• add -u option (POSIX: unbuffered ⇒ nop) to the built-in cat

• PIPESTATUS now supported (like bash 2) whose last member
  may actually differ from $? since the latter may not be the
  result of a pipeline partial command
• add regression tests, documentation, etc.

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.408 2011/02/13 21:13:05 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.409 2011/02/18 22:26:06 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 2011/02/13
+	@(#)MIRBSD KSH R39 2011/02/18
 description:
 	Check version of shell.
 stdin:
@@ -69,8 +69,9 @@ name: selftest-direct-builtin-call
 description:
 	Check that direct builtin calls work
 stdin:
+	ln -s "$__progname" cat
 	ln -s "$__progname" echo
-	./echo -c 'echo  foo'
+	./echo -c 'echo  foo' | ./cat -u
 expected-stdout:
 	-c echo  foo
 ---
@@ -5244,6 +5245,28 @@ expected-stdout:
 	200 hi
 	300 hi
 ---
+name: pipeline-3
+description:
+	Check that PIPESTATUS does what it's supposed to
+stdin:
+	echo 1 $PIPESTATUS .
+	echo 2 ${PIPESTATUS[0]} .
+	echo 3 ${PIPESTATUS[1]} .
+	(echo x; exit 12) | (cat; exit 23) | (cat; exit 42)
+	echo 5 $? , $PIPESTATUS , ${PIPESTATUS[0]} , ${PIPESTATUS[1]} , ${PIPESTATUS[2]} , ${PIPESTATUS[3]} .
+	echo 6 ${PIPESTATUS[0]} .
+	set | fgrep PIPESTATUS
+	echo 8 $(set | fgrep PIPESTATUS) .
+expected-stdout:
+	1 0 .
+	2 0 .
+	3 .
+	x
+	5 42 , 12 , 12 , 23 , 42 , .
+	6 0 .
+	PIPESTATUS[0]=0
+	8 PIPESTATUS[0]=0 PIPESTATUS[1]=0 .
+---
 name: persist-history-1
 description:
 	Check if persistent history saving works

exec.c

@@ -22,7 +22,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.86 2011/02/11 01:18:16 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.87 2011/02/18 22:26:08 tg Exp $");
 
 #ifndef MKSH_DEFAULT_EXECSHELL
 #define MKSH_DEFAULT_EXECSHELL	"/bin/sh"
@@ -153,6 +153,9 @@ execute(struct op * volatile t,
 		memset(e->savefd, 0, NUFILE * sizeof(short));
 	}
 
+	/* mark for replacement later (unless TPIPE) */
+	vp_pipest->flag |= INT_L;
+
 	/* do redirection, to be restored in quitenv() */
 	if (t->ioact != NULL)
 		for (iowp = t->ioact; *iowp != NULL; iowp++) {
@@ -207,7 +210,7 @@ execute(struct op * volatile t,
 		/* no need to re-restore this */
 		e->savefd[1] = 0;
 		/* Let exchild() close 0 in parent, after fork, before wait */
-		i = exchild(t, flags | XPCLOSE, xerrok, 0);
+		i = exchild(t, flags | XPCLOSE | XPIPEST, xerrok, 0);
 		if (!(flags&XBGND) && !(flags&XXCOM))
 			rv = i;
 		break;
@@ -449,6 +452,12 @@ execute(struct op * volatile t,
 	}
  Break:
 	exstat = rv;
+	if (vp_pipest->flag & INT_L) {
+		unset(vp_pipest, 1);
+		vp_pipest->flag = DEFINED | ISSET | INTEGER | RDONLY |
+		    ARRAY | INT_U;
+		vp_pipest->val.i = rv;
+	}
 
 	/* restores IO */
 	quitenv(NULL);
@@ -570,6 +579,8 @@ comexec(struct op *t, struct tbl * volatile tp, const char **ap,
 			 * in theory, we could allow -u, but that would
 			 * mean to use ksh_getopt here and possibly ad-
 			 * ded complexity and more code and isn't worth
+			 * additional hassle (and the builtin must call
+			 * ksh_getopt already but can't come back here)
 			 */
 			if (ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
 			    /* argument, begins with -, is not - or -- */

funcs.c

@@ -38,7 +38,7 @@
 #endif
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.171 2011/02/13 21:13:06 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.172 2011/02/18 22:26:08 tg Exp $");
 
 #if HAVE_KILLPG
 /*
@@ -3599,7 +3599,7 @@ c_realpath(const char **wp)
 int
 c_cat(const char **wp)
 {
-	int fd = STDIN_FILENO, rv = 0;
+	int fd = STDIN_FILENO, rv;
 	ssize_t n, w;
 	const char *fn = "<stdin>";
 	char *buf, *cp;
@@ -3611,11 +3611,19 @@ c_cat(const char **wp)
 		return (1);
 	}
 
-	/* skip argv[0] */
+	/* parse options: POSIX demands we support "-u" as no-op */
-	++wp;
+	while ((rv = ksh_getopt(wp, &builtin_opt, "u")) != -1) {
-	if (wp[0] && !strcmp(wp[0], "--"))
+		switch (rv) {
-		/* skip "--" (options separator) */
+		case 'u':
-		++wp;
+			/* we already operate unbuffered */
+			break;
+		default:
+			bi_errorf(T_synerr);
+			return (1);
+		}
+	}
+	wp += builtin_opt.optind;
+	rv = 0;
 
 	do {
 		if (*wp) {

jobs.c

@@ -22,7 +22,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/jobs.c,v 1.74 2011/01/30 01:35:34 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/jobs.c,v 1.75 2011/02/18 22:26:09 tg Exp $");
 
 #if HAVE_KILLPG
 #define mksh_killpg		killpg
@@ -97,6 +97,7 @@ struct job {
 #define JW_INTERRUPT	0x01	/* ^C will stop the wait */
 #define JW_ASYNCNOTIFY	0x02	/* asynchronous notification during wait ok */
 #define JW_STOPPEDWAIT	0x04	/* wait even if job stopped */
+#define JW_PIPEST	0x08	/* want PIPESTATUS */
 
 /* Error codes for j_lookup() */
 #define JL_OK		0
@@ -207,6 +208,19 @@ j_init(void)
 		tty_init(true, true);
 }
 
+static int
+proc_errorlevel(Proc *p)
+{
+	switch (p->state) {
+	case PEXITED:
+		return (WEXITSTATUS(p->status));
+	case PSIGNALLED:
+		return (128 + WTERMSIG(p->status));
+	default:
+		return (0);
+	}
+}
+
 /* job cleanup before shell exit */
 void
 j_exit(void)
@@ -349,7 +363,7 @@ exchild(struct op *t, int flags,
 	/* for pipelines */
 	static Proc *last_proc;
 
-	int rv = 0, forksleep;
+	int rv = 0, forksleep, jwflags = JW_NONE;
 #ifndef MKSH_NOPROSPECTOFWORK
 	sigset_t omask;
 #endif
@@ -357,6 +371,11 @@ exchild(struct op *t, int flags,
 	Job *j;
 	pid_t cldpid;
 
+	if (flags & XPIPEST) {
+		flags &= ~XPIPEST;
+		jwflags |= JW_PIPEST;
+	}
+
 	if (flags & XEXEC)
 		/*
 		 * Clear XFORK|XPCLOSE|XCCLOSE|XCOPROC|XPIPEO|XPIPEI|XXCOM|XBGND
@@ -543,7 +562,7 @@ exchild(struct op *t, int flags,
 				shf_flush(shl_out);
 			}
 		} else
-			rv = j_waitj(j, JW_NONE, "jw:last proc");
+			rv = j_waitj(j, jwflags, "jw:last proc");
 	}
 
 #ifndef MKSH_NOPROSPECTOFWORK
@@ -1158,6 +1177,38 @@ j_waitj(Job *j,
 	j_systime = j->systime;
 	rv = j->status;
 
+	if ((flags & JW_PIPEST) && (j->proc_list != NULL)) {
+		size_t num = 0;
+		Proc *p = j->proc_list;
+		struct tbl *vp;
+
+		unset(vp_pipest, 1);
+		vp = vp_pipest;
+		vp->flag = DEFINED | ISSET | INTEGER | RDONLY | ARRAY | INT_U;
+		goto got_array;
+
+		while (p != NULL) {
+			{
+				struct tbl *vq;
+
+				/* strlen(vp_pipest->name) == 10 */
+				vq = alloc(offsetof(struct tbl, name[0]) + 11,
+				    vp_pipest->areap);
+				memset(vq, 0, offsetof(struct tbl, name[0]));
+				memcpy(vq->name, vp_pipest->name, 11);
+				vp->u.array = vq;
+				vp = vq;
+			}
+			vp->areap = vp_pipest->areap;
+			vp->ua.index = ++num;
+			vp->flag = DEFINED | ISSET | INTEGER | RDONLY |
+			    ARRAY | INT_U | AINDEX;
+ got_array:
+			vp->val.i = proc_errorlevel(p);
+			p = p->next;
+		}
+	}
+
 	if (!(flags & JW_ASYNCNOTIFY)
 #ifndef MKSH_UNEMPLOYED
 	    && (!Flag(FMONITOR) || j->state != PSTOPPED)
@@ -1295,18 +1346,7 @@ check_job(Job *j)
 			jstate = p->state;
 	}
 	j->state = jstate;
-
+	j->status = proc_errorlevel(j->last_proc);
-	switch (j->last_proc->state) {
-	case PEXITED:
-		j->status = WEXITSTATUS(j->last_proc->status);
-		break;
-	case PSIGNALLED:
-		j->status = 128 + WTERMSIG(j->last_proc->status);
-		break;
-	default:
-		j->status = 0;
-		break;
-	}
 
 	/*
 	 * Note when co-process dies: can't be done in j_wait() nor

main.c

@@ -33,7 +33,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.176 2011/02/11 01:18:18 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.177 2011/02/18 22:26:10 tg Exp $");
 
 extern char **environ;
 
@@ -364,6 +364,7 @@ main(int argc, const char *argv[])
 	vp->flag |= INT_U;
 	setint((vp = global("RANDOM")), rndsetup());
 	vp->flag |= INT_U;
+	setint((vp_pipest = global("PIPESTATUS")), 0);
 
 	/* Set this before parsing arguments */
 	Flag(FPRIVILEGED) = kshuid != ksheuid || kshgid != kshegid;

mksh.1

@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.250 2011/02/11 01:18:19 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.251 2011/02/18 22:26:11 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.138 2010/09/20 07:41:17 jmc Exp $
 .\"-
 .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
@@ -72,7 +72,7 @@
 .\" with -mandoc, it might implement .Mx itself, but we want to
 .\" use our own definition. And .Dd must come *first*, always.
 .\"
-.Dd $Mdocdate: February 11 2011 $
+.Dd $Mdocdate: February 18 2011 $
 .\"
 .\" Check which macro package we use
 .\"
@@ -1672,7 +1672,7 @@ arguments or splitting arguments with spaces.
 .El
 .Pp
 The following parameters are set and/or used by the shell:
-.Bl -tag -width "EXECSHELL"
+.Bl -tag -width "PIPESTATUS"
 .It Ev _ No (underscore)
 When an external command is executed by the shell, this parameter is set in the
 environment of the new process to the path of the executed command.
@@ -1825,6 +1825,9 @@ colon, or two adjacent colons, is treated as a
 (the current directory).
 .It Ev PGRP
 The process ID of the shell's process group leader.
+.It Ev PIPESTATUS
+An array containing the errorlevel (exit status) codes,
+one by one, of the last pipeline run in the foreground.
 .It Ev PPID
 The process ID of the shell's parent.
 .It Ev PS1
@@ -2995,19 +2998,23 @@ Execute the built-in command
 .Pp
 .It Xo
 .Ic cat
-.Op Fl \-
+.Op Fl u
 .Op Ar
 .Xc
 Read files sequentially, in command line order, and write them to
 standard output.
-If
+If a
 .Ar file
 is a single dash
 .Pq Sq -
 or absent, read from standard input.
 If any options are given, an external
 .Xr cat 1
-utility is invoked instead.
+utility is invoked instead if called from the shell.
+For direct builtin calls, the
+.Tn POSIX
+.Fl u
+option is supported as a no-op.
 .Pp
 .It Xo
 .Ic cd
@@ -4695,7 +4702,7 @@ Impose a limit of
 processes that can be run by the user at any one time.
 .It Fl q Ar n
 Limit the size of
-.Px
+.Tn POSIX
 message queues to
 .Ar n
 bytes.

sh.h

@@ -154,9 +154,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.431 2011/02/13 21:13:08 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.432 2011/02/18 22:26:13 tg Exp $");
 #endif
-#define MKSH_VERSION "R39 2011/02/13"
+#define MKSH_VERSION "R39 2011/02/18"
 
 #ifndef MKSH_INCLUDES_ONLY
 
@@ -577,6 +577,7 @@ extern struct env {
 EXTERN pid_t procpid;		/* PID of executing process */
 EXTERN int exstat;		/* exit status */
 EXTERN int subst_exstat;	/* exit status of last $(..)/`..` */
+EXTERN struct tbl *vp_pipest;	/* global PIPESTATUS array */
 EXTERN short trap_exstat;	/* exit status before running a trap */
 EXTERN uint8_t trap_nested;	/* running nested traps */
 EXTERN uint8_t shell_flags[FNFLAGS];
@@ -948,7 +949,7 @@ struct tbl {			/* table item */
 #define LCASEV		BIT(17)	/* convert to lower case */
 #define UCASEV_AL	BIT(18) /* convert to upper case / autoload function */
 #define INT_U		BIT(19)	/* unsigned integer */
-#define INT_L		BIT(20)	/* long integer (no-op) */
+#define INT_L		BIT(20)	/* long integer (no-op but used as magic) */
 #define IMPORT		BIT(21)	/* flag to typeset(): no arrays, must have = */
 #define LOCAL_COPY	BIT(22)	/* with LOCAL - copy attrs from existing var */
 #define EXPRINEVAL	BIT(23)	/* contents currently being evaluated */
@@ -1162,6 +1163,7 @@ struct ioword {
 #define XERROK	BIT(8)		/* non-zero exit ok (for set -e) */
 #define XCOPROC BIT(9)		/* starting a co-process */
 #define XTIME	BIT(10)		/* timing TCOM command */
+#define XPIPEST	BIT(11)		/* want PIPESTATUS */
 
 /*
  * flags to control expansion of words (assumed by t->evalflags to fit