editstring.c File Reference

Editable strings. More...

#include <assert.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <ipxe/keys.h>
#include <ipxe/editstring.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static	__attribute__ ((nonnull(1)))
static int	insert_character (struct edit_string *string, unsigned int character)
	Insert character at current cursor position. More...
static void	delete_character (struct edit_string *string)
	Delete character at current cursor position. More...
static void	backspace (struct edit_string *string)
	Delete character to left of current cursor position. More...
static void	previous_word (struct edit_string *string)
	Move to start of previous word. More...
static void	kill_word (struct edit_string *string)
	Delete to end of previous word. More...
static void	kill_sol (struct edit_string *string)
	Delete to start of line. More...
static void	kill_eol (struct edit_string *string)
	Delete to end of line. More...
int	replace_string (struct edit_string *string, const char *replacement)
	Replace editable string. More...
int	edit_string (struct edit_string *string, int key)
	Edit editable string. More...

Detailed Description

Editable strings.

Definition in file editstring.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

__attribute__()

static __attribute__ ( (nonnull(1))  )

static

Definition at line 40 of file editstring.c.

                                                     {
        size_t old_len, max_delete_len, move_len, insert_len, new_len;
        char *buf;
        char *tmp;

        /* Prepare edit history */
        string->mod_start = string->cursor;
        string->mod_end = string->cursor;

        /* Calculate lengths */
        buf = *(string->buf);
        old_len = ( buf ? strlen ( buf ) : 0 );
        assert ( string->cursor <= old_len );
        max_delete_len = ( old_len - string->cursor );
        if ( delete_len > max_delete_len )
                delete_len = max_delete_len;
        move_len = ( max_delete_len - delete_len );
        insert_len = ( insert_text ? strlen ( insert_text ) : 0 );
        new_len = ( old_len - delete_len + insert_len );

        /* Delete existing text */
        memmove ( ( buf + string->cursor ),
                  ( buf + string->cursor + delete_len ), move_len );

        /* Reallocate string, ignoring failures if shrinking */
        tmp = realloc ( buf, ( new_len + 1 /* NUL */ ) );
        if ( tmp ) {
                buf = tmp;
                *(string->buf) = buf;
        } else if ( ( new_len > old_len ) || ( ! buf ) ) {
                return -ENOMEM;
        }

        /* Create space for inserted text */
        memmove ( ( buf + string->cursor + insert_len ),
                  ( buf + string->cursor ), move_len );

        /* Copy inserted text to cursor position */
        memcpy ( ( buf + string->cursor ), insert_text, insert_len );
        string->cursor += insert_len;

        /* Terminate string */
        buf[new_len] = '\0';

        /* Update edit history */
        string->mod_end = ( ( new_len > old_len ) ? new_len : old_len );

        return 0;
}

References assert(), ENOMEM, memcpy(), memmove(), realloc(), string, strlen(), and tmp.

insert_character()

static int insert_character ( struct edit_string *  string, unsigned int  character  )

static

Insert character at current cursor position.

Parameters

string	Editable string
character	Character to insert

Return values

rc	Return status code

Definition at line 118 of file editstring.c.

                                                       {
        char insert_text[2] = { character, '\0' };

        return insert_delete ( string, 0, insert_text );
}

Referenced by edit_string().

delete_character()

static void delete_character ( struct edit_string *  string )

static

Delete character at current cursor position.

Parameters

string

Editable string

Definition at line 130 of file editstring.c.

                                                            {
        int rc;

        rc = insert_delete ( string, 1, NULL );
        assert ( ( rc == 0 ) || ( *(string->buf) == NULL ) );
}

References assert(), NULL, rc, and string.

Referenced by backspace(), and edit_string().

backspace()

static void backspace ( struct edit_string *  string )

static

Delete character to left of current cursor position.

Parameters

string

Editable string

Definition at line 142 of file editstring.c.

                                                     {

        if ( string->cursor > 0 ) {
                string->cursor--;
                delete_character ( string );
        }
}

References delete_character(), and string.

Referenced by edit_string().

previous_word()

static void previous_word ( struct edit_string *  string )

static

Move to start of previous word.

Parameters

string

Editable string

Definition at line 155 of file editstring.c.

                                                         {
        const char *buf = *(string->buf);
        size_t cursor = string->cursor;

        while ( cursor && isspace ( buf[ cursor - 1 ] ) ) {
                cursor--;
        }
        while ( cursor && ( ! isspace ( buf[ cursor - 1 ] ) ) ) {
                cursor--;
        }
        string->cursor = cursor;
}

References isspace().

Referenced by kill_word().

kill_word()

static void kill_word ( struct edit_string *  string )

static

Delete to end of previous word.

Parameters

string

Editable string

Definition at line 173 of file editstring.c.

                                                     {
        size_t old_cursor = string->cursor;
        int rc;

        previous_word ( string );
        rc = insert_delete ( string, ( old_cursor - string->cursor ), NULL );
        assert ( ( rc == 0 ) || ( *(string->buf) == NULL ) );
}

References assert(), NULL, previous_word(), rc, and string.

Referenced by edit_string().

kill_sol()

static void kill_sol ( struct edit_string *  string )

static

Delete to start of line.

Parameters

string

Editable string

Definition at line 187 of file editstring.c.

                                                    {
        size_t old_cursor = string->cursor;
        int rc;

        string->cursor = 0;
        rc = insert_delete ( string, old_cursor, NULL );
        assert ( ( rc == 0 ) || ( *(string->buf) == NULL ) );
}

References assert(), NULL, rc, and string.

Referenced by edit_string().

kill_eol()

static void kill_eol ( struct edit_string *  string )

static

Delete to end of line.

Parameters

string

Editable string

Definition at line 201 of file editstring.c.

                                                    {
        int rc;

        rc = insert_delete ( string, ~( ( size_t ) 0 ), NULL );
        assert ( ( rc == 0 ) || ( *(string->buf) == NULL ) );
}

References assert(), NULL, rc, and string.

Referenced by edit_string().

replace_string()

int replace_string	(	struct edit_string *	string,
		const char *	replacement
	)

Replace editable string.

Parameters

string	Editable string
replacement	Replacement string, or NULL to empty the string

Return values

rc	Return status code

Replace the entire content of the editable string and update the edit history to allow the caller to bring the display into sync with the string content.

This function does not itself update the display in any way.

Upon success, the string buffer is guaranteed to be non-NULL (even if the replacement string is NULL or empty).

Errors may safely be ignored if it is deemed that subsequently failing to update the display will provide sufficient feedback to the user.

Definition at line 228 of file editstring.c.

                                                                           {

        string->cursor = 0;
        return insert_delete ( string, ~( ( size_t ) 0 ), replacement );
}

References replacement.

Referenced by editstring_okx(), and readline_history().

edit_string()

int edit_string	(	struct edit_string *	string,
		int	key
	)

Edit editable string.

Parameters

string	Editable string
key	Key pressed by user

Return values

key	Key returned to application, zero, or negative error

Handles keypresses and updates the content of the editable string. Basic line editing facilities (delete/insert/cursor) are supported. If edit_string() understands and uses the keypress it will return zero, otherwise it will return the original key.

The string's edit history will be updated to allow the caller to efficiently bring the display into sync with the string content.

This function does not itself update the display in any way.

Errors may safely be ignored if it is deemed that subsequently failing to update the display will provide sufficient feedback to the user.

Definition at line 255 of file editstring.c.

                                                        {
        const char *buf = *(string->buf);
        size_t len = ( buf ? strlen ( buf ) : 0 );
        int retval = 0;

        /* Prepare edit history */
        string->last_cursor = string->cursor;
        string->mod_start = string->cursor;
        string->mod_end = string->cursor;

        /* Interpret key */
        if ( ( key >= 0x20 ) && ( key <= 0x7e ) ) {
                /* Printable character; insert at current position */
                retval = insert_character ( string, key );
        } else switch ( key ) {
        case KEY_BACKSPACE:
                /* Backspace */
                backspace ( string );
                break;
        case KEY_DC:
        case CTRL_D:
                /* Delete character */
                delete_character ( string );
                break;
        case CTRL_W:
                /* Delete word */
                kill_word ( string );
                break;
        case CTRL_U:
                /* Delete to start of line */
                kill_sol ( string );
                break;
        case CTRL_K:
                /* Delete to end of line */
                kill_eol ( string );
                break;
        case KEY_HOME:
        case CTRL_A:
                /* Start of line */
                string->cursor = 0;
                break;
        case KEY_END:
        case CTRL_E:
                /* End of line */
                string->cursor = len;
                break;
        case KEY_LEFT:
        case CTRL_B:
                /* Cursor left */
                if ( string->cursor > 0 )
                        string->cursor--;
                break;
        case KEY_RIGHT:
        case CTRL_F:
                /* Cursor right */
                if ( string->cursor < len )
                        string->cursor++;
                break;
        default:
                retval = key;
                break;
        }

        return retval;
}

References backspace(), CTRL_A, CTRL_B, CTRL_D, CTRL_E, CTRL_F, CTRL_K, CTRL_U, CTRL_W, delete_character(), insert_character(), key, KEY_BACKSPACE, KEY_DC, KEY_END, KEY_HOME, KEY_LEFT, KEY_RIGHT, kill_eol(), kill_sol(), kill_word(), len, retval, string, and strlen().

Referenced by edit_editbox(), and readline_history().