From f13dc04bbbf1b663e6e431df9848a04d5ba2eb4b Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Wed, 27 Nov 2024 10:36:26 -0800
Subject: [PATCH 1/9] Externalize printstatus() as %print-status.

Also add $&sigmessage primitive.
---
 eval.c     |  2 +-
 initial.es | 23 +++++++++++++++++++++--
 prim-io.c  | 13 +++++++------
 prim-sys.c | 29 +++++++++++++++++++++++++----
 status.c   | 23 ++++++++++-------------
 5 files changed, 64 insertions(+), 26 deletions(-)

diff --git a/eval.c b/eval.c
index 8e36896b..43c6d2d3 100644
--- a/eval.c
+++ b/eval.c
@@ -41,7 +41,7 @@ extern List *forkexec(char *file, List *list, Boolean inchild) {
 		sigint_newline = TRUE;
 	} else
 		SIGCHK();
-	printstatus(0, status);
+	printstatus(pid, status);
 	return mklist(mkterm(mkstatus(status), NULL), NULL);
 }
 
diff --git a/initial.es b/initial.es
index 70a5982d..638028b3 100644
--- a/initial.es
+++ b/initial.es
@@ -76,7 +76,6 @@ fn-newpgrp	= $&newpgrp
 fn-result	= $&result
 fn-throw	= $&throw
 fn-umask	= $&umask
-fn-wait		= $&wait
 
 fn-%read	= $&read
 
@@ -579,6 +578,26 @@ fn %pathsearch name { access -n $name -1e -xf $path }
 
 if {~ <=$&primitives execfailure} {fn-%exec-failure = $&execfailure}
 
+#	The %print-status hook is used to print any potentially interesting
+#	status from an exec()ed binary.
+
+fn %print-status pid did status {
+	if {~ $did signaled} {
+		let (msg = <={if {$print-status-pid} {result $pid^': '} {result ''}}) {
+			msg = $msg^<={$&sigmessage $status}
+			if {~ $status *+core} {
+				msg = $msg^'--core dumped'
+			}
+			echo >[1=2] $msg
+		}
+	}
+}
+
+print-status-pid = false
+
+fn wait {
+	local (print-status-pid = true) $&wait $*
+}
 
 #
 # Read-eval-print loops
@@ -756,7 +775,7 @@ max-eval-depth	= 640
 #	is does.  fn-%dispatch is really only important to the current
 #	interpreter loop.
 
-noexport = noexport pid signals apid bqstatus fn-%dispatch path home matchexpr
+noexport = noexport pid signals apid bqstatus fn-%dispatch path home matchexpr print-status-pid
 
 
 #
diff --git a/prim-io.c b/prim-io.c
index 9cd35b4a..a8d293a3 100644
--- a/prim-io.c
+++ b/prim-io.c
@@ -234,9 +234,10 @@ PRIM(pipe) {
 
 	Ref(List *, result, NULL);
 	do {
+		int pid = pids[--n];
 		Term *t;
-		int status = ewaitfor(pids[--n]);
-		printstatus(0, status);
+		int status = ewaitfor(pid);
+		printstatus(pid, status);
 		t = mkstr(mkstatus(status));
 		result = mklist(t, result);
 	} while (0 < n);
@@ -280,7 +281,7 @@ PRIM(readfrom) {
 
 	close(p[0]);
 	status = ewaitfor(pid);
-	printstatus(0, status);
+	printstatus(pid, status);
 	varpop(&push);
 	RefEnd3(cmd, input, var);
 	RefReturn(lp);
@@ -320,7 +321,7 @@ PRIM(writeto) {
 
 	close(p[1]);
 	status = ewaitfor(pid);
-	printstatus(0, status);
+	printstatus(pid, status);
 	varpop(&push);
 	RefEnd3(cmd, output, var);
 	RefReturn(lp);
@@ -365,11 +366,11 @@ PRIM(backquote) {
 	}
 
 	close(p[1]);
-	gcdisable();
 	lp = bqinput(sep, p[0]);
 	close(p[0]);
 	status = ewaitfor(pid);
-	printstatus(0, status);
+	printstatus(pid, status);
+	gcdisable();
 	lp = mklist(mkstr(mkstatus(status)), lp);
 	gcenable();
 	list = lp;
diff --git a/prim-sys.c b/prim-sys.c
index 0506df8a..a52b59b5 100644
--- a/prim-sys.c
+++ b/prim-sys.c
@@ -56,7 +56,7 @@ PRIM(fork) {
 		esexit(exitstatus(eval(list, NULL, evalflags | eval_inchild)));
 	status = ewaitfor(pid);
 	SIGCHK();
-	printstatus(0, status);
+	printstatus(pid, status);
 	return mklist(mkstr(mkstatus(status)), NULL);
 }
 
@@ -128,6 +128,26 @@ PRIM(setsignals) {
 	return mksiglist();
 }
 
+PRIM(sigmessage) {
+	int sig;
+	char *s, *p;
+	if (list == NULL || list->next != NULL)
+		fail("$&sigmessage", "usage: $&sigmessage signal");
+	s = getstr(list->term);
+	if ((p = strchr(s, '+')) != NULL) {
+		if (streq(p, "+core"))
+			*p = '\0';
+		else
+			p = NULL;
+	}
+	sig = signumber(s);
+	if (p != NULL)
+		*p = '+';
+	if (sig < 0)
+		fail("$&sigmessage", "unknown signal: %s", s);
+	return mklist(mkstr(sigmessage(sig)), NULL);
+}
+
 /*
  * limit builtin -- this is too much code for what it gives you
  */
@@ -306,7 +326,7 @@ PRIM(time) {
 	status = ewait(pid, FALSE, &r);
 	t1 = time(NULL);
 	SIGCHK();
-	printstatus(0, status);
+	printstatus(pid, status);
 
 	eprint(
 		"%6ldr %5ld.%ldu %5ld.%lds\t%L\n",
@@ -342,7 +362,7 @@ PRIM(time) {
 		status = ewaitfor(pid);
 		t1 = times(&tms);
 		SIGCHK();
-		printstatus(0, status);
+		printstatus(pid, status);
 
 		tms.tms_cutime += ticks / 20;
 		tms.tms_cstime += ticks / 20;
@@ -358,7 +378,7 @@ PRIM(time) {
 	}
 	status = ewaitfor(pid);
 	SIGCHK();
-	printstatus(0, status);
+	printstatus(pid, status);
 
 	RefEnd(lp);
 	return mklist(mkstr(mkstatus(status)), NULL);
@@ -439,6 +459,7 @@ extern Dict *initprims_sys(Dict *primdict) {
 	X(fork);
 	X(run);
 	X(setsignals);
+	X(sigmessage);
 #if BSD_LIMITS
 	X(limit);
 #endif
diff --git a/status.c b/status.c
index 13dd47ed..c72c552b 100644
--- a/status.c
+++ b/status.c
@@ -65,18 +65,15 @@ extern char *mkstatus(int status) {
 
 /* printstatus -- print the status if we should */
 extern void printstatus(int pid, int status) {
-	if (WIFSIGNALED(status)) {
-		const char *msg = sigmessage(WTERMSIG(status)), *tail = "";
-		if (WCOREDUMP(status)) {
-			tail = "--core dumped";
-			if (*msg == '\0')
-				tail += (sizeof "--") - 1;
-		}
-		if (*msg != '\0' || *tail != '\0') {
-			if (pid == 0)
-				eprint("%s%s\n", msg, tail);
-			else
-				eprint("%d: %s%s\n", pid, msg, tail);
-		}
+	Ref(List *, fn, varlookup("fn-%print-status", NULL));
+	Ref(List *, list, NULL);
+	if (fn != NULL) {
+		gcdisable();
+		list = mklist(mkstr(mkstatus(status)), NULL);
+		list = mklist(mkstr((WIFSIGNALED(status) ? "signaled" : "exited")), list);
+		list = mklist(mkstr(str("%d", pid)), list);
+		gcenable();
+		eval(append(fn, list), NULL, 0);
 	}
+	RefEnd2(list, fn);
 }

From a91d2643afcba012fa97b6226b33ff36d8f85024 Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Fri, 29 Nov 2024 11:05:24 -0800
Subject: [PATCH 2/9] Don't print anything on sigint or sigpipe

---
 initial.es |  2 +-
 mksignal   | 11 +++--------
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/initial.es b/initial.es
index 638028b3..a8e50d19 100644
--- a/initial.es
+++ b/initial.es
@@ -582,7 +582,7 @@ if {~ <=$&primitives execfailure} {fn-%exec-failure = $&execfailure}
 #	status from an exec()ed binary.
 
 fn %print-status pid did status {
-	if {~ $did signaled} {
+	if {~ $did signaled && !~ $status (sigint sigpipe)} {
 		let (msg = <={if {$print-status-pid} {result $pid^': '} {result ''}}) {
 			msg = $msg^<={$&sigmessage $status}
 			if {~ $status *+core} {
diff --git a/mksignal b/mksignal
index cab97cb5..870733b8 100755
--- a/mksignal
+++ b/mksignal
@@ -34,12 +34,14 @@ sed -n '
 		mesg["SIGHUP"]		= "hangup"
 		mesg["SIGILL"]		= "illegal instruction"
 		mesg["SIGINFO"]		= "information request"
+		mesg["SIGINT"]		= "interrupt"
 		mesg["SIGIO"]		= "input/output possible"
 		mesg["SIGIOT"]		= "IOT instruction"
 		mesg["SIGKILL"]		= "killed"
 		mesg["SIGLOST"]		= "resource lost"
 		mesg["SIGLWP"]		= "lightweight process library signal"
 		mesg["SIGMIGRATE"]	= "migrate process"
+		mesg["SIGPIPE"]		= "broken pipe"
 		mesg["SIGPOLL"]		= "pollable event occurred"
 		mesg["SIGPROF"]		= "profiling timer alarm"
 		mesg["SIGPWR"]		= "power failure"
@@ -82,13 +84,6 @@ sed -n '
 		mesg["SIGVIRT"]		= "virtual time alarm"
 		mesg["SIGWINDOW"]	= "window size changed"
 
-
-		# set nomesg["SIGNAME"] to suppress message printing
-
-		nomesg["SIGINT"] = 1
-		nomesg["SIGPIPE"] = 1
-
-
 		# set ignore["SIGNAME"] to explicitly ignore a named signal (usually, this
 		# is just for things that look like signals but really are not)
 
@@ -117,7 +112,7 @@ sed -n '
 	sig[$1] == 0 && ignore[$1] == 0 {
 		sig[$1] = ++nsig
 		signame[nsig] = $1
-		if (mesg[$1] == "" && nomesg[$1] == 0) {
+		if (mesg[$1] == "") {
 			str = $3
 			for (i = 4; i <= NF; i++)
 				str = str " " $i

From 118efc7f55057737be1b5a3007a4c406d76814fd Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Sat, 30 Nov 2024 08:58:20 -0800
Subject: [PATCH 3/9] Add -n option to $&wait, corresponding with WNOHANG

---
 es.h       |  4 ++--
 prim-sys.c |  2 +-
 proc.c     | 45 +++++++++++++++++++++++++++++++--------------
 3 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/es.h b/es.h
index ea218575..4fd4cd63 100644
--- a/es.h
+++ b/es.h
@@ -226,8 +226,8 @@ extern int efork(Boolean parent, Boolean background);
 extern pid_t spgrp(pid_t pgid);
 extern int tctakepgrp(void);
 extern void initpgrp(void);
-extern int ewait(int pid, Boolean interruptible, void *rusage);
-#define	ewaitfor(pid)	ewait(pid, FALSE, NULL)
+extern int ewait(int pid, int opts, void *rusage);
+#define	ewaitfor(pid)	ewait(pid, 0, NULL)
 
 #if JOB_PROTECT
 extern void tcreturnpgrp(void);
diff --git a/prim-sys.c b/prim-sys.c
index a52b59b5..38942d34 100644
--- a/prim-sys.c
+++ b/prim-sys.c
@@ -323,7 +323,7 @@ PRIM(time) {
 	pid = efork(TRUE, FALSE);
 	if (pid == 0)
 		esexit(exitstatus(eval(lp, NULL, evalflags | eval_inchild)));
-	status = ewait(pid, FALSE, &r);
+	status = ewait(pid, 0, &r);
 	t1 = time(NULL);
 	SIGCHK();
 	printstatus(pid, status);
diff --git a/proc.c b/proc.c
index c12da2e6..4e3e328e 100644
--- a/proc.c
+++ b/proc.c
@@ -9,6 +9,9 @@
 #include <sys/resource.h>
 #endif
 
+#define	EWINTERRUPTIBLE	1
+#define	EWNOHANG	2
+
 Boolean hasforked = FALSE;
 
 typedef struct Proc Proc;
@@ -137,7 +140,7 @@ static void timesub(struct timeval *a, struct timeval *b, struct timeval *res) {
 #endif
 
 /* dowait -- a waitpid wrapper that gets rusage and interfaces with signals */
-static int dowait(int pid, int *statusp, void UNUSED *rusagep) {
+static int dowait(int pid, int opts, int *statusp, void UNUSED *rusagep) {
 	int n;
 #if HAVE_GETRUSAGE
 	static struct rusage ru_saved;
@@ -147,7 +150,7 @@ static int dowait(int pid, int *statusp, void UNUSED *rusagep) {
 	if (!setjmp(slowlabel)) {
 		slow = TRUE;
 		n = interrupted ? -2 :
-			waitpid(pid, statusp, 0);
+			waitpid(pid, statusp, (opts & EWNOHANG ? WNOHANG : 0));
 #if HAVE_GETRUSAGE
 		if (rusagep != NULL) {
 			struct rusage *rusage = (struct rusage *)rusagep;
@@ -185,21 +188,26 @@ static Proc *reap(int pid) {
 }
 
 /* ewait -- wait for a specific process to die, or any process if pid == -1 */
-extern int ewait(int pidarg, Boolean interruptible, void *rusage) {
+extern int ewait(int pidarg, int opts, void *rusage) {
 	int deadpid, status;
 	Proc *proc;
-	while ((deadpid = dowait(pidarg, &status, rusage)) == -1) {
+	while ((deadpid = dowait(pidarg, (opts & EWNOHANG), &status, rusage)) == -1) {
 		if (errno == ECHILD && pidarg > 0)
 			fail("es:ewait", "wait: %d is not a child of this shell", pidarg);
-		else if (errno != EINTR)
+		else if (errno == ECHILD && (opts & EWNOHANG) > 0) {
+			deadpid = 0;
+			break;
+		} else if (errno != EINTR)
 			fail("es:ewait", "wait: %s", esstrerror(errno));
-		if (interruptible)
+		if (opts & EWINTERRUPTIBLE)
 			SIGCHK();
 	}
-	proc = reap(deadpid);
 #if JOB_PROTECT
 	tctakepgrp();
 #endif
+	if (deadpid == 0) /* dowait(EWNOHANG) returned nothing */
+		return -1; /* FIXME: replace this with a better value! */
+	proc = reap(deadpid);
 	if (proc->background)
 		printstatus(proc->pid, status);
 	efree(proc);
@@ -221,20 +229,29 @@ PRIM(apids) {
 }
 
 PRIM(wait) {
-	int pid;
-	if (list == NULL)
-		pid = -1;
-	else if (list->next == NULL) {
+	int status, pid = -1, opts = EWINTERRUPTIBLE;
+	Ref(List *, lp, list);
+	if (lp != NULL && streq(getstr(lp->term), "-n")) {
+		opts = opts | EWNOHANG;
+		lp = lp->next;
+	}
+	if (lp != NULL) {
 		pid = atoi(getstr(list->term));
 		if (pid <= 0) {
 			fail("$&wait", "wait: %d: bad pid", pid);
 			NOTREACHED;
 		}
-	} else {
-		fail("$&wait", "usage: wait [pid]");
+		lp = lp->next;
+	}
+	if (lp != NULL) {
+		fail("$&wait", "usage: wait [-n] [pid]");
 		NOTREACHED;
 	}
-	return mklist(mkstr(mkstatus(ewait(pid, TRUE, NULL))), NULL);
+	RefEnd(lp);
+	status = ewait(pid, opts, NULL);
+	if (status == -1) /* FIXME: this will be a better value soon */
+		return NULL;
+	return mklist(mkstr(mkstatus(status)), NULL);
 }
 
 extern Dict *initprims_proc(Dict *primdict) {

From 7b423b69dea7c6bc082188f87eeaf82deb2c9035 Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Sat, 30 Nov 2024 09:35:43 -0800
Subject: [PATCH 4/9] Use $&sigmessage in %interactive-loop

---
 initial.es | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/initial.es b/initial.es
index a8e50d19..fe785b39 100644
--- a/initial.es
+++ b/initial.es
@@ -661,7 +661,7 @@ fn %interactive-loop {
 				$fn-%dispatch false
 			} {~ $e signal} {
 				if {!~ $type sigint sigterm sigquit} {
-					echo >[1=2] caught unexpected signal: $type
+					echo >[1=2] caught unexpected signal: $type: <={$&sigmessage $type}
 				}
 			} {
 				echo >[1=2] uncaught exception: $e $type $msg

From fff454e3163a5047d805bebb35d2b772e586ca62 Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Sat, 30 Nov 2024 10:19:44 -0800
Subject: [PATCH 5/9] Call printstatus() from ewait() and remove
 proc->background field

---
 es.h       |  2 +-
 eval.c     |  3 +--
 prim-io.c  | 16 ++++++----------
 prim-sys.c | 14 +++++---------
 proc.c     | 20 ++++++++------------
 5 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/es.h b/es.h
index 4fd4cd63..4913d278 100644
--- a/es.h
+++ b/es.h
@@ -222,7 +222,7 @@ extern char *checkexecutable(char *file);
 /* proc.c */
 
 extern Boolean hasforked;
-extern int efork(Boolean parent, Boolean background);
+extern int efork(Boolean parent);
 extern pid_t spgrp(pid_t pgid);
 extern int tctakepgrp(void);
 extern void initpgrp(void);
diff --git a/eval.c b/eval.c
index 43c6d2d3..f55a6f88 100644
--- a/eval.c
+++ b/eval.c
@@ -28,7 +28,7 @@ extern List *forkexec(char *file, List *list, Boolean inchild) {
 	Vector *env;
 	gcdisable();
 	env = mkenv();
-	pid = efork(!inchild, FALSE);
+	pid = efork(!inchild);
 	if (pid == 0) {
 		execve(file, vectorize(list)->vector, env->vector);
 		failexec(file, list);
@@ -41,7 +41,6 @@ extern List *forkexec(char *file, List *list, Boolean inchild) {
 		sigint_newline = TRUE;
 	} else
 		SIGCHK();
-	printstatus(pid, status);
 	return mklist(mkterm(mkstatus(status), NULL), NULL);
 }
 
diff --git a/prim-io.c b/prim-io.c
index a8d293a3..83c52935 100644
--- a/prim-io.c
+++ b/prim-io.c
@@ -141,7 +141,7 @@ static int pipefork(int p[2], int *extra) {
 		registerfd(extra, FALSE);
 
 	ExceptionHandler
-		pid = efork(TRUE, FALSE);
+		pid = efork(TRUE);
 	CatchExceptionIf (pid != 0, e)
 		unregisterfd(&p[0]);
 		unregisterfd(&p[1]);
@@ -205,7 +205,7 @@ PRIM(pipe) {
 	for (;; list = list->next) {
 		int p[2], pid;
 
-		pid = (list->next == NULL) ? efork(TRUE, FALSE) : pipefork(p, &inpipe);
+		pid = (list->next == NULL) ? efork(TRUE) : pipefork(p, &inpipe);
 
 		if (pid == 0) {		/* child */
 			if (inpipe != -1) {
@@ -237,7 +237,6 @@ PRIM(pipe) {
 		int pid = pids[--n];
 		Term *t;
 		int status = ewaitfor(pid);
-		printstatus(pid, status);
 		t = mkstr(mkstatus(status));
 		result = mklist(t, result);
 	} while (0 < n);
@@ -248,7 +247,7 @@ PRIM(pipe) {
 
 #if HAVE_DEV_FD
 PRIM(readfrom) {
-	int pid, p[2], status;
+	int pid, p[2];
 	Push push;
 
 	caller = "$&readfrom";
@@ -280,15 +279,14 @@ PRIM(readfrom) {
 	EndExceptionHandler
 
 	close(p[0]);
-	status = ewaitfor(pid);
-	printstatus(pid, status);
+	ewaitfor(pid);
 	varpop(&push);
 	RefEnd3(cmd, input, var);
 	RefReturn(lp);
 }
 
 PRIM(writeto) {
-	int pid, p[2], status;
+	int pid, p[2];
 	Push push;
 
 	caller = "$&writeto";
@@ -320,8 +318,7 @@ PRIM(writeto) {
 	EndExceptionHandler
 
 	close(p[1]);
-	status = ewaitfor(pid);
-	printstatus(pid, status);
+	ewaitfor(pid);
 	varpop(&push);
 	RefEnd3(cmd, output, var);
 	RefReturn(lp);
@@ -369,7 +366,6 @@ PRIM(backquote) {
 	lp = bqinput(sep, p[0]);
 	close(p[0]);
 	status = ewaitfor(pid);
-	printstatus(pid, status);
 	gcdisable();
 	lp = mklist(mkstr(mkstatus(status)), lp);
 	gcenable();
diff --git a/prim-sys.c b/prim-sys.c
index 38942d34..409d4008 100644
--- a/prim-sys.c
+++ b/prim-sys.c
@@ -36,7 +36,7 @@ PRIM(newpgrp) {
 }
 
 PRIM(background) {
-	int pid = efork(TRUE, TRUE);
+	int pid = efork(TRUE);
 	if (pid == 0) {
 #if JOB_PROTECT
 		/* job control safe version: put it in a new pgroup, if interactive. */
@@ -51,12 +51,11 @@ PRIM(background) {
 
 PRIM(fork) {
 	int pid, status;
-	pid = efork(TRUE, FALSE);
+	pid = efork(TRUE);
 	if (pid == 0)
 		esexit(exitstatus(eval(list, NULL, evalflags | eval_inchild)));
 	status = ewaitfor(pid);
 	SIGCHK();
-	printstatus(pid, status);
 	return mklist(mkstr(mkstatus(status)), NULL);
 }
 
@@ -320,13 +319,12 @@ PRIM(time) {
 
 	gc();	/* do a garbage collection first to ensure reproducible results */
 	t0 = time(NULL);
-	pid = efork(TRUE, FALSE);
+	pid = efork(TRUE);
 	if (pid == 0)
 		esexit(exitstatus(eval(lp, NULL, evalflags | eval_inchild)));
 	status = ewait(pid, 0, &r);
 	t1 = time(NULL);
 	SIGCHK();
-	printstatus(pid, status);
 
 	eprint(
 		"%6ldr %5ld.%ldu %5ld.%lds\t%L\n",
@@ -345,7 +343,7 @@ PRIM(time) {
 	Ref(List *, lp, list);
 
 	gc();	/* do a garbage collection first to ensure reproducible results */
-	pid = efork(TRUE, FALSE);
+	pid = efork(TRUE);
 	if (pid == 0) {
 		clock_t t0, t1;
 		struct tms tms;
@@ -355,14 +353,13 @@ PRIM(time) {
 			ticks = sysconf(_SC_CLK_TCK);
 
 		t0 = times(&tms);
-		pid = efork(TRUE, FALSE);
+		pid = efork(TRUE);
 		if (pid == 0)
 			esexit(exitstatus(eval(lp, NULL, evalflags | eval_inchild)));
 
 		status = ewaitfor(pid);
 		t1 = times(&tms);
 		SIGCHK();
-		printstatus(pid, status);
 
 		tms.tms_cutime += ticks / 20;
 		tms.tms_cstime += ticks / 20;
@@ -378,7 +375,6 @@ PRIM(time) {
 	}
 	status = ewaitfor(pid);
 	SIGCHK();
-	printstatus(pid, status);
 
 	RefEnd(lp);
 	return mklist(mkstr(mkstatus(status)), NULL);
diff --git a/proc.c b/proc.c
index 4e3e328e..6f560b95 100644
--- a/proc.c
+++ b/proc.c
@@ -17,7 +17,6 @@ Boolean hasforked = FALSE;
 typedef struct Proc Proc;
 struct Proc {
 	int pid;
-	Boolean background;
 	Proc *next, *prev;
 };
 
@@ -30,22 +29,21 @@ static pid_t tcpgid0;
 #endif
 
 /* mkproc -- create a Proc structure */
-extern Proc *mkproc(int pid, Boolean background) {
+extern Proc *mkproc(int pid) {
 	Proc *proc = ealloc(sizeof (Proc));
 	proc->next = proclist;
 	proc->pid = pid;
-	proc->background = background;
 	proc->prev = NULL;
 	return proc;
 }
 
 /* efork -- fork (if necessary) and clean up as appropriate */
-extern int efork(Boolean parent, Boolean background) {
+extern int efork(Boolean parent) {
 	if (parent) {
 		int pid = fork();
 		switch (pid) {
 		default: {	/* parent */
-			Proc *proc = mkproc(pid, background);
+			Proc *proc = mkproc(pid);
 			if (proclist != NULL)
 				proclist->prev = proc;
 			proclist = proc;
@@ -208,8 +206,7 @@ extern int ewait(int pidarg, int opts, void *rusage) {
 	if (deadpid == 0) /* dowait(EWNOHANG) returned nothing */
 		return -1; /* FIXME: replace this with a better value! */
 	proc = reap(deadpid);
-	if (proc->background)
-		printstatus(proc->pid, status);
+	printstatus(proc->pid, status);
 	efree(proc);
 	return status;
 }
@@ -219,11 +216,10 @@ extern int ewait(int pidarg, int opts, void *rusage) {
 PRIM(apids) {
 	Proc *p;
 	Ref(List *, lp, NULL);
-	for (p = proclist; p != NULL; p = p->next)
-		if (p->background) {
-			Term *t = mkstr(str("%d", p->pid));
-			lp = mklist(t, lp);
-		}
+	for (p = proclist; p != NULL; p = p->next) {
+		Term *t = mkstr(str("%d", p->pid));
+		lp = mklist(t, lp);
+	}
 	/* TODO: sort the return value, but by number? */
 	RefReturn(lp);
 }

From 6a96d1a9b39a71f5ae75b57facffd8700f4fb11c Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Sat, 30 Nov 2024 18:15:50 -0800
Subject: [PATCH 6/9] %print-status => %echo-status

---
 initial.es | 10 +++++-----
 status.c   |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/initial.es b/initial.es
index fe785b39..05ef5d04 100644
--- a/initial.es
+++ b/initial.es
@@ -578,12 +578,12 @@ fn %pathsearch name { access -n $name -1e -xf $path }
 
 if {~ <=$&primitives execfailure} {fn-%exec-failure = $&execfailure}
 
-#	The %print-status hook is used to print any potentially interesting
+#	The %echo-status hook is used to print any potentially interesting
 #	status from an exec()ed binary.
 
-fn %print-status pid did status {
+fn %echo-status pid did status {
 	if {~ $did signaled && !~ $status (sigint sigpipe)} {
-		let (msg = <={if {$print-status-pid} {result $pid^': '} {result ''}}) {
+		let (msg = <={if {$echo-status-pid} {result $pid^': '} {result ''}}) {
 			msg = $msg^<={$&sigmessage $status}
 			if {~ $status *+core} {
 				msg = $msg^'--core dumped'
@@ -593,10 +593,10 @@ fn %print-status pid did status {
 	}
 }
 
-print-status-pid = false
+echo-status-pid = false
 
 fn wait {
-	local (print-status-pid = true) $&wait $*
+	local (echo-status-pid = true) $&wait $*
 }
 
 #
diff --git a/status.c b/status.c
index c72c552b..2ddca3ce 100644
--- a/status.c
+++ b/status.c
@@ -65,7 +65,7 @@ extern char *mkstatus(int status) {
 
 /* printstatus -- print the status if we should */
 extern void printstatus(int pid, int status) {
-	Ref(List *, fn, varlookup("fn-%print-status", NULL));
+	Ref(List *, fn, varlookup("fn-%echo-status", NULL));
 	Ref(List *, list, NULL);
 	if (fn != NULL) {
 		gcdisable();

From b2609421e1e056fa1fbb0512fbcd4bc0547f5b6f Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Sat, 30 Nov 2024 21:35:26 -0800
Subject: [PATCH 7/9] Add new stuff to man page

---
 doc/es.1 | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/doc/es.1 b/doc/es.1
index 99690bd4..d8692ce3 100644
--- a/doc/es.1
+++ b/doc/es.1
@@ -1856,7 +1856,7 @@ as input to
 and executes its contents.
 The options are a subset of the invocation options for the shell (see below).
 .TP
-.Cr "access \fR[\fP-n \fIname\fP\fR]\fP \fR[\fP-1e\fR]\fP \fR[\fP-rwx\fR]\fP  \fR[\fP-fdcblsp\fR]\fP \fIpath ...\fP"
+.Cr "access \fR[\fP-n \fIname\fP\fR]\fP \fR[\fP-1e\fR]\fP \fR[\fP-rwx\fR]\fP \fR[\fP-fdcblsp\fR]\fP \fIpath ...\fP"
 Tests if the named paths are accessible according to the options presented.
 Normally,
 .Cr access
@@ -2192,7 +2192,7 @@ are specified,
 .Cr \-e
 is used.
 .TP
-.Cr "wait \fI\fR[\fPpid\fR]"
+.Cr "wait \fR[\fP-n\fR]\fP \fI\fR[\fPpid\fR]"
 Waits for the specified
 .IR pid ,
 which must have been started by
@@ -2200,6 +2200,11 @@ which must have been started by
 If no
 .I pid
 is specified, waits for any child process to exit.
+If
+.Cr \-n
+is specified and the process(es) to be waited for is (are) not ready
+at call time, returns immediately instead of blocking or throwing an
+error.
 .TP
 .Cr "whatis \fIprogram ...\fP"
 For each named
@@ -2293,6 +2298,19 @@ copied (via
 to file descriptor
 .IR newfd .
 .TP
+.Cr "%echo-status \fIpid did status\fP"
+Inspects the exit
+.I status
+of an exited (and waited-for) process
+.IR pid ,
+where
+.I did
+indicates if the process
+.Cr exited
+or was
+.Cr signaled ,
+and prints any interesting condition.
+.TP
 .Cr "%eval-noprint \fIcmd\fP"
 Run the command.
 (Passed as the argument to
@@ -2740,7 +2758,7 @@ variable, which signals to the
 library how much of the history file should be read into the in-memory
 history log.
 .PP
-Several primitives are not directly associated with other function.
+Several primitives are not directly associated with other functions.
 They are:
 .TP
 .Cr "$&collect"
@@ -2750,7 +2768,7 @@ The garbage collector in
 runs rather frequently;
 there should be no reason for a user to issue this command.
 .TP
-.Cr "$&noreturn \fIlambda args ...\fP"
+.Cr "$&noreturn \fIlambda args ..."
 Call the
 .IR lambda ,
 but in such a way that it does not catch the
@@ -2765,6 +2783,11 @@ and
 .Cr "&&" )
 can be implemented as lambdas rather than primitives.
 .TP
+.Cr "$&sigmessage"
+converts a signal name such as
+.Cr sigint
+to a short message describing the signal, used for error reporting.
+.TP
 .Cr "$&primitives"
 Returns a list of the names of es primitives.
 .TP

From a9b179c6f9529bdff118371175533845f18b21d2 Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Tue, 3 Dec 2024 11:10:59 -0800
Subject: [PATCH 8/9] Bugfix: allow `wait -n $pid` to actually work

---
 proc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/proc.c b/proc.c
index 6f560b95..8ea78fda 100644
--- a/proc.c
+++ b/proc.c
@@ -232,7 +232,7 @@ PRIM(wait) {
 		lp = lp->next;
 	}
 	if (lp != NULL) {
-		pid = atoi(getstr(list->term));
+		pid = atoi(getstr(lp->term));
 		if (pid <= 0) {
 			fail("$&wait", "wait: %d: bad pid", pid);
 			NOTREACHED;

From 29ce32ac0c77bf93a16c8fe7b5648d0f13ecb3d5 Mon Sep 17 00:00:00 2001
From: jpco <jack.p.conger@gmail.com>
Date: Mon, 3 Mar 2025 21:09:55 -0800
Subject: [PATCH 9/9] Cleanup

---
 proc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/proc.c b/proc.c
index 253a4f2a..c60ed650 100644
--- a/proc.c
+++ b/proc.c
@@ -117,7 +117,7 @@ extern Noreturn esexit(int code) {
 }
 #endif
 
-/* dowait -- a waitpid wrapper that gets rusage and interfaces with signals */
+/* dowait -- a waitpid wrapper that interfaces with signals */
 static int dowait(int pid, int opts, int *statusp) {
 	int n;
 	interrupted = FALSE;
@@ -171,8 +171,8 @@ extern int ewait(int pidarg, int opts) {
 #if JOB_PROTECT
 	tctakepgrp();
 #endif
-	if (deadpid == 0) /* dowait(EWNOHANG) returned nothing */
-		return -1; /* FIXME: replace this with a better value! */
+	if (deadpid == 0)	/* dowait(EWNOHANG) returned nothing */
+		return -1;
 	proc = reap(deadpid);
 	printstatus(proc->pid, status);
 	efree(proc);
@@ -213,7 +213,7 @@ PRIM(wait) {
 	}
 	RefEnd(lp);
 	status = ewait(pid, opts);
-	if (status == -1) /* FIXME: this will be a better value soon */
+	if (status == -1)	/* ewait got no exited processes */
 		return NULL;
 	return mklist(mkstr(mkstatus(status)), NULL);
 }