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Annotation of qemu/roms/ipxe/src/hci/readline.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (C) 2006 Michael Brown <[email protected]>.
        !             3:  *
        !             4:  * This program is free software; you can redistribute it and/or
        !             5:  * modify it under the terms of the GNU General Public License as
        !             6:  * published by the Free Software Foundation; either version 2 of the
        !             7:  * License, or any later version.
        !             8:  *
        !             9:  * This program is distributed in the hope that it will be useful, but
        !            10:  * WITHOUT ANY WARRANTY; without even the implied warranty of
        !            11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
        !            12:  * General Public License for more details.
        !            13:  *
        !            14:  * You should have received a copy of the GNU General Public License
        !            15:  * along with this program; if not, write to the Free Software
        !            16:  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
        !            17:  */
        !            18: 
        !            19: FILE_LICENCE ( GPL2_OR_LATER );
        !            20: 
        !            21: #include <stdio.h>
        !            22: #include <string.h>
        !            23: #include <stdlib.h>
        !            24: #include <ipxe/console.h>
        !            25: #include <ipxe/keys.h>
        !            26: #include <ipxe/editstring.h>
        !            27: #include <readline/readline.h>
        !            28: 
        !            29: /** @file
        !            30:  *
        !            31:  * Minimal readline
        !            32:  *
        !            33:  */
        !            34: 
        !            35: #define READLINE_MAX 256
        !            36: 
        !            37: /**
        !            38:  * Synchronise console with edited string
        !            39:  *
        !            40:  * @v string           Editable string
        !            41:  */
        !            42: static void sync_console ( struct edit_string *string ) {
        !            43:        unsigned int mod_start = string->mod_start;
        !            44:        unsigned int mod_end = string->mod_end;
        !            45:        unsigned int cursor = string->last_cursor;
        !            46:        size_t len = strlen ( string->buf );
        !            47: 
        !            48:        /* Expand region back to old cursor position if applicable */
        !            49:        if ( mod_start > string->last_cursor )
        !            50:                mod_start = string->last_cursor;
        !            51: 
        !            52:        /* Expand region forward to new cursor position if applicable */
        !            53:        if ( mod_end < string->cursor )
        !            54:                mod_end = string->cursor;
        !            55: 
        !            56:        /* Backspace to start of region */
        !            57:        while ( cursor > mod_start ) {
        !            58:                putchar ( '\b' );
        !            59:                cursor--;
        !            60:        }
        !            61: 
        !            62:        /* Print modified region */
        !            63:        while ( cursor < mod_end ) {
        !            64:                putchar ( ( cursor >= len ) ? ' ' : string->buf[cursor] );
        !            65:                cursor++;
        !            66:        }
        !            67: 
        !            68:        /* Backspace to new cursor position */
        !            69:        while ( cursor > string->cursor ) {
        !            70:                putchar ( '\b' );
        !            71:                cursor--;
        !            72:        }
        !            73: }
        !            74: 
        !            75: /**
        !            76:  * Locate history entry
        !            77:  *
        !            78:  * @v history          History buffer
        !            79:  * @v depth            Depth within history buffer
        !            80:  * @ret entry          History entry
        !            81:  */
        !            82: static struct readline_history_entry *
        !            83: history_entry ( struct readline_history *history, unsigned int depth ) {
        !            84:        unsigned int offset;
        !            85: 
        !            86:        offset = ( ( history->next - depth ) %
        !            87:                   ( sizeof ( history->entries ) /
        !            88:                     sizeof ( history->entries[0] ) ) );
        !            89:        return &history->entries[offset];
        !            90: }
        !            91: 
        !            92: /**
        !            93:  * Read string from history buffer
        !            94:  *
        !            95:  * @v history          History buffer
        !            96:  * @v depth            Depth within history buffer
        !            97:  * @ret string         String
        !            98:  */
        !            99: static const char * history_fetch ( struct readline_history *history,
        !           100:                                    unsigned int depth ) {
        !           101:        struct readline_history_entry *entry;
        !           102: 
        !           103:        /* Return the temporary copy if it exists, otherwise return
        !           104:         * the persistent copy.
        !           105:         */
        !           106:        entry = history_entry ( history, depth );
        !           107:        return ( entry->temp ? entry->temp : entry->string );
        !           108: }
        !           109: 
        !           110: /**
        !           111:  * Write temporary string copy to history buffer
        !           112:  *
        !           113:  * @v history          History buffer
        !           114:  * @v depth            Depth within history buffer
        !           115:  * @v string           String
        !           116:  */
        !           117: static void history_store ( struct readline_history *history,
        !           118:                            unsigned int depth, const char *string ) {
        !           119:        struct readline_history_entry *entry;
        !           120:        char *temp;
        !           121: 
        !           122:        /* Create temporary copy of string */
        !           123:        temp = strdup ( string );
        !           124:        if ( ! temp ) {
        !           125:                /* Just discard the string; there's nothing we can do */
        !           126:                DBGC ( history, "READLINE %p could not store string\n",
        !           127:                       history );
        !           128:                return;
        !           129:        }
        !           130: 
        !           131:        /* Store temporary copy */
        !           132:        entry = history_entry ( history, depth );
        !           133:        free ( entry->temp );
        !           134:        entry->temp = temp;
        !           135: }
        !           136: 
        !           137: /**
        !           138:  * Move to new history depth
        !           139:  *
        !           140:  * @v history          History buffer
        !           141:  * @v offset           Offset by which to change depth
        !           142:  * @v old_string       String (possibly modified) at current depth
        !           143:  * @ret new_string     String at new depth, or NULL for no movement
        !           144:  */
        !           145: static const char * history_move ( struct readline_history *history,
        !           146:                                   int offset, const char *old_string ) {
        !           147:        unsigned int new_depth = ( history->depth + offset );
        !           148:        const char * new_string = history_fetch ( history, new_depth );
        !           149: 
        !           150:        /* Depth checks */
        !           151:        if ( new_depth > READLINE_HISTORY_MAX_DEPTH )
        !           152:                return NULL;
        !           153:        if ( ! new_string )
        !           154:                return NULL;
        !           155: 
        !           156:        /* Store temporary copy of old string at current depth */
        !           157:        history_store ( history, history->depth, old_string );
        !           158: 
        !           159:        /* Update depth */
        !           160:        history->depth = new_depth;
        !           161: 
        !           162:        /* Return new string */
        !           163:        return new_string;
        !           164: }
        !           165: 
        !           166: /**
        !           167:  * Append new history entry
        !           168:  *
        !           169:  * @v history          History buffer
        !           170:  * @v string           String
        !           171:  */
        !           172: static void history_append ( struct readline_history *history,
        !           173:                             const char *string ) {
        !           174:        struct readline_history_entry *entry;
        !           175: 
        !           176:        /* Store new entry */
        !           177:        entry = history_entry ( history, 0 );
        !           178:        assert ( entry->string == NULL );
        !           179:        entry->string = strdup ( string );
        !           180:        if ( ! entry->string ) {
        !           181:                /* Just discard the string; there's nothing we can do */
        !           182:                DBGC ( history, "READLINE %p could not append string\n",
        !           183:                       history );
        !           184:                return;
        !           185:        }
        !           186: 
        !           187:        /* Increment history position */
        !           188:        history->next++;
        !           189: 
        !           190:        /* Prepare empty "next" slot */
        !           191:        entry = history_entry ( history, 0 );
        !           192:        free ( entry->string );
        !           193:        entry->string = NULL;
        !           194: }
        !           195: 
        !           196: /**
        !           197:  * Clean up history after editing
        !           198:  *
        !           199:  * @v history          History buffer
        !           200:  */
        !           201: static void history_cleanup ( struct readline_history *history ) {
        !           202:        struct readline_history_entry *entry;
        !           203:        unsigned int i;
        !           204: 
        !           205:        /* Discard any temporary strings */
        !           206:        for ( i = 0 ; i < ( sizeof ( history->entries ) /
        !           207:                            sizeof ( history->entries[0] ) ) ; i++ ) {
        !           208:                entry = &history->entries[i];
        !           209:                free ( entry->temp );
        !           210:                entry->temp = NULL;
        !           211:        }
        !           212: 
        !           213:        /* Reset depth */
        !           214:        history->depth = 0;
        !           215: 
        !           216:        /* Sanity check */
        !           217:        entry = history_entry ( history, 0 );
        !           218:        assert ( entry->string == NULL );
        !           219: }
        !           220: 
        !           221: /**
        !           222:  * Free history buffer
        !           223:  *
        !           224:  * @v history          History buffer
        !           225:  */
        !           226: void history_free ( struct readline_history *history ) {
        !           227:        struct readline_history_entry *entry;
        !           228:        unsigned int i;
        !           229: 
        !           230:        /* Discard any temporary strings */
        !           231:        for ( i = 0 ; i < ( sizeof ( history->entries ) /
        !           232:                            sizeof ( history->entries[0] ) ) ; i++ ) {
        !           233:                entry = &history->entries[i];
        !           234:                assert ( entry->temp == NULL );
        !           235:                free ( entry->string );
        !           236:        }
        !           237: }
        !           238: 
        !           239: /**
        !           240:  * Read line from console (with history)
        !           241:  *
        !           242:  * @v prompt           Prompt string
        !           243:  * @v history          History buffer, or NULL for no history
        !           244:  * @ret line           Line read from console (excluding terminating newline)
        !           245:  *
        !           246:  * The returned line is allocated with malloc(); the caller must
        !           247:  * eventually call free() to release the storage.
        !           248:  */
        !           249: char * readline_history ( const char *prompt,
        !           250:                          struct readline_history *history ) {
        !           251:        char buf[READLINE_MAX];
        !           252:        struct edit_string string;
        !           253:        int key;
        !           254:        int move_by;
        !           255:        const char *new_string;
        !           256:        char *line;
        !           257: 
        !           258:        /* Display prompt, if applicable */
        !           259:        if ( prompt )
        !           260:                printf ( "%s", prompt );
        !           261: 
        !           262:        /* Initialise editable string */
        !           263:        memset ( &string, 0, sizeof ( string ) );
        !           264:        init_editstring ( &string, buf, sizeof ( buf ) );
        !           265:        buf[0] = '\0';
        !           266: 
        !           267:        while ( 1 ) {
        !           268:                /* Handle keypress */
        !           269:                key = edit_string ( &string, getkey ( 0 ) );
        !           270:                sync_console ( &string );
        !           271:                move_by = 0;
        !           272:                switch ( key ) {
        !           273:                case CR:
        !           274:                case LF:
        !           275:                        line = strdup ( buf );
        !           276:                        if ( ! line )
        !           277:                                printf ( "\nOut of memory" );
        !           278:                        goto done;
        !           279:                case CTRL_C:
        !           280:                        line = NULL;
        !           281:                        goto done;
        !           282:                case KEY_UP:
        !           283:                        move_by = 1;
        !           284:                        break;
        !           285:                case KEY_DOWN:
        !           286:                        move_by = -1;
        !           287:                        break;
        !           288:                default:
        !           289:                        /* Do nothing */
        !           290:                        break;
        !           291:                }
        !           292: 
        !           293:                /* Handle history movement, if applicable */
        !           294:                if ( move_by && history ) {
        !           295:                        new_string = history_move ( history, move_by, buf );
        !           296:                        if ( new_string ) {
        !           297:                                replace_string ( &string, new_string );
        !           298:                                sync_console ( &string );
        !           299:                        }
        !           300:                }
        !           301:        }
        !           302: 
        !           303:  done:
        !           304:        putchar ( '\n' );
        !           305:        if ( history ) {
        !           306:                if ( line && line[0] )
        !           307:                        history_append ( history, line );
        !           308:                history_cleanup ( history );
        !           309:        }
        !           310:        return line;
        !           311: }
        !           312: 
        !           313: /**
        !           314:  * Read line from console
        !           315:  *
        !           316:  * @v prompt           Prompt string
        !           317:  * @ret line           Line read from console (excluding terminating newline)
        !           318:  *
        !           319:  * The returned line is allocated with malloc(); the caller must
        !           320:  * eventually call free() to release the storage.
        !           321:  */
        !           322: char * readline ( const char *prompt ) {
        !           323:        return readline_history ( prompt, NULL );
        !           324: }

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