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Annotation of src/usr.bin/less/brac.c, Revision 1.7

1.1       etheisen    1: /*
1.6       shadchin    2:  * Copyright (C) 1984-2012  Mark Nudelman
1.1       etheisen    3:  *
1.4       millert     4:  * You may distribute under the terms of either the GNU General Public
                      5:  * License or the Less License, as specified in the README file.
1.1       etheisen    6:  *
1.6       shadchin    7:  * For more information, see the README file.
1.1       etheisen    8:  */
1.7     ! nicm        9: /*
        !            10:  * Modified for use with illumos.
        !            11:  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
        !            12:  */
1.1       etheisen   13:
                     14: /*
                     15:  * Routines to perform bracket matching functions.
                     16:  */
                     17:
                     18: #include "less.h"
                     19: #include "position.h"
                     20:
                     21: /*
1.7     ! nicm       22:  * Try to match the n-th open bracket
1.1       etheisen   23:  *  which appears in the top displayed line (forwdir),
1.7     ! nicm       24:  * or the n-th close bracket
1.1       etheisen   25:  *  which appears in the bottom displayed line (!forwdir).
1.7     ! nicm       26:  * The characters which serve as "open bracket" and
1.1       etheisen   27:  * "close bracket" are given.
                     28:  */
1.7     ! nicm       29: void
        !            30: match_brac(int obrac, int cbrac, int forwdir, int n)
1.1       etheisen   31: {
1.7     ! nicm       32:        int c;
        !            33:        int nest;
        !            34:        off_t pos;
        !            35:        int (*chget)(void);
1.1       etheisen   36:
                     37:        /*
                     38:         * Seek to the line containing the open bracket.
                     39:         * This is either the top or bottom line on the screen,
                     40:         * depending on the type of bracket.
                     41:         */
                     42:        pos = position((forwdir) ? TOP : BOTTOM);
1.7     ! nicm       43:        if (pos == -1 || ch_seek(pos)) {
1.1       etheisen   44:                if (forwdir)
                     45:                        error("Nothing in top line", NULL_PARG);
                     46:                else
                     47:                        error("Nothing in bottom line", NULL_PARG);
                     48:                return;
                     49:        }
                     50:
                     51:        /*
                     52:         * Look thru the line to find the open bracket to match.
                     53:         */
1.7     ! nicm       54:        do {
        !            55:                if ((c = ch_forw_get()) == '\n' || c == EOI) {
1.1       etheisen   56:                        if (forwdir)
                     57:                                error("No bracket in top line", NULL_PARG);
                     58:                        else
                     59:                                error("No bracket in bottom line", NULL_PARG);
                     60:                        return;
                     61:                }
                     62:        } while (c != obrac || --n > 0);
                     63:
                     64:        /*
                     65:         * Position the file just "after" the open bracket
                     66:         * (in the direction in which we will be searching).
                     67:         * If searching forward, we are already after the bracket.
                     68:         * If searching backward, skip back over the open bracket.
                     69:         */
                     70:        if (!forwdir)
                     71:                (void) ch_back_get();
                     72:
                     73:        /*
                     74:         * Search the file for the matching bracket.
                     75:         */
                     76:        chget = (forwdir) ? ch_forw_get : ch_back_get;
                     77:        nest = 0;
1.7     ! nicm       78:        while ((c = (*chget)()) != EOI) {
        !            79:                if (c == obrac) {
1.1       etheisen   80:                        nest++;
1.7     ! nicm       81:                } else if (c == cbrac && --nest < 0) {
1.1       etheisen   82:                        /*
                     83:                         * Found the matching bracket.
                     84:                         * If searching backward, put it on the top line.
                     85:                         * If searching forward, put it on the bottom line.
                     86:                         */
                     87:                        jump_line_loc(ch_tell(), forwdir ? -1 : 1);
                     88:                        return;
                     89:                }
                     90:        }
                     91:        error("No matching bracket", NULL_PARG);
                     92: }