add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/elvis/misc.c

@@ -0,0 +1,140 @@
+/* misc.c */
+
+/* Author:
+ *	Steve Kirkendall
+ *	16820 SW Tallac Way
+ *	Beaverton, OR 97006
+ *	kirkenda@jove.cs.pdx.edu, or ...uunet!tektronix!psueea!jove!kirkenda
+ */
+
+
+/* This file contains functions which didn't seem happy anywhere else */
+
+#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;
+	register 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) */
+	register 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;
+}
+
+/* find a particular line & delete it */
+deleteline(line)
+	long	line;	/* line number of the line to fetch */
+{
+	MARK	frommark, tomark;
+
+	frommark = MARK_AT_LINE(line);
+	tomark = frommark + BLKSIZE;
+	delete(frommark, tomark);
+}
+
+
+/* insert a given line at a particular line number */
+addline(l, txt)
+	long	l;	/* line number where the new line should go */
+	char	*txt;	/* text of line, terminated with '\0' (not '\n') */
+{
+	MARK	atmark;
+	BLK	newtext;
+
+	strcpy(newtext.c, txt);
+	strcat(newtext.c, "\n");
+	atmark = MARK_AT_LINE(l);
+	add(atmark, newtext.c);
+}
+
+
+/* replace one version of a line with another */
+changeline(l, txt)
+	long	l;	/* line# of line to change */
+	char	*txt;	/* new version of line, terminated with '\0' */
+{
+	deleteline(l);
+	addline(l, txt);
+}
+
+
+/* error message from the regexp code */
+void regerror(txt)
+	char	*txt;	/* an error message */
+{
+	msg("RE error: %s", txt);
+}
+
+#ifdef CRUNCH
+/* 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;
+	}
+}
+#endif