add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/elvis/move2.c

@@ -0,0 +1,194 @@
+/* move2.c */
+
+/* Author:
+ *	Steve Kirkendall
+ *	16820 SW Tallac Way
+ *	Beaverton, OR 97006
+ *	kirkenda@jove.cs.pdx.edu, or ...uunet!tektronix!psueea!jove!kirkenda
+ */
+
+
+/* This function contains the mvoement functions that perform RE searching */
+
+#include "vi.h"
+#include "regexp.h"
+
+static regexp	*re;	/* compiled version of the pattern to search for */
+static		prevsf;	/* boolean: previous search direction was forward? */
+
+MARK	movensrch(m)
+	MARK	m;	/* where to start searching */
+{
+	if (prevsf)
+	{
+		m = movefsrch(m, "");
+		prevsf = TRUE;
+	}
+	else
+	{
+		m = movebsrch(m, "");
+		prevsf = FALSE;
+	}
+	return m;
+}
+
+MARK	moveNsrch(m)
+	MARK	m;	/* where to start searching */
+{
+	if (prevsf)
+	{
+		m = movebsrch(m, "");
+		prevsf = TRUE;
+	}
+	else
+	{
+		m = movefsrch(m, "");
+		prevsf = FALSE;
+	}
+	return m;
+}
+
+MARK	movefsrch(m, ptrn)
+	MARK	m;	/* where to start searching */
+	char	*ptrn;	/* pattern to search for */
+{
+	long	l;	/* line# of line to be searched */
+	char	*line;	/* text of line to be searched */
+	int	wrapped;/* boolean: has our search wrapped yet? */
+	int	pos;	/* where we are in the line */
+
+	/* remember: "previous search was forward" */
+	prevsf = TRUE;
+
+	if (ptrn && *ptrn)
+	{
+		/* free the previous pattern */
+		if (re) free(re);
+
+		/* compile the pattern */
+		re = regcomp(ptrn);
+		if (!re)
+		{
+			return MARK_UNSET;
+		}
+	}
+	else if (!re)
+	{
+		msg("No previous expression");
+		return MARK_UNSET;
+	}
+
+	/* search forward for the pattern */
+	pos = markidx(m) + 1;
+	wrapped = FALSE;
+	for (l = markline(m); l != markline(m) + 1 || !wrapped; l++)
+	{
+		/* wrap search */
+		if (l > nlines)
+		{
+			if (*o_wrapscan)
+			{
+				l = 0;
+				wrapped = TRUE;
+				continue;
+			}
+			else
+			{
+				break;
+			}
+		}
+
+		/* get this line */
+		line = fetchline(l);
+
+		/* check this line */
+		if (regexec(re, &line[pos], (pos == 0)))
+		{
+			/* match! */
+			return MARK_AT_LINE(l) + (int)(re->startp[0] - line);
+		}
+		pos = 0;
+	}
+
+	/* not found */
+	msg(*o_wrapscan ? "Not found" : "Hit bottom without finding RE");
+	return MARK_UNSET;
+}
+
+MARK	movebsrch(m, ptrn)
+	MARK	m;	/* where to start searching */
+	char	*ptrn;	/* pattern to search for */
+{
+	long	l;	/* line# of line to be searched */
+	char	*line;	/* text of line to be searched */
+	int	wrapped;/* boolean: has our search wrapped yet? */
+	int	pos;	/* last acceptable idx for a match on this line */
+	int	last;	/* remembered idx of the last acceptable match on this line */
+	int	try;	/* an idx at which we strat searching for another match */
+
+	/* remember: "previous search was not forward" */
+	prevsf = FALSE;
+
+	if (ptrn && *ptrn)
+	{
+		/* free the previous pattern, if any */
+		if (re) free(re);
+
+		/* compile the pattern */
+		re = regcomp(ptrn);
+		if (!re)
+		{
+			return MARK_UNSET;
+		}
+	}
+	else if (!re)
+	{
+		msg("No previous expression");
+		return MARK_UNSET;
+	}
+
+	/* search backward for the pattern */
+	pos = markidx(m);
+	wrapped = FALSE;
+	for (l = markline(m); l != markline(m) - 1 || !wrapped; l--)
+	{
+		/* wrap search */
+		if (l < 1)
+		{
+			if (*o_wrapscan)
+			{
+				l = nlines + 1;
+				wrapped = TRUE;
+				continue;
+			}
+			else
+			{
+				break;
+			}
+		}
+
+		/* get this line */
+		line = fetchline(l);
+
+		/* check this line */
+		if (regexec(re, line, 1) && (int)(re->startp[0] - line) < pos)
+		{
+			/* match!  now find the last acceptable one in this line */
+			do
+			{
+				last = (int)(re->startp[0] - line);
+				try = (int)(re->endp[0] - line);
+			} while (try > 0
+				 && regexec(re, &line[try], FALSE)
+				 && (int)(re->startp[0] - line) < pos);
+
+			return MARK_AT_LINE(l) + last;
+		}
+		pos = BLKSIZE;
+	}
+
+	/* not found */
+	msg(*o_wrapscan ? "Not found" : "Hit top without finding RE");
+	return MARK_UNSET;
+}
+