source: trunk/minix/commands/elvis/misc.c@ 21

/* misc.c */

/* Author:
 *      Steve Kirkendall
 *      14407 SW Teal Blvd. #C
 *      Beaverton, OR 97005
 *      kirkenda@cs.pdx.edu
 */


/* This file contains functions which didn't seem happy anywhere else */

#include "config.h"
#include "vi.h"


/* find a particular line & return a pointer to a copy of its text */
char *fetchline(line)
        long    line;   /* line number of the line to fetch */
{
        int             i;
        REG char        *scan;  /* used to search for the line in a BLK */
        long            l;      /* line number counter */
        static BLK      buf;    /* holds ONLY the selected line (as string) */
        REG char        *cpy;   /* used while copying the line */
        static long     nextline;       /* }  These four variables are used */
        static long     chglevel;       /*  } to implement a shortcut when  */
        static char     *nextscan;      /*  } consecutive lines are fetched */
        static long     nextlnum;       /* }                                */

        /* can we do a shortcut? */
        if (changes == chglevel && line == nextline)
        {
                scan = nextscan;
        }
        else
        {
                /* scan lnum[] to determine which block its in */
                for (i = 1; line > lnum[i]; i++)
                {
                }
                nextlnum = lnum[i];

                /* fetch text of the block containing that line */
                scan = blkget(i)->c;

                /* find the line in the block */
                for (l = lnum[i - 1]; ++l < line; )
                {
                        while (*scan++ != '\n')
                        {
                        }
                }
        }

        /* copy it into a block by itself, with no newline */
        for (cpy = buf.c; *scan != '\n'; )
        {
                *cpy++ = *scan++;
        }
        *cpy = '\0';

        /* maybe speed up the next call to fetchline() ? */
        if (line < nextlnum)
        {
                nextline = line + 1;
                chglevel = changes;
                nextscan = scan + 1;
        }
        else
        {
                nextline = 0;
        }

        /* Calls to fetchline() interfere with calls to pfetch().  Make sure
         * that pfetch() resets itself on its next invocation.
         */
        pchgs = 0L;

        /* Return a pointer to the line's text */
        return buf.c;
}


/* error message from the regexp code */
void regerror(txt)
        char    *txt;   /* an error message */
{
        msg("RE error: %s", txt);
}

/* This function is equivelent to the pfetch() macro */
void    pfetch(l)
        long    l;      /* line number of line to fetch */
{
        if(l != pline || changes != pchgs)
        {
                pline = (l);
                ptext = fetchline(pline);
                plen = strlen(ptext);
                pchgs = changes;
        }
}