implement “live” SIGWINCH handling in the Emacs editing mode

for winstonw from IRC #!/bin/mksh

Build.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.453 2010/07/04 17:33:53 tg Exp $'
+srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.454 2010/07/04 17:45:10 tg Exp $'
 #-
 # Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
 #	Thorsten Glaser <tg@mirbsd.org>
@@ -29,7 +29,7 @@ srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.453 2010/07/04 17:33:53 tg Exp $'
 #			MKSH_CONSERVATIVE_FDS MKSH_MIDNIGHTBSD01ASH_COMPAT
 #			MKSH_NOPWNAM MKSH_NO_LIMITS MKSH_SMALL MKSH_S_NOVI
 #			MKSH_UNEMPLOYED MKSH_DEFAULT_EXECSHELL MKSHRC_PATH
-#			MKSH_DEFAULT_TMPDIR
+#			MKSH_DEFAULT_TMPDIR MKSH_CLRTOEOL_STRING
 
 LC_ALL=C
 export LC_ALL

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.378 2010/05/22 12:49:13 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.379 2010/07/04 17:45:11 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -25,7 +25,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R39 2010/05/22
+	@(#)MIRBSD KSH R39 2010/07/04
 description:
 	Check version of shell.
 stdin:

edit.c

@@ -25,7 +25,20 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.192 2010/05/22 12:37:49 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.193 2010/07/04 17:45:12 tg Exp $");
+
+/*
+ * in later versions we might use libtermcap for this, but since external
+ * dependencies are problematic, this has not yet been decided on; another
+ * good string is "\033c" except on hardware terminals like the DEC VT420
+ * which do a full power cycle then...
+ */
+#ifndef MKSH_CLS_STRING
+#define MKSH_CLS_STRING		"\033[;H\033[J"
+#endif
+#ifndef MKSH_CLRTOEOL_STRING
+#define MKSH_CLRTOEOL_STRING	"\033[K"
+#endif
 
 /* tty driver characters we are interested in */
 typedef struct {
@@ -45,6 +58,7 @@ static X_chars edchars;
 #define XCF_FULLPATH	BIT(2)	/* command completion: store full path */
 #define XCF_COMMAND_FILE (XCF_COMMAND|XCF_FILE)
 
+static char editmode;
 static int modified;			/* buffer has been "modified" */
 static char holdbuf[LINE];		/* place to hold last edit buffer */
 
@@ -67,7 +81,11 @@ static int x_vi(char *, size_t);
 #endif
 
 #define x_flush()	shf_flush(shl_out)
+#ifdef MKSH_SMALL
+#define x_putc(c)	x_putcf(c)
+#else
 #define x_putc(c)	shf_putc((c), shl_out)
+#endif
 
 static int path_order_cmp(const void *aa, const void *bb);
 static char *add_glob(const char *, int)
@@ -84,6 +102,7 @@ static int x_command_glob(int, const char *, int, char ***)
 static int x_locate_word(const char *, int, int, int *, bool *);
 
 static int x_e_getmbc(char *);
+static int x_e_rebuildline(const char *);
 
 /* +++ generic editing functions +++ */
 
@@ -96,7 +115,6 @@ x_init(void)
 	    edchars.eof = -2;
 	/* default value for deficient systems */
 	edchars.werase = 027;	/* ^W */
-	change_winsz();
 	x_init_emacs();
 }
 
@@ -118,8 +136,8 @@ x_read(char *buf, size_t len)
 #endif
 	else
 		i = -1;		/* internal error */
+	editmode = 0;
 	x_mode(false);
-	change_winsz();
 	return (i);
 }
 
@@ -1091,6 +1109,7 @@ x_emacs(char *buf, size_t len)
 			x_load_hist(histptr - off);
 		x_nextcmd = -1;
 	}
+	editmode = 1;
 	while (1) {
 		x_flush();
 		if ((c = x_e_getc()) < 0)
@@ -1922,23 +1941,18 @@ x_draw_line(int c MKSH_A_UNUSED)
 	return (KSTD);
 }
 
+static int
+x_e_rebuildline(const char *clrstr)
+{
+	shf_fprintf(shl_out, clrstr);
+	x_adjust();
+	return (KSTD);
+}
+
 static int
 x_cls(int c MKSH_A_UNUSED)
 {
-/*
+	return (x_e_rebuildline(MKSH_CLS_STRING));
- * in later versions we might use libtermcap for this, but since external
- * dependencies are problematic, this has not yet been decided on; another
- * good string is "\033c" except on hardware terminals like the DEC VT420
- * which do a full power cycle then...
- */
-#ifndef MKSH_CLS_STRING
-#define MKSH_CLS_STRING	"\033[;H\033[J"
-#endif
-	shf_fprintf(shl_out, MKSH_CLS_STRING);
-	x_putc('\r');
-	x_init_prompt();
-	x_redraw(0);
-	return (KSTD);
 }
 
 /* Redraw (part of) the line. If limit is < 0, the everything is redrawn
@@ -3096,6 +3110,15 @@ x_mode(bool onoff)
 	static bool x_cur_mode;
 	bool prev;
 
+	if (onoff && got_winch) {
+		change_winsz();
+		if (x_cols != xx_cols && editmode == 1) {
+			/* redraw line in Emacs mode */
+			xx_cols = x_cols;
+			x_e_rebuildline(MKSH_CLRTOEOL_STRING);
+		}
+	}
+
 	if (x_cur_mode == onoff)
 		return (x_cur_mode);
 	prev = x_cur_mode;
@@ -3381,6 +3404,7 @@ x_vi(char *buf, size_t len)
 	lastref = 1;
 	holdlen = 0;
 
+	editmode = 2;
 	x_flush();
 	while (1) {
 		if (macro.p) {

histrap.c

@@ -26,7 +26,7 @@
 #include <sys/file.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.95 2010/07/04 13:36:42 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.96 2010/07/04 17:45:14 tg Exp $");
 
 /*-
  * MirOS: This is the default mapping type, and need not be specified.
@@ -1433,9 +1433,10 @@ setsig(Trap *p, sig_t f, int flags)
 	setexecsig(p, flags & SS_RESTORE_MASK);
 
 	/*
-	 * This is here 'cause there should be a way of clearing shtraps,
+	 * This is here 'cause there should be a way of clearing
-	 * but don't know if this is a sane way of doing it. At the moment,
+	 * shtraps, but don't know if this is a sane way of doing
-	 * all users of shtrap are lifetime users (SIGCHLD, SIGALRM).
+	 * it. At the moment, all users of shtrap are lifetime
+	 * users (SIGALRM, SIGCHLD, SIGWINCH).
 	 */
 	if (!(flags & SS_USER))
 		p->shtrap = (sig_t)NULL;

lex.c

@@ -22,7 +22,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.113 2010/04/08 13:21:06 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.114 2010/07/04 17:45:14 tg Exp $");
 
 /*
  * states while lexing word
@@ -1406,6 +1406,8 @@ getsc_line(Source *s)
 		xp += nread;
 	} else {
 		if (interactive) {
+			if (got_winch)
+				change_winsz();
 			pprompt(prompt, 0);
 		} else
 			s->line++;

main.c

@@ -33,7 +33,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.166 2010/07/04 17:33:55 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.167 2010/07/04 17:45:15 tg Exp $");
 
 extern char **environ;
 
@@ -54,6 +54,9 @@ static void reclaim(void);
 static void remove_temps(struct temp *);
 void chvt_reinit(void);
 Source *mksh_init(int, const char *[]);
+#ifdef SIGWINCH
+static void x_sigwinch(int);
+#endif
 
 static const char initifs[] = "IFS= \t\n";
 
@@ -399,6 +402,12 @@ mksh_init(int argc, const char *argv[])
 		x_init();
 	}
 
+#ifdef SIGWINCH
+	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
+	setsig(&sigtraps[SIGWINCH], x_sigwinch,
+	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
+#endif
+
 	l = e->loc;
 	l->argv = &argv[argi - 1];
 	l->argc = argc - argi;
@@ -1459,3 +1468,13 @@ ktsort(struct table *tp)
 	p[i] = NULL;
 	return (p);
 }
+
+#ifdef SIGWINCH
+static void
+x_sigwinch(int sig MKSH_A_UNUSED)
+{
+	/* this runs inside interrupt context, with errno saved */
+
+	got_winch = 1;
+}
+#endif

sh.h

@@ -150,9 +150,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.394 2010/07/04 17:33:57 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.395 2010/07/04 17:45:16 tg Exp $");
 #endif
-#define MKSH_VERSION "R39 2010/05/22"
+#define MKSH_VERSION "R39 2010/07/04"
 
 #ifndef MKSH_INCLUDES_ONLY
 
@@ -665,7 +665,7 @@ typedef struct trap {
 #define SS_RESTORE_IGN	3	/* restore to SIG_IGN */
 #define SS_FORCE	BIT(3)	/* set signal even if original signal ignored */
 #define SS_USER		BIT(4)	/* user is doing the set (ie, trap command) */
-#define SS_SHTRAP	BIT(5)	/* trap for internal use (SIGCHLD, SIGALRM) */
+#define SS_SHTRAP	BIT(5)	/* trap for internal use (ALRM, CHLD, WINCH) */
 
 #define SIGEXIT_	0	/* for trap EXIT */
 #define SIGERR_		NSIG	/* for trap ERR */
@@ -675,6 +675,13 @@ EXTERN volatile sig_atomic_t intrsig;	/* pending trap interrupts command */
 EXTERN volatile sig_atomic_t fatal_trap;/* received a fatal signal */
 extern	Trap	sigtraps[NSIG+1];
 
+/* got_winch = 1 when needing to re-adjust the window size */
+#ifdef SIGWINCH
+EXTERN volatile sig_atomic_t got_winch I__(1);
+#else
+#define got_winch	true
+#endif
+
 /*
  * TMOUT support
  */

var.c

@@ -22,7 +22,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/var.c,v 1.105 2010/07/04 17:33:58 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/var.c,v 1.106 2010/07/04 17:45:17 tg Exp $");
 
 /*
  * Variables
@@ -1440,6 +1440,10 @@ change_winsz(void)
 		x_cols = 80;
 	if (x_lins < MIN_LINS)
 		x_lins = 24;
+
+#ifdef SIGWINCH
+	got_winch = 0;
+#endif
 }
 
 uint32_t