Implement HISTCONTROL ignoredups & ignorespace features

ignoredups: don't save the current line if it is identical to the last
history line.
ignorespace: don't save the current line if it starts with a space

ok anton@ millert@

5 files changed, 70 insertions, 18 deletions

diff --git a/bin/ksh/history.c b/bin/ksh/history.c
index e0f98e489e7..bfc34932deb 100644
--- a/bin/ksh/history.c
+++ b/bin/ksh/history.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: history.c,v 1.68 2017/08/28 19:41:55 jca Exp $	*/
+/*	$OpenBSD: history.c,v 1.69 2017/08/30 17:08:45 jca Exp $	*/
 
 /*
  * command history
@@ -42,6 +42,8 @@ static FILE	*histfh;
 static char   **current;	/* current position in history[] */
 static char    *hname;		/* current name of history file */
 static int	hstarted;	/* set after hist_init() called */
+static int	ignoredups;	/* ditch duplicated history lines? */
+static int	ignorespace;	/* ditch lines starting with a space? */
 static Source	*hist_source;
 static uint32_t	line_co;
 
@@ -513,6 +515,28 @@ findhistrel(const char *str)
 	return start + rec + 1;
 }
 
+void
+sethistcontrol(const char *str)
+{
+	char *spec, *tok, *state;
+
+	ignorespace = 0;
+	ignoredups = 0;
+
+	if (str == NULL)
+		return;
+
+	spec = str_save(str, ATEMP);
+	for (tok = strtok_r(spec, ":", &state); tok != NULL;
+	     tok = strtok_r(NULL, ":", &state)) {
+		if (strcmp(tok, "ignoredups") == 0)
+			ignoredups = 1;
+		else if (strcmp(tok, "ignorespace") == 0)
+			ignorespace = 1;
+	}
+	afree(spec, ATEMP);
+}
+
 /*
  *	set history
  *	this means reallocating the dataspace
@@ -608,6 +632,18 @@ histsave(int lno, const char *cmd, int dowrite)
 {
 	char		*c, *cp;
 
+	if (ignorespace && cmd[0] == ' ')
+		return;
+
+	c = str_save(cmd, APERM);
+	if ((cp = strrchr(c, '\n')) != NULL)
+		*cp = '\0';
+
+	if (ignoredups && histptr >= history && strcmp(*histptr, c) == 0) {
+		afree(c, APERM);
+		return;
+	}
+
 	if (dowrite && histfh) {
 #ifndef SMALL
 		struct stat	sb;
@@ -624,10 +660,6 @@ histsave(int lno, const char *cmd, int dowrite)
 #endif
 	}
 
-	c = str_save(cmd, APERM);
-	if ((cp = strrchr(c, '\n')) != NULL)
-		*cp = '\0';
-
 	if (histptr < history + histsize - 1)
 		histptr++;
 	else { /* remove oldest command */
diff --git a/bin/ksh/ksh.1 b/bin/ksh/ksh.1
index 23b9654bc67..4471043038f 100644
--- a/bin/ksh/ksh.1
+++ b/bin/ksh/ksh.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ksh.1,v 1.194 2017/08/30 17:02:53 jca Exp $
+.\"	$OpenBSD: ksh.1,v 1.195 2017/08/30 17:08:45 jca Exp $
 .\"
 .\"	Public Domain
 .\"
@@ -1407,6 +1407,15 @@ It is also searched when a command can't be found using
 See
 .Sx Functions
 below for more information.
+.It Ev HISTCONTROL
+A colon separated list of history settings.
+If
+.Li ignoredups
+is present, lines identical to the previous history line will not be saved.
+If
+.Li ignorespace
+is present, lines starting with a space will not be saved.
+Unknown settings are ignored.
 .It Ev HISTFILE
 The name of the file used to store command history.
 When assigned to, history is loaded from the specified file.
diff --git a/bin/ksh/sh.h b/bin/ksh/sh.h
index b2b5164b887..6f0be4316d6 100644
--- a/bin/ksh/sh.h
+++ b/bin/ksh/sh.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sh.h,v 1.62 2017/08/30 17:02:53 jca Exp $	*/
+/*	$OpenBSD: sh.h,v 1.63 2017/08/30 17:08:45 jca Exp $	*/
 
 /*
  * Public Domain Bourne/Korn shell
@@ -457,6 +457,7 @@ void	hist_finish(void);
 void	histsave(int, const char *, int);
 #ifdef HISTORY
 int	c_fc(char **);
+void	sethistcontrol(const char *);
 void	sethistsize(int);
 void	sethistfile(const char *);
 char **	histpos(void);
diff --git a/bin/ksh/table.h b/bin/ksh/table.h
index 71cc3d17526..107790d3ce2 100644
--- a/bin/ksh/table.h
+++ b/bin/ksh/table.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: table.h,v 1.11 2015/10/10 07:35:16 nicm Exp $	*/
+/*	$OpenBSD: table.h,v 1.12 2017/08/30 17:08:45 jca Exp $	*/
 
 /* $From: table.h,v 1.3 1994/05/31 13:34:34 michael Exp $ */
 
@@ -160,15 +160,16 @@ extern const struct builtin shbuiltins [], kshbuiltins [];
 #define	V_MAILPATH		6
 #define	V_MAILCHECK		7
 #define	V_RANDOM		8
-#define V_HISTSIZE		9
-#define V_HISTFILE		10
-#define V_VISUAL		11
-#define V_EDITOR		12
-#define V_COLUMNS		13
-#define V_POSIXLY_CORRECT	14
-#define V_TMOUT			15
-#define V_TMPDIR		16
-#define V_LINENO		17
+#define	V_HISTCONTROL		9
+#define	V_HISTSIZE		10
+#define	V_HISTFILE		11
+#define	V_VISUAL		12
+#define	V_EDITOR		13
+#define	V_COLUMNS		14
+#define	V_POSIXLY_CORRECT	15
+#define	V_TMOUT			16
+#define	V_TMPDIR		17
+#define	V_LINENO		18
 
 /* values for set_prompt() */
 #define PS1	0		/* command */
diff --git a/bin/ksh/var.c b/bin/ksh/var.c
index fb19d36b59e..16805460d87 100644
--- a/bin/ksh/var.c
+++ b/bin/ksh/var.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: var.c,v 1.58 2017/08/30 10:18:48 jca Exp $	*/
+/*	$OpenBSD: var.c,v 1.59 2017/08/30 17:08:45 jca Exp $	*/
 
 #include <sys/stat.h>
 
@@ -98,6 +98,7 @@ initvar(void)
 		{ "POSIXLY_CORRECT",	V_POSIXLY_CORRECT },
 		{ "TMPDIR",		V_TMPDIR },
 #ifdef HISTORY
+		{ "HISTCONTROL",	V_HISTCONTROL },
 		{ "HISTFILE",		V_HISTFILE },
 		{ "HISTSIZE",		V_HISTSIZE },
 #endif /* HISTORY */
@@ -991,6 +992,9 @@ setspec(struct tbl *vp)
 		}
 		break;
 #ifdef HISTORY
+	case V_HISTCONTROL:
+		sethistcontrol(str_val(vp));
+		break;
 	case V_HISTSIZE:
 		vp->flag &= ~SPECIAL;
 		sethistsize((int) intval(vp));
@@ -1082,6 +1086,11 @@ unsetspec(struct tbl *vp)
 	case V_MAILPATH:
 		mpset(NULL);
 		break;
+#ifdef HISTORY
+	case V_HISTCONTROL:
+		sethistcontrol(NULL);
+		break;
+#endif
 	case V_LINENO:
 	case V_MAILCHECK:	/* at&t ksh leaves previous value in place */
 	case V_RANDOM: