readline.h File Reference

Minmal readline. More...

Go to the source code of this file.

Data Structures
struct	readline_history_entry
	A readline history entry. More...
struct	readline_history
	A readline history buffer. More...

Macros
#define	READLINE_HISTORY_MAX_DEPTH   ( ( 1 << 3 ) - 1 )
	Maximum depth of a readline history buffer. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
void	history_free (struct readline_history *history)
	Free history buffer. More...
int	readline_history (const char *prompt, const char *prefill, struct readline_history *history, unsigned long timeout, char **line)
	Read line from console (with history) More...
char *__malloc	readline (const char *prompt)
	Read line from console. More...

Detailed Description

Minmal readline.

Definition in file readline.h.

Macro Definition Documentation

READLINE_HISTORY_MAX_DEPTH

#define READLINE_HISTORY_MAX_DEPTH   ( ( 1 << 3 ) - 1 )

Maximum depth of a readline history buffer.

Must be one less than a power of two.

Definition at line 28 of file readline.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

history_free()

void history_free

(

struct readline_history *

history

)

Free history buffer.

Parameters

history

History buffer

Definition at line 232 of file readline.c.

                                                       {
        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 );
        }
}

References assert(), readline_history::entries, entry, free, and NULL.

Referenced by shell().

readline_history()

int readline_history	(	const char *	prompt,
		const char *	prefill,
		struct readline_history *	history,
		unsigned long	timeout,
		char **	line
	)

Read line from console (with history)

Parameters

prompt	Prompt string
prefill	Prefill string, or NULL for no prefill
history	History buffer, or NULL for no history
timeout	Timeout period, in ticks (0=indefinite)

Return values

line	Line read from console (excluding terminating newline)
rc	Return status code

The returned line is allocated with malloc(); the caller must eventually call free() to release the storage.

Definition at line 258 of file readline.c.

                                     {
        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;
}

References assert(), edit_string::buf, CR, CTRL_C, done, ECANCELED, edit_string(), ENOMEM, ETIMEDOUT, free, getkey(), history_append(), history_cleanup(), history_move(), init_editstring(), key, KEY_DOWN, KEY_UP, LF, memset(), NULL, printf(), prompt(), putchar(), rc, READLINE_MAX, realloc(), replace_string(), string, strlen(), sync_console(), timeout(), and zalloc().

Referenced by readline(), and shell().

readline()

char* __malloc 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 363 of file readline.c.

                                       {
        char *line;

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

References NULL, prompt(), and readline_history().