add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/elvis/move3.c

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+/* move3.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 movement functions that perform character searches */
+
+#include "vi.h"
+
+static MARK	(*prevfwdfn)();	/* function to search in same direction */
+static MARK	(*prevrevfn)();	/* function to search in opposite direction */
+static char	prev_key;	/* sought cvhar from previous [fFtT] */
+
+MARK	move_ch(m, cnt, cmd)
+	MARK	m;	/* current position */
+	long	cnt;
+	char	cmd;	/* command: either ',' or ';' */
+{
+	MARK	(*tmp)();
+
+	if (!prevfwdfn)
+	{
+		msg("No previous f, F, t, or T command");
+		return MARK_UNSET;
+	}
+
+	if (cmd == ',')
+	{
+		m =  (*prevrevfn)(m, cnt, prev_key);
+
+		/* Oops! we didn't want to change the prev*fn vars! */
+		tmp = prevfwdfn;
+		prevfwdfn = prevrevfn;
+		prevrevfn = tmp;
+
+		return m;
+	}
+	else
+	{
+		return (*prevfwdfn)(m, cnt, prev_key);
+	}
+}
+
+/* move forward within this line to next occurrence of key */
+MARK	movefch(m, cnt, key)
+	MARK	m;	/* where to search from */
+	long	cnt;
+	char	key;	/* what to search for */
+{
+	register char	*text;
+
+	DEFAULT(1);
+
+	prevfwdfn = movefch;
+	prevrevfn = moveFch;
+	prev_key = key;
+
+	pfetch(markline(m));
+	text = ptext + markidx(m);
+	while (cnt-- > 0)
+	{
+		do
+		{
+			m++;
+			text++;
+		} while (*text && *text != key);
+	}
+	if (!*text)
+	{
+		return MARK_UNSET;
+	}
+	return m;
+}
+
+/* move backward within this line to previous occurrence of key */
+MARK	moveFch(m, cnt, key)
+	MARK	m;	/* where to search from */
+	long	cnt;
+	char	key;	/* what to search for */
+{
+	register char	*text;
+
+	DEFAULT(1);
+
+	prevfwdfn = moveFch;
+	prevrevfn = movefch;
+	prev_key = key;
+
+	pfetch(markline(m));
+	text = ptext + markidx(m);
+	while (cnt-- > 0)
+	{
+		do
+		{
+			m--;
+			text--;
+		} while (text >= ptext && *text != key);
+	}
+	if (text < ptext)
+	{
+		return MARK_UNSET;
+	}
+	return m;
+}
+
+/* move forward within this line almost to next occurrence of key */
+MARK	movetch(m, cnt, key)
+	MARK	m;	/* where to search from */
+	long	cnt;
+	char	key;	/* what to search for */
+{
+	/* skip the adjacent char */
+	pfetch(markline(m));
+	if (plen <= markidx(m))
+	{
+		return MARK_UNSET;
+	}
+	m++;
+
+	m = movefch(m, cnt, key);
+	if (m == MARK_UNSET)
+	{
+		return MARK_UNSET;
+	}
+
+	prevfwdfn = movetch;
+	prevrevfn = moveTch;
+
+	return m - 1;
+}
+
+/* move backward within this line almost to previous occurrence of key */
+MARK	moveTch(m, cnt, key)
+	MARK	m;	/* where to search from */
+	long	cnt;
+	char	key;	/* what to search for */
+{
+	/* skip the adjacent char */
+	if (markidx(m) == 0)
+	{
+		return MARK_UNSET;
+	}
+	m--;
+
+	m = moveFch(m, cnt, key);
+	if (m == MARK_UNSET)
+	{
+		return MARK_UNSET;
+	}
+
+	prevfwdfn = moveTch;
+	prevrevfn = movetch;
+
+	return m + 1;
+}