOUT;
	goto done;
	}
	timeout = 0;

	/* Handle keypress */
	key = edit_string ( &string, key );
	sync_console ( &string );
	move_by = 0;
	switch ( key ) {
	case CR:
	case LF:
	/* Shrink string (ignoring failures) */
	*line = realloc ( buf,
	( strlen ( buf ) + 1 /* NUL */ ) );
	if ( ! *line )
	*line = buf;
	buf = NULL;
	rc = 0;
	goto done;
	case CTRL_C:
	rc = -ECANCELED;
	goto done;
	case KEY_UP:
	move_by = 1;
	break;
	case KEY_DOWN:
	move_by = -1;
	break;
	default:
	/* Do nothing */
	break;
	}

	/* Handle history movement, if applicable */
	if ( move_by && history ) {
	new_string = history_move ( history, move_by, buf );
	if ( new_string ) {
	replace_string ( &string, new_string );
	sync_console ( &string );
	}
	}
	}

	done:
	putchar ( '\n' );
	free ( buf );
	if ( history ) {
	if ( line && (line)[0] )
	history_append ( history, *line );
	history_cleanup ( history );
	}
	assert ( ( rc == 0 ) ^ ( *line == NULL ) );
	return rc;
	}

	/**
	* Read line from console
	*
	* @v prompt Prompt string
	* @ret line Line read from console (excluding terminating newline)
	*
	* The returned line is allocated with malloc(); the caller must
	* eventually call free() to release the storage.
	*/
	char * readline ( const char *prompt ) {
	char *line;

	readline_history ( prompt, NULL, NULL, 0, &line );
	return line;
	}