readline.c File Reference

Minimal readline. More...

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

Go to the source code of this file.

Defines
#define	READLINE_MAX   256
Functions
	FILE_LICENCE (GPL2_OR_LATER)
static void	sync_console (struct edit_string *string)
	Synchronise console with edited string.
char *	readline (const char *prompt)
	Read line from console.

---

Detailed Description

Minimal readline.

Definition in file readline.c.

---

Define Documentation

#define READLINE_MAX   256

Definition at line 35 of file readline.c.

Referenced by readline().

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

static void sync_console

(

struct edit_string *

string

)

[static]

Synchronise console with edited string.

Parameters:

string

Editable string

Definition at line 44 of file readline.c.

References edit_string::buf, edit_string::cursor, edit_string::last_cursor, putchar(), and strlen().

Referenced by readline().

                                                        {
        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--;
        }
}

char* readline

(

const char *

prompt

)

Read line from console.

Parameters:

prompt

Prompt string

Return values:

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.

Definition at line 86 of file readline.c.

References CR, CTRL_C, edit_string(), getkey(), LF, memset(), NULL, printf(), putchar(), READLINE_MAX, strdup(), and sync_console().

Referenced by shell().

                                       {
        char buf[READLINE_MAX];
        struct edit_string string;
        int key;
        char *line;

        if ( prompt )
                printf ( "%s", prompt );

        memset ( &string, 0, sizeof ( string ) );
        string.buf = buf;
        string.len = sizeof ( buf );
        buf[0] = '\0';

        while ( 1 ) {
                key = edit_string ( &string, getkey() );
                sync_console ( &string );
                switch ( key ) {
                case CR:
                case LF:
                        putchar ( '\n' );
                        line = strdup ( buf );
                        if ( ! line )
                                printf ( "Out of memory\n" );
                        return line;
                case CTRL_C:
                        putchar ( '\n' );
                        return NULL;
                default:
                        /* Do nothing */
                        break;
                }
        }
}