commands/elvis/misc.c

   1 /* misc.c */
   2
   3 /* Author:
   4  *      Steve Kirkendall
   5  *      14407 SW Teal Blvd. #C
   6  *      Beaverton, OR 97005
   7  *      kirkenda@cs.pdx.edu
   8  */
   9
  10
  11 /* This file contains functions which didn't seem happy anywhere else */
  12
  13 #include "config.h"
  14 #include "vi.h"
  15
  16
  17 /* find a particular line & return a pointer to a copy of its text */
  18 char *fetchline(line)
  19         long    line;   /* line number of the line to fetch */
  20 {
  21         int             i;
  22         REG char        *scan;  /* used to search for the line in a BLK */
  23         long            l;      /* line number counter */
  24         static BLK      buf;    /* holds ONLY the selected line (as string) */
  25         REG char        *cpy;   /* used while copying the line */
  26         static long     nextline;       /* }  These four variables are used */
  27         static long     chglevel;       /*  } to implement a shortcut when  */
  28         static char     *nextscan;      /*  } consecutive lines are fetched */
  29         static long     nextlnum;       /* }                                */
  30
  31         /* can we do a shortcut? */
  32         if (changes == chglevel && line == nextline)
  33         {
  34                 scan = nextscan;
  35         }
  36         else
  37         {
  38                 /* scan lnum[] to determine which block its in */
  39                 for (i = 1; line > lnum[i]; i++)
  40                 {
  41                 }
  42                 nextlnum = lnum[i];
  43
  44                 /* fetch text of the block containing that line */
  45                 scan = blkget(i)->c;
  46
  47                 /* find the line in the block */
  48                 for (l = lnum[i - 1]; ++l < line; )
  49                 {
  50                         while (*scan++ != '\n')
  51                         {
  52                         }
  53                 }
  54         }
  55
  56         /* copy it into a block by itself, with no newline */
  57         for (cpy = buf.c; *scan != '\n'; )
  58         {
  59                 *cpy++ = *scan++;
  60         }
  61         *cpy = '\0';
  62
  63         /* maybe speed up the next call to fetchline() ? */
  64         if (line < nextlnum)
  65         {
  66                 nextline = line + 1;
  67                 chglevel = changes;
  68                 nextscan = scan + 1;
  69         }
  70         else
  71         {
  72                 nextline = 0;
  73         }
  74
  75         /* Calls to fetchline() interfere with calls to pfetch().  Make sure
  76          * that pfetch() resets itself on its next invocation.
  77          */
  78         pchgs = 0L;
  79
  80         /* Return a pointer to the line's text */
  81         return buf.c;
  82 }
  83
  84
  85 /* error message from the regexp code */
  86 void regerror(txt)
  87         char    *txt;   /* an error message */
  88 {
  89         msg("RE error: %s", txt);
  90 }
  91
  92 /* This function is equivelent to the pfetch() macro */
  93 void    pfetch(l)
  94         long    l;      /* line number of line to fetch */
  95 {
  96         if(l != pline || changes != pchgs)
  97         {
  98                 pline = (l);
  99                 ptext = fetchline(pline);
 100                 plen = strlen(ptext);
 101                 pchgs = changes;
 102         }
 103 }