From 34be37860702e1ced96f642c44b692142b690889 Mon Sep 17 00:00:00 2001
From: Jack Conger <github@jpco.io>
Date: Sat, 28 Mar 2026 09:58:31 -0700
Subject: [PATCH 1/5] Create a $&readline primitive

---
 doc/es.1   | 11 +++++++++--
 es.h       |  1 +
 input.c    |  4 +++-
 prim-etc.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/doc/es.1 b/doc/es.1
index 9099905..28bc1bf 100644
--- a/doc/es.1
+++ b/doc/es.1
@@ -2795,11 +2795,18 @@ library:
 .ta 2i
 .Ds
 .ft \*(Cf
-resetterminal	sethistory
-setmaxhistorylength	writehistory
+readline	resetterminal
+sethistory	setmaxhistorylength
+writehistory
 .ft R
 .De
 .PP
+.Cr readline
+reads from standard input, using the
+.I readline
+library if its input is a terminal, taking a single optional prompt
+argument and returning a string containing the line it read or the
+empty list on EOF.
 .Cr sethistory
 and
 .Cr setmaxhistorylength
diff --git a/es.h b/es.h
index dd7e9c1..f47dde3 100644
--- a/es.h
+++ b/es.h
@@ -306,6 +306,7 @@ extern List *runstring(const char *str, const char *name, int flags);
 
 #if HAVE_READLINE
 extern Boolean resetterminal;
+extern char *callreadline(char *prompt);
 #endif
 
 
diff --git a/input.c b/input.c
index 1706ae3..c63e44d 100644
--- a/input.c
+++ b/input.c
@@ -79,7 +79,7 @@ extern void unget(Parser *p, int c) {
 
 #if HAVE_READLINE
 /* callreadline -- readline wrapper */
-static char *callreadline(char *prompt0) {
+extern char *callreadline(char *prompt0) {
 	char *r;
 	Ref(char *volatile, prompt, prompt0);
 	if (prompt == NULL)
@@ -118,6 +118,8 @@ static int fill(Input *in) {
 #if HAVE_READLINE
 	if (in->runflags & run_interactive && in->fd == 0) {
 		char *rlinebuf = NULL;
+		rl_instream = stdin;
+		rl_outstream = stdout;
 		do {
 			rlinebuf = callreadline(in->prompt);
 		} while (rlinebuf == NULL && errno == EINTR);
diff --git a/prim-etc.c b/prim-etc.c
index de6a0f7..cd7efb4 100644
--- a/prim-etc.c
+++ b/prim-etc.c
@@ -304,6 +304,49 @@ PRIM(setmaxevaldepth) {
 }
 
 #if HAVE_READLINE
+#include <readline/readline.h>
+
+PRIM(readline) {
+	char *line;
+	char *prompt = (list == NULL ? "" : getstr(list->term));
+	int input = fdmap(0);
+	if (list != NULL && list->next != NULL)
+		fail("$&readline", "usage: %read-line [prompt]");
+
+	if (!isatty(input)) {
+		list = prim("read", NULL, 0);
+		if (length(list) <= 1)
+			return list;
+		return mklist(mkstr(str("%L", list, "")), NULL);
+	}
+
+	rl_instream = fdopen(dup(input), "r");
+	rl_outstream = fdopen(dup(fdmap(1)), "w");
+
+	ExceptionHandler
+
+		do {
+			line = callreadline(prompt);
+		} while (line == NULL && errno == EINTR);
+
+	CatchException (e)
+
+		fclose(rl_instream);
+		fclose(rl_outstream);
+		throw(e);
+
+	EndExceptionHandler
+
+	fclose(rl_instream);
+	fclose(rl_outstream);
+
+	if (line == NULL)
+		return NULL;
+	list = mklist(mkstr(str("%s", line)), NULL);
+	efree(line);
+	return list;
+}
+
 PRIM(sethistory) {
 	if (list == NULL) {
 		sethistory(NULL);
@@ -373,6 +416,7 @@ extern Dict *initprims_etc(Dict *primdict) {
 	X(noreturn);
 	X(setmaxevaldepth);
 #if HAVE_READLINE
+	X(readline);
 	X(sethistory);
 	X(writehistory);
 	X(resetterminal);

From 5a973024e7dd31ec73f4b3172b9c5e05d3b2657f Mon Sep 17 00:00:00 2001
From: Jack Conger <github@jpco.io>
Date: Sat, 28 Mar 2026 10:32:55 -0700
Subject: [PATCH 2/5] Use stderr as rl_outstream in $&readline

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

diff --git a/prim-etc.c b/prim-etc.c
index cd7efb4..b3cae4c 100644
--- a/prim-etc.c
+++ b/prim-etc.c
@@ -321,7 +321,7 @@ PRIM(readline) {
 	}
 
 	rl_instream = fdopen(dup(input), "r");
-	rl_outstream = fdopen(dup(fdmap(1)), "w");
+	rl_outstream = fdopen(dup(fdmap(2)), "w");
 
 	ExceptionHandler
 

From e61a7fe1d173472612d65cc624da8a9f92a0159d Mon Sep 17 00:00:00 2001
From: Jack Conger <github@jpco.io>
Date: Sun, 29 Mar 2026 11:51:26 -0700
Subject: [PATCH 3/5] Add test cases including one for $&readline

---
 test/tests/read.es | 40 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/test/tests/read.es b/test/tests/read.es
index 32edee5..0080258 100644
--- a/test/tests/read.es
+++ b/test/tests/read.es
@@ -6,21 +6,51 @@ test 'null reading' {
 		echo first line	 > $tmp
 		./testrun 0	>> $tmp
 
+		let (first = (); second = ()) {
+			{
+				first = <=$&read
+				second = <=$&read
+			} < $tmp
+			assert {~ $first 'first line'} '$&read reads valid line'
+			assert {~ $second(1) 're'} '$&read reads line with zero (1)'
+			assert {~ $second(2) 'sult 6'} '$&read reads line with zero (2)'
+		}
+
 		let (first = (); second = ()) {
 			{
 				first = <=%read
 				second = <=%read
 			} < $tmp
-			assert {~ $first 'first line'} 'read reads valid line'
-			assert {~ $second 'result 6'} 'read reads line with zero'
+			assert {~ $first 'first line'} '%read reads valid line'
+			assert {~ $second 'result 6'} '%read reads line with zero'
+		}
+
+		let ((first second) = `` \n {
+			let (fl = ())
+			cat $tmp | {echo <=$&read; echo <=$&read}
+		}) {
+			assert {~ $first 'first line'} 'pipe $&read reads valid line'
+			assert {~ $second 're sult 6'} 'pipe $&read reads line with zero'
 		}
 
 		let ((first second) = `` \n {
 			let (fl = ())
-			cat $tmp | {echo <=%read^\n^<=%read}
+			cat $tmp | {echo <=%read; echo <=%read}
 		}) {
-			assert {~ $first 'first line'} 'pipe read reads valid line'
-			assert {~ $second 'result 6'} 'pipe read reads line with zero'
+			assert {~ $first 'first line'} 'pipe %read reads valid line'
+			assert {~ $second 'result 6'} 'pipe %read reads line with zero'
+		}
+
+		# TODO: $&readline should not be tested in this file
+		if {~ <=$&primitives readline} {
+			let (first = (); second = ()) {
+				{
+					first = <=$&readline
+					second = <=$&readline
+				} < $tmp
+				assert {~ $first 'first line'} 'read reads valid line'
+				assert {~ $second 'result 6'} 'read reads line with zero'
+			}
 		}
 	} {
 		rm -f $tmp

From 0a92459a1cd2c2d39d56a012e90ddb47b548270d Mon Sep 17 00:00:00 2001
From: Jack Conger <github@jpco.io>
Date: Sun, 29 Mar 2026 12:47:27 -0700
Subject: [PATCH 4/5] Remove $&read fallback in $&readline

Also do a better job at handling errors setting up the fds for readline.
---
 doc/es.1           |  5 ++---
 prim-etc.c         | 29 +++++++++++++++++++----------
 test/tests/read.es | 18 +++++++++++++++---
 3 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/doc/es.1 b/doc/es.1
index e967076..8d1f37c 100644
--- a/doc/es.1
+++ b/doc/es.1
@@ -2809,9 +2809,8 @@ writehistory
 .Cr readline
 reads from standard input, using the
 .I readline
-library if its input is a terminal, taking a single optional prompt
-argument and returning a string containing the line it read or the
-empty list on EOF.
+library, taking a single optional prompt argument and returning a string
+containing the line it read or the empty list on EOF.
 .Cr sethistory
 and
 .Cr setmaxhistorylength
diff --git a/prim-etc.c b/prim-etc.c
index b3cae4c..c6b1a39 100644
--- a/prim-etc.c
+++ b/prim-etc.c
@@ -306,22 +306,31 @@ PRIM(setmaxevaldepth) {
 #if HAVE_READLINE
 #include <readline/readline.h>
 
+static FILE *fdmapopen(int fd, const char *mode) {
+	FILE *f;
+	if ((fd = dup(fdmap(fd))) == -1)
+		fail("$&readline", "dup: %s", esstrerror(errno));
+	if ((f = fdopen(fd, mode)) == NULL) {
+		int err = errno;
+		close(fd);
+		fail("$&readline", "fdopen: %s", esstrerror(err));
+	}
+	return f;
+}
+
 PRIM(readline) {
 	char *line;
 	char *prompt = (list == NULL ? "" : getstr(list->term));
-	int input = fdmap(0);
 	if (list != NULL && list->next != NULL)
 		fail("$&readline", "usage: %read-line [prompt]");
 
-	if (!isatty(input)) {
-		list = prim("read", NULL, 0);
-		if (length(list) <= 1)
-			return list;
-		return mklist(mkstr(str("%L", list, "")), NULL);
-	}
-
-	rl_instream = fdopen(dup(input), "r");
-	rl_outstream = fdopen(dup(fdmap(2)), "w");
+	rl_instream = fdmapopen(0, "r");
+	ExceptionHandler
+		rl_outstream = fdmapopen(2, "w");
+	CatchException (e)
+		fclose(rl_instream);
+		throw(e);
+	EndExceptionHandler
 
 	ExceptionHandler
 
diff --git a/test/tests/read.es b/test/tests/read.es
index 0080258..605b03a 100644
--- a/test/tests/read.es
+++ b/test/tests/read.es
@@ -1,4 +1,4 @@
-#!/usr/local/bin/es
+# read.es -- test that reading handles edge cases
 
 test 'null reading' {
 	let (tmp = `{mktemp test-nul.XXXXXX})
@@ -41,13 +41,13 @@ test 'null reading' {
 			assert {~ $second 'result 6'} 'pipe %read reads line with zero'
 		}
 
-		# TODO: $&readline should not be tested in this file
+
 		if {~ <=$&primitives readline} {
 			let (first = (); second = ()) {
 				{
 					first = <=$&readline
 					second = <=$&readline
-				} < $tmp
+				} < $tmp >[2] /dev/null  # hush the echoing
 				assert {~ $first 'first line'} 'read reads valid line'
 				assert {~ $second 'result 6'} 'read reads line with zero'
 			}
@@ -56,3 +56,15 @@ test 'null reading' {
 		rm -f $tmp
 	}
 }
+
+test 'fd error handling' {
+	assert {catch @ {true}  {$&read <<< '' <[0=]; false}}
+	assert {catch @ {false} {$&read <<< '' >[1=]; true}}
+	assert {catch @ {false} {$&read <<< '' >[2=]; true}}
+
+	if {~ <=$&primitives readline} {
+		assert {catch @ {true}  {$&readline <<< '' <[0=]; false}}
+		assert {catch @ {false} {$&readline <<< '' >[1=]; true}}
+		assert {catch @ {true}  {$&readline <<< '' >[2=]; false}}
+	}
+}

From f8f9c16700a92d017b1c33308e5dada83853bf87 Mon Sep 17 00:00:00 2001
From: Jack Conger <github@jpco.io>
Date: Sun, 29 Mar 2026 14:32:55 -0700
Subject: [PATCH 5/5] Begin to consolidate readline logic

---
 Makefile.in |   9 +-
 es.h        |   9 +-
 history.c   | 113 ------------
 input.c     | 277 ------------------------------
 main.c      |   5 -
 prim-etc.c  | 101 -----------
 prim.c      |   3 +
 prim.h      |   3 +
 readline.c  | 482 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 9 files changed, 498 insertions(+), 504 deletions(-)
 create mode 100644 readline.c

diff --git a/Makefile.in b/Makefile.in
index bf98da9..ae2c253 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -53,13 +53,13 @@ HFILES	= config.h es.h gc.h input.h prim.h print.h sigmsgs.h \
 CFILES	= access.c closure.c conv.c dict.c eval.c except.c fd.c gc.c glob.c \
 	  glom.c input.c heredoc.c history.c list.c main.c match.c open.c opt.c \
 	  prim-ctl.c prim-etc.c prim-io.c prim-sys.c prim.c print.c proc.c \
-	  sigmsgs.c signal.c split.c status.c str.c syntax.c term.c token.c \
-	  tree.c util.c var.c vec.c version.c y.tab.c dump.c
+	  readline.c sigmsgs.c signal.c split.c status.c str.c syntax.c term.c \
+	  token.c tree.c util.c var.c vec.c version.c y.tab.c dump.c
 OFILES	= access.o closure.o conv.o dict.o eval.o except.o fd.o gc.o glob.o \
 	  glom.o input.o heredoc.o history.o list.o main.o match.o open.o opt.o \
 	  prim-ctl.o prim-etc.o prim-io.o prim-sys.o prim.o print.o proc.o \
-	  sigmsgs.o signal.o split.o status.o str.o syntax.o term.o token.o \
-	  tree.o util.o var.o vec.o version.o y.tab.o
+	  readline.o sigmsgs.o signal.o split.o status.o str.o syntax.o term.o \
+	  token.o tree.o util.o var.o vec.o version.o y.tab.o
 OTHER	= Makefile parse.y mksignal
 GEN	= esdump y.tab.h y.output sigmsgs.c initial.c version.h
 
@@ -147,6 +147,7 @@ prim-io.o : prim-io.c es.h config.h stdenv.h gc.h prim.h
 prim-sys.o : prim-sys.c es.h config.h stdenv.h prim.h
 print.o : print.c es.h config.h stdenv.h print.h
 proc.o : proc.c es.h config.h stdenv.h prim.h
+readline.o : readline.c es.h config.h stdenv.h prim.h
 signal.o : signal.c es.h config.h stdenv.h sigmsgs.h
 split.o : split.c es.h config.h stdenv.h gc.h
 status.o : status.c es.h config.h stdenv.h term.h
diff --git a/es.h b/es.h
index f47dde3..08f58b4 100644
--- a/es.h
+++ b/es.h
@@ -304,14 +304,13 @@ extern List *runstring(const char *str, const char *name, int flags);
 #define	run_printcmds		32	/* -x */
 #define	run_lisptrees		64	/* -L and defined(LISPTREES) */
 
+
 #if HAVE_READLINE
+/* readline.c */
+
 extern Boolean resetterminal;
 extern char *callreadline(char *prompt);
-#endif
-
 
-/* history.c */
-#if HAVE_READLINE
 extern void inithistory(void);
 
 extern void sethistory(char *file);
@@ -320,6 +319,8 @@ extern void setmaxhistorylength(int length);
 extern void checkhistory(void);
 #endif
 
+
+/* history.c */
 extern void newhistbuffer(void);
 extern void addhistbuffer(char c);
 extern char *dumphistbuffer(void);
diff --git a/history.c b/history.c
index 4d9d5a2..b4f4cec 100644
--- a/history.c
+++ b/history.c
@@ -18,21 +18,6 @@
 
 static Buffer *histbuffer = NULL;
 
-#if HAVE_READLINE
-#include <readline/history.h>
-
-Boolean reloadhistory = FALSE;
-static char *history;
-
-#if 0
-/* These split history file entries by timestamp, which allows readline to pick up
- * multi-line commands correctly across process boundaries.  Disabled by default,
- * because it leaves the history file itself kind of ugly. */
-static int history_write_timestamps = 1;
-static char history_comment_char = '#';
-#endif
-#endif
-
 
 /*
  * histbuffer -- build the history line during input and dump it as a gc-string
@@ -63,101 +48,3 @@ extern char *dumphistbuffer(void) {
 		s[len - 1] = '\0';
 	return s;
 }
-
-
-/*
- * history file
- */
-
-#if HAVE_READLINE
-static int sethistorylength = -1; /* unlimited */
-
-extern void setmaxhistorylength(int len) {
-	sethistorylength = len;
-}
-
-extern void loghistory(char *cmd) {
-	int err;
-	if (cmd == NULL)
-		return;
-	add_history(cmd);
-	if (history == NULL)
-		return;
-
-	if ((err = append_history(1, history))) {
-		eprint("history(%s): %s\n", history, esstrerror(err));
-		vardef("history", NULL, NULL);
-	}
-}
-
-static int count_history(void) {
-	int i, n, count = 0, fd = eopen(history, oOpen);
-	char buf[4096];
-	if (fd < 0)
-		return -1;
-	while ((n = read(fd, &buf, 4096)) != 0) {
-		if (n < 0) {
-			if (errno == EINTR) {
-				SIGCHK();
-				continue;
-			} else {
-				close(fd);
-				return -1;
-			}
-		}
-		for (i = 0; i < n; i++)
-			if (buf[i] == '\n')
-				count++;
-	}
-	close(fd);
-	return count;
-}
-
-static void reload_history(void) {
-	/* Attempt to populate readline history with new history file. */
-	if (history != NULL) {
-		int n = count_history() - sethistorylength;
-		if (sethistorylength < 0 || n < 0) n = 0;
-		read_history_range(history, n, -1);
-	}
-	using_history();
-
-	reloadhistory = FALSE;
-}
-
-extern void sethistory(char *file) {
-	if (reloadhistory)
-		reload_history();
-	reloadhistory = TRUE;
-	history = file;
-}
-
-extern void checkhistory(void) {
-	static int effectivelength = -1;
-	if (reloadhistory)
-		reload_history();
-	if (sethistorylength != effectivelength) {
-		switch (sethistorylength) {
-		case -1:
-			unstifle_history();
-			break;
-		case 0:
-			clear_history();
-			FALLTHROUGH;
-		default:
-			stifle_history(sethistorylength);
-		}
-		effectivelength = sethistorylength;
-	}
-}
-
-/*
- * initialization
- */
-
-/* inithistory -- called at dawn of time from main() */
-extern void inithistory(void) {
-	/* declare the global roots */
-	globalroot(&history);		/* history file */
-}
-#endif
diff --git a/input.c b/input.c
index c63e44d..9d08753 100644
--- a/input.c
+++ b/input.c
@@ -77,33 +77,6 @@ extern void unget(Parser *p, int c) {
 	p->unget[p->ungot++] = c;
 }
 
-#if HAVE_READLINE
-/* callreadline -- readline wrapper */
-extern char *callreadline(char *prompt0) {
-	char *r;
-	Ref(char *volatile, prompt, prompt0);
-	if (prompt == NULL)
-		prompt = ""; /* bug fix for readline 2.0 */
-	checkhistory();
-	if (resetterminal) {
-		rl_reset_terminal(NULL);
-		resetterminal = FALSE;
-	}
-	if (RL_ISSTATE(RL_STATE_INITIALIZED))
-		rl_reset_screen_size();
-	if (!sigsetjmp(slowlabel, 1)) {
-		slow = TRUE;
-		r = readline(prompt);
-	} else {
-		r = NULL;
-		errno = EINTR;
-	}
-	slow = FALSE;
-	SIGCHK();
-	RefEnd(prompt);
-	return r;
-}
-#endif
 
 
 static int fill(Input *in) {
@@ -381,253 +354,3 @@ extern Boolean isinteractive(void) {
 extern Boolean isfromfd(void) {
 	return input == NULL ? FALSE : (input->fd >= 0);
 }
-
-
-/*
- * readline integration.
- */
-#if HAVE_READLINE
-/* quote -- teach readline how to quote a word during completion.
- * prefix is prepended _before_ the quotes, such as: $'foo bar' */
-static char *quote(char *text, Boolean open, char *prefix, char *qp) {
-	char *quoted;
-	if (*qp != '\0' || strpbrk(text, rl_filename_quote_characters)) {
-		quoted = mprint("%s%#S", prefix, text);
-		if (open)
-			quoted[strlen(quoted)-1] = '\0';
-	} else {
-		quoted = mprint("%s%s", prefix, text);
-	}
-	efree(text);
-	return quoted;
-}
-
-/* unquote -- remove quotes from text and point *qp at the relevant quote char */
-static char *unquote(const char *text, char **qp) {
-	char *p, *r;
-	Boolean quoted = FALSE;
-
-	p = r = ealloc(strlen(text) + 1);
-	while ((*p = *text++)) {
-		if (*p == '\'') {
-			if (quoted && *text == '\'') {
-				p++;
-				text++;
-			} else {
-				quoted = !quoted;
-				if (quoted && qp != NULL)
-					*qp = p;
-			}
-		} else if (!quoted && *p == '\\') {
-			/* anything else won't be handled correctly by the completer */
-			if (*text == ' ' || *text == '\'')
-				*p++ = *text++;
-		} else
-			p++;
-	}
-	*p = '\0';
-	if (!quoted && qp != NULL)
-		*qp = p;
-	return r;
-}
-
-/* Unquote files to allow readline to detect which are directories. */
-static int unquote_for_stat(char **name) {
-	char *unquoted;
-	if (!strpbrk(*name, rl_filename_quote_characters))
-		return 0;
-
-	unquoted = unquote(*name, NULL);
-	efree(*name);
-	*name = unquoted;
-	return 1;
-}
-
-/* Find the start of the word to complete.  This uses the trick where we set rl_point
- * to the start of the word to indicate the start of the word.  For this to work,
- * rl_basic_quote_characters must be the empty string or else this function's result
- * is overwritten, and doing that means we have to reimplement basically all quoting
- * behavior manually. */
-static char *completion_start(void) {
-	int i, start = 0;
-	Boolean quoted = FALSE, backslash = FALSE;
-	for (i = 0; i < rl_point; i++) {
-		char c = rl_line_buffer[i];
-		if (backslash) {
-			backslash = FALSE;
-			continue;
-		}
-		if (c == '\'')
-			quoted = !quoted;
-		else if (!quoted && c == '\\')
-			backslash = TRUE;
-		else if (!quoted && strchr(rl_basic_word_break_characters, c))
-			start = i; /* keep possible '$' char in term */
-	}
-	rl_point = start;
-	return NULL;
-}
-
-/* Basic function to use an es List created by gen() to generate readline matches. */
-static char *list_completion(const char *text, int state, List *(*gen)(const char *)) {
-	static char **matches = NULL;
-	static int i, len;
-
-	if (!state) {
-		Vector *vm = vectorize(gen(text));
-		matches = vm->vector;
-		len = vm->count;
-		i = 0;
-	}
-
-	if (!matches || i >= len)
-		return NULL;
-
-	return mprint("%s", matches[i++]);
-}
-
-static char *var_completion(const char *text, int state) {
-	return list_completion(text, state, varswithprefix);
-}
-
-static char *prim_completion(const char *text, int state) {
-	return list_completion(text, state, primswithprefix);
-}
-
-static int matchcmp(const void *a, const void *b) {
-	return strcoll(*(const char **)a, *(const char **)b);
-}
-
-/* Pick out a completion to perform based on the string's prefix */
-rl_compentry_func_t *select_completion(const char *text, char **prefix) {
-	if (*text == '$') {
-		switch (text[1]) {
-		case '&':
-			*prefix = "$&";
-			return prim_completion;
-		case '^': *prefix = "$^"; break;
-		case '#': *prefix = "$#"; break;
-		default:  *prefix = "$";
-		}
-		return var_completion;
-	} else if (*text == '~' && !strchr(text, '/')) {
-		/* ~foo => username.  ~foo/bar gets completed as a filename. */
-		return rl_username_completion_function;
-	}
-	return rl_filename_completion_function;
-}
-
-static rl_compentry_func_t *completion_func = NULL;
-
-/* Top-level completion function.  If completion_func is set, performs that completion.
- * Otherwise, performs a completion based on the prefix of the text. */
-char **builtin_completion(const char *text, int UNUSED start, int UNUSED end) {
-	char **matches = NULL, *qp = NULL, *prefix = "";
-	/* Manually unquote the text, since we told readline not to. */
-	char *t = unquote(text, &qp);
-	rl_compentry_func_t *completion;
-
-	if (completion_func != NULL) {
-		completion = completion_func;
-		completion_func = NULL;
-	} else
-		completion = select_completion(text, &prefix);
-
-	matches = rl_completion_matches(t+strlen(prefix), completion);
-
-	/* Manually sort and then re-quote the matches. */
-	if (matches != NULL) {
-		size_t i, n;
-		for (n = 1; matches[n]; n++)
-			;
-		qsort(&matches[1], n - 1, sizeof(matches[0]), matchcmp);
-		matches[0] = quote(matches[0], n > 1, prefix, qp);
-		for (i = 1; i < n; i++)
-			matches[i] = quote(matches[i], FALSE, prefix, qp);
-	}
-
-	efree(t);
-
-	/* Since we had to sort and quote results ourselves, we disable the automatic
-	 * filename completion and sorting. */
-	rl_attempted_completion_over = 1;
-	rl_sort_completion_matches = 0;
-	return matches;
-}
-
-/* Unquote matches when displaying in a menu.  This wouldn't be necessary, if not for
- * menu-complete. */
-static void display_matches(char **matches, int num, int max) {
-	int i;
-	char **unquoted;
-
-	if (rl_completion_query_items > 0 && num >= rl_completion_query_items) {
-		int c;
-		rl_crlf();
-		fprintf(rl_outstream, "Display all %d possibilities? (y or n)", num);
-		fflush(rl_outstream);
-		c = rl_read_key();
-		if (c != 'y' && c != 'Y' && c != ' ') {
-			rl_crlf();
-			rl_forced_update_display();
-			return;
-		}
-	}
-
-	unquoted = ealloc(sizeof(char *) * (num + 2));
-	for (i = 0; matches[i]; i++)
-		unquoted[i] = unquote(matches[i], NULL);
-	unquoted[i] = NULL;
-
-	rl_display_match_list(unquoted, num, max);
-	rl_forced_update_display();
-
-	for (i = 0; unquoted[i]; i++)
-		efree(unquoted[i]);
-	efree(unquoted);
-}
-
-static int es_complete_filename(int UNUSED count, int UNUSED key) {
-	completion_func = rl_filename_completion_function;
-	return rl_complete_internal(rl_completion_mode(es_complete_filename));
-}
-
-static int es_complete_variable(int UNUSED count, int UNUSED key) {
-	completion_func = var_completion;
-	return rl_complete_internal(rl_completion_mode(es_complete_variable));
-}
-
-static int es_complete_primitive(int UNUSED count, int UNUSED key) {
-	completion_func = prim_completion;
-	return rl_complete_internal(rl_completion_mode(es_complete_primitive));
-}
-#endif /* HAVE_READLINE */
-
-
-/*
- * initialization
- */
-
-/* initinput -- called at dawn of time from main() */
-extern void initinput(void) {
-#if HAVE_READLINE
-	rl_readline_name = "es";
-
-	/* this word_break_characters excludes '&' due to primitive completion */
-	rl_basic_word_break_characters = " \t\n`$><=;|{()}";
-	rl_filename_quote_characters = " \t\n\\`'$><=;|&{()}";
-	rl_basic_quote_characters = "";
-	rl_special_prefixes = "$";
-
-	rl_completion_word_break_hook = completion_start;
-	rl_filename_stat_hook = unquote_for_stat;
-	rl_attempted_completion_function = builtin_completion;
-	rl_completion_display_matches_hook = display_matches;
-
-	rl_add_funmap_entry("es-complete-filename", es_complete_filename);
-	rl_add_funmap_entry("es-complete-variable", es_complete_variable);
-	rl_add_funmap_entry("es-complete-primitive", es_complete_primitive);
-	rl_bind_keyseq("\033/", es_complete_filename);
-	rl_bind_keyseq("\033$", es_complete_variable);
-#endif
-}
diff --git a/main.c b/main.c
index f8f19ad..623ec70 100644
--- a/main.c
+++ b/main.c
@@ -177,11 +177,6 @@ int main(int argc, char **argv0) {
 
 	ExceptionHandler
 		roothandler = &_localhandler;	/* unhygeinic */
-
-		initinput();
-#if HAVE_READLINE
-		inithistory();
-#endif
 		initprims();
 		initvars();
 
diff --git a/prim-etc.c b/prim-etc.c
index c6b1a39..60a9137 100644
--- a/prim-etc.c
+++ b/prim-etc.c
@@ -303,100 +303,6 @@ PRIM(setmaxevaldepth) {
 	RefReturn(lp);
 }
 
-#if HAVE_READLINE
-#include <readline/readline.h>
-
-static FILE *fdmapopen(int fd, const char *mode) {
-	FILE *f;
-	if ((fd = dup(fdmap(fd))) == -1)
-		fail("$&readline", "dup: %s", esstrerror(errno));
-	if ((f = fdopen(fd, mode)) == NULL) {
-		int err = errno;
-		close(fd);
-		fail("$&readline", "fdopen: %s", esstrerror(err));
-	}
-	return f;
-}
-
-PRIM(readline) {
-	char *line;
-	char *prompt = (list == NULL ? "" : getstr(list->term));
-	if (list != NULL && list->next != NULL)
-		fail("$&readline", "usage: %read-line [prompt]");
-
-	rl_instream = fdmapopen(0, "r");
-	ExceptionHandler
-		rl_outstream = fdmapopen(2, "w");
-	CatchException (e)
-		fclose(rl_instream);
-		throw(e);
-	EndExceptionHandler
-
-	ExceptionHandler
-
-		do {
-			line = callreadline(prompt);
-		} while (line == NULL && errno == EINTR);
-
-	CatchException (e)
-
-		fclose(rl_instream);
-		fclose(rl_outstream);
-		throw(e);
-
-	EndExceptionHandler
-
-	fclose(rl_instream);
-	fclose(rl_outstream);
-
-	if (line == NULL)
-		return NULL;
-	list = mklist(mkstr(str("%s", line)), NULL);
-	efree(line);
-	return list;
-}
-
-PRIM(sethistory) {
-	if (list == NULL) {
-		sethistory(NULL);
-		return NULL;
-	}
-	Ref(List *, lp, list);
-	sethistory(getstr(lp->term));
-	RefReturn(lp);
-}
-
-PRIM(writehistory) {
-	if (list == NULL || list->next != NULL)
-		fail("$&writehistory", "usage: $&writehistory command");
-	loghistory(getstr(list->term));
-	return NULL;
-}
-
-PRIM(setmaxhistorylength) {
-	char *s;
-	int n;
-	if (list == NULL) {
-		setmaxhistorylength(-1); /* unlimited */
-		return NULL;
-	}
-	if (list->next != NULL)
-		fail("$&setmaxhistorylength", "usage: $&setmaxhistorylength [limit]");
-	Ref(List *, lp, list);
-	n = (int)strtol(getstr(lp->term), &s, 0);
-	if (n < 0 || (s != NULL && *s != '\0'))
-		fail("$&setmaxhistorylength", "max-history-length must be set to a positive integer");
-	setmaxhistorylength(n);
-	RefReturn(lp);
-}
-
-PRIM(resetterminal) {
-	resetterminal = TRUE;
-	return ltrue;
-}
-#endif
-
-
 /*
  * initialization
  */
@@ -424,12 +330,5 @@ extern Dict *initprims_etc(Dict *primdict) {
 	X(exitonfalse);
 	X(noreturn);
 	X(setmaxevaldepth);
-#if HAVE_READLINE
-	X(readline);
-	X(sethistory);
-	X(writehistory);
-	X(resetterminal);
-	X(setmaxhistorylength);
-#endif
 	return primdict;
 }
diff --git a/prim.c b/prim.c
index aaf24c7..1dc5299 100644
--- a/prim.c
+++ b/prim.c
@@ -47,6 +47,9 @@ extern void initprims(void) {
 	prims = initprims_sys(prims);
 	prims = initprims_proc(prims);
 	prims = initprims_access(prims);
+#if HAVE_READLINE
+	prims = initprims_readline(prims);
+#endif
 
 #define	primdict prims
 	X(primitives);
diff --git a/prim.h b/prim.h
index de11f81..76416ca 100644
--- a/prim.h
+++ b/prim.h
@@ -19,3 +19,6 @@ extern Dict *initprims_etc(Dict *primdict);		/* prim-etc.c */
 extern Dict *initprims_sys(Dict *primdict);		/* prim-sys.c */
 extern Dict *initprims_proc(Dict *primdict);		/* proc.c */
 extern Dict *initprims_access(Dict *primdict);		/* access.c */
+#if HAVE_READLINE
+extern Dict *initprims_readline(Dict *primdict);	/* readline.c */
+#endif
diff --git a/readline.c b/readline.c
new file mode 100644
index 0000000..ff58dac
--- /dev/null
+++ b/readline.c
@@ -0,0 +1,482 @@
+/* readline.c -- readline primitives */
+
+#include "es.h"
+#include "prim.h"
+
+#if HAVE_READLINE
+
+#include <readline/readline.h>
+#include <readline/history.h>
+
+Boolean reloadhistory = FALSE;
+static char *history;
+
+#if 0
+/* These split history file entries by timestamp, which allows readline to pick up
+ * multi-line commands correctly across process boundaries.  Disabled by default,
+ * because it leaves the history file itself kind of ugly. */
+static int history_write_timestamps = 1;
+static char history_comment_char = '#';
+#endif
+
+/*
+ * history functions
+ */
+
+static int sethistorylength = -1; /* unlimited */
+
+extern void setmaxhistorylength(int len) {
+	sethistorylength = len;
+}
+
+extern void loghistory(char *cmd) {
+	int err;
+	if (cmd == NULL)
+		return;
+	add_history(cmd);
+	if (history == NULL)
+		return;
+
+	if ((err = append_history(1, history))) {
+		eprint("history(%s): %s\n", history, esstrerror(err));
+		vardef("history", NULL, NULL);
+	}
+}
+
+static int count_history(void) {
+	int i, n, count = 0, fd = eopen(history, oOpen);
+	char buf[4096];
+	if (fd < 0)
+		return -1;
+	while ((n = read(fd, &buf, 4096)) != 0) {
+		if (n < 0) {
+			if (errno == EINTR) {
+				SIGCHK();
+				continue;
+			} else {
+				close(fd);
+				return -1;
+			}
+		}
+		for (i = 0; i < n; i++)
+			if (buf[i] == '\n')
+				count++;
+	}
+	close(fd);
+	return count;
+}
+
+static void reload_history(void) {
+	/* Attempt to populate readline history with new history file. */
+	if (history != NULL) {
+		int n = count_history() - sethistorylength;
+		if (sethistorylength < 0 || n < 0) n = 0;
+		read_history_range(history, n, -1);
+	}
+	using_history();
+
+	reloadhistory = FALSE;
+}
+
+extern void sethistory(char *file) {
+	if (reloadhistory)
+		reload_history();
+	reloadhistory = TRUE;
+	history = file;
+}
+
+extern void checkhistory(void) {
+	static int effectivelength = -1;
+	if (reloadhistory)
+		reload_history();
+	if (sethistorylength != effectivelength) {
+		switch (sethistorylength) {
+		case -1:
+			unstifle_history();
+			break;
+		case 0:
+			clear_history();
+			FALLTHROUGH;
+		default:
+			stifle_history(sethistorylength);
+		}
+		effectivelength = sethistorylength;
+	}
+}
+
+
+/*
+ * readline library functions
+ */
+
+/* quote -- teach readline how to quote a word during completion.
+ * prefix is prepended _before_ the quotes, such as: $'foo bar' */
+static char *quote(char *text, Boolean open, char *prefix, char *qp) {
+	char *quoted;
+	if (*qp != '\0' || strpbrk(text, rl_filename_quote_characters)) {
+		quoted = mprint("%s%#S", prefix, text);
+		if (open)
+			quoted[strlen(quoted)-1] = '\0';
+	} else {
+		quoted = mprint("%s%s", prefix, text);
+	}
+	efree(text);
+	return quoted;
+}
+
+/* unquote -- remove quotes from text and point *qp at the relevant quote char */
+static char *unquote(const char *text, char **qp) {
+	char *p, *r;
+	Boolean quoted = FALSE;
+
+	p = r = ealloc(strlen(text) + 1);
+	while ((*p = *text++)) {
+		if (*p == '\'') {
+			if (quoted && *text == '\'') {
+				p++;
+				text++;
+			} else {
+				quoted = !quoted;
+				if (quoted && qp != NULL)
+					*qp = p;
+			}
+		} else if (!quoted && *p == '\\') {
+			/* anything else won't be handled correctly by the completer */
+			if (*text == ' ' || *text == '\'')
+				*p++ = *text++;
+		} else
+			p++;
+	}
+	*p = '\0';
+	if (!quoted && qp != NULL)
+		*qp = p;
+	return r;
+}
+
+/* Unquote files to allow readline to detect which are directories. */
+static int unquote_for_stat(char **name) {
+	char *unquoted;
+	if (!strpbrk(*name, rl_filename_quote_characters))
+		return 0;
+
+	unquoted = unquote(*name, NULL);
+	efree(*name);
+	*name = unquoted;
+	return 1;
+}
+
+/* Find the start of the word to complete.  This uses the trick where we set rl_point
+ * to the start of the word to indicate the start of the word.  For this to work,
+ * rl_basic_quote_characters must be the empty string or else this function's result
+ * is overwritten, and doing that means we have to reimplement basically all quoting
+ * behavior manually. */
+static char *completion_start(void) {
+	int i, start = 0;
+	Boolean quoted = FALSE, backslash = FALSE;
+	for (i = 0; i < rl_point; i++) {
+		char c = rl_line_buffer[i];
+		if (backslash) {
+			backslash = FALSE;
+			continue;
+		}
+		if (c == '\'')
+			quoted = !quoted;
+		else if (!quoted && c == '\\')
+			backslash = TRUE;
+		else if (!quoted && strchr(rl_basic_word_break_characters, c))
+			start = i; /* keep possible '$' char in term */
+	}
+	rl_point = start;
+	return NULL;
+}
+
+/* Basic function to use an es List created by gen() to generate readline matches. */
+static char *list_completion(const char *text, int state, List *(*gen)(const char *)) {
+	static char **matches = NULL;
+	static int i, len;
+
+	if (!state) {
+		Vector *vm = vectorize(gen(text));
+		matches = vm->vector;
+		len = vm->count;
+		i = 0;
+	}
+
+	if (!matches || i >= len)
+		return NULL;
+
+	return mprint("%s", matches[i++]);
+}
+
+static char *var_completion(const char *text, int state) {
+	return list_completion(text, state, varswithprefix);
+}
+
+static char *prim_completion(const char *text, int state) {
+	return list_completion(text, state, primswithprefix);
+}
+
+static int matchcmp(const void *a, const void *b) {
+	return strcoll(*(const char **)a, *(const char **)b);
+}
+
+/* Pick out a completion to perform based on the string's prefix */
+rl_compentry_func_t *select_completion(const char *text, char **prefix) {
+	if (*text == '$') {
+		switch (text[1]) {
+		case '&':
+			*prefix = "$&";
+			return prim_completion;
+		case '^': *prefix = "$^"; break;
+		case '#': *prefix = "$#"; break;
+		default:  *prefix = "$";
+		}
+		return var_completion;
+	} else if (*text == '~' && !strchr(text, '/')) {
+		/* ~foo => username.  ~foo/bar gets completed as a filename. */
+		return rl_username_completion_function;
+	}
+	return rl_filename_completion_function;
+}
+
+static rl_compentry_func_t *completion_func = NULL;
+
+/* Top-level completion function.  If completion_func is set, performs that completion.
+ * Otherwise, performs a completion based on the prefix of the text. */
+char **builtin_completion(const char *text, int UNUSED start, int UNUSED end) {
+	char **matches = NULL, *qp = NULL, *prefix = "";
+	/* Manually unquote the text, since we told readline not to. */
+	char *t = unquote(text, &qp);
+	rl_compentry_func_t *completion;
+
+	if (completion_func != NULL) {
+		completion = completion_func;
+		completion_func = NULL;
+	} else
+		completion = select_completion(text, &prefix);
+
+	matches = rl_completion_matches(t+strlen(prefix), completion);
+
+	/* Manually sort and then re-quote the matches. */
+	if (matches != NULL) {
+		size_t i, n;
+		for (n = 1; matches[n]; n++)
+			;
+		qsort(&matches[1], n - 1, sizeof(matches[0]), matchcmp);
+		matches[0] = quote(matches[0], n > 1, prefix, qp);
+		for (i = 1; i < n; i++)
+			matches[i] = quote(matches[i], FALSE, prefix, qp);
+	}
+
+	efree(t);
+
+	/* Since we had to sort and quote results ourselves, we disable the automatic
+	 * filename completion and sorting. */
+	rl_attempted_completion_over = 1;
+	rl_sort_completion_matches = 0;
+	return matches;
+}
+
+/* Unquote matches when displaying in a menu.  This wouldn't be necessary, if not for
+ * menu-complete. */
+static void display_matches(char **matches, int num, int max) {
+	int i;
+	char **unquoted;
+
+	if (rl_completion_query_items > 0 && num >= rl_completion_query_items) {
+		int c;
+		rl_crlf();
+		fprintf(rl_outstream, "Display all %d possibilities? (y or n)", num);
+		fflush(rl_outstream);
+		c = rl_read_key();
+		if (c != 'y' && c != 'Y' && c != ' ') {
+			rl_crlf();
+			rl_forced_update_display();
+			return;
+		}
+	}
+
+	unquoted = ealloc(sizeof(char *) * (num + 2));
+	for (i = 0; matches[i]; i++)
+		unquoted[i] = unquote(matches[i], NULL);
+	unquoted[i] = NULL;
+
+	rl_display_match_list(unquoted, num, max);
+	rl_forced_update_display();
+
+	for (i = 0; unquoted[i]; i++)
+		efree(unquoted[i]);
+	efree(unquoted);
+}
+
+static int es_complete_filename(int UNUSED count, int UNUSED key) {
+	completion_func = rl_filename_completion_function;
+	return rl_complete_internal(rl_completion_mode(es_complete_filename));
+}
+
+static int es_complete_variable(int UNUSED count, int UNUSED key) {
+	completion_func = var_completion;
+	return rl_complete_internal(rl_completion_mode(es_complete_variable));
+}
+
+static int es_complete_primitive(int UNUSED count, int UNUSED key) {
+	completion_func = prim_completion;
+	return rl_complete_internal(rl_completion_mode(es_complete_primitive));
+}
+
+/* callreadline -- readline wrapper */
+extern char *callreadline(char *prompt0) {
+	char *r;
+	Ref(char *volatile, prompt, prompt0);
+	if (prompt == NULL)
+		prompt = ""; /* bug fix for readline 2.0 */
+	checkhistory();
+	if (resetterminal) {
+		rl_reset_terminal(NULL);
+		resetterminal = FALSE;
+	}
+	if (RL_ISSTATE(RL_STATE_INITIALIZED))
+		rl_reset_screen_size();
+	if (!sigsetjmp(slowlabel, 1)) {
+		slow = TRUE;
+		r = readline(prompt);
+	} else {
+		r = NULL;
+		errno = EINTR;
+	}
+	slow = FALSE;
+	SIGCHK();
+	RefEnd(prompt);
+	return r;
+}
+
+static FILE *fdmapopen(int fd, const char *mode) {
+	FILE *f;
+	if ((fd = dup(fdmap(fd))) == -1)
+		fail("$&readline", "dup: %s", esstrerror(errno));
+	if ((f = fdopen(fd, mode)) == NULL) {
+		int err = errno;
+		close(fd);
+		fail("$&readline", "fdopen: %s", esstrerror(err));
+	}
+	return f;
+}
+
+
+/*
+ * primitive interface
+ */
+
+PRIM(readline) {
+	char *line;
+	char *prompt = (list == NULL ? "" : getstr(list->term));
+	if (list != NULL && list->next != NULL)
+		fail("$&readline", "usage: %read-line [prompt]");
+
+	rl_instream = fdmapopen(0, "r");
+	ExceptionHandler
+		rl_outstream = fdmapopen(2, "w");
+	CatchException (e)
+		fclose(rl_instream);
+		throw(e);
+	EndExceptionHandler
+
+	ExceptionHandler
+
+		do {
+			line = callreadline(prompt);
+		} while (line == NULL && errno == EINTR);
+
+	CatchException (e)
+
+		fclose(rl_instream);
+		fclose(rl_outstream);
+		throw(e);
+
+	EndExceptionHandler
+
+	fclose(rl_instream);
+	fclose(rl_outstream);
+
+	if (line == NULL)
+		return NULL;
+	list = mklist(mkstr(str("%s", line)), NULL);
+	efree(line);
+	return list;
+}
+
+PRIM(sethistory) {
+	if (list == NULL) {
+		sethistory(NULL);
+		return NULL;
+	}
+	Ref(List *, lp, list);
+	sethistory(getstr(lp->term));
+	RefReturn(lp);
+}
+
+PRIM(writehistory) {
+	if (list == NULL || list->next != NULL)
+		fail("$&writehistory", "usage: $&writehistory command");
+	loghistory(getstr(list->term));
+	return NULL;
+}
+
+PRIM(setmaxhistorylength) {
+	char *s;
+	int n;
+	if (list == NULL) {
+		setmaxhistorylength(-1); /* unlimited */
+		return NULL;
+	}
+	if (list->next != NULL)
+		fail("$&setmaxhistorylength", "usage: $&setmaxhistorylength [limit]");
+	Ref(List *, lp, list);
+	n = (int)strtol(getstr(lp->term), &s, 0);
+	if (n < 0 || (s != NULL && *s != '\0'))
+		fail("$&setmaxhistorylength", "max-history-length must be set to a positive integer");
+	setmaxhistorylength(n);
+	RefReturn(lp);
+}
+
+PRIM(resetterminal) {
+	resetterminal = TRUE;
+	return ltrue;
+}
+
+
+/*
+ * initialization
+ */
+
+extern Dict *initprims_readline(Dict *primdict) {
+	rl_readline_name = "es";
+
+	/* this word_break_characters excludes '&' due to primitive completion */
+	rl_basic_word_break_characters = " \t\n`$><=;|{()}";
+	rl_filename_quote_characters = " \t\n\\`'$><=;|&{()}";
+	rl_basic_quote_characters = "";
+	rl_special_prefixes = "$";
+
+	rl_completion_word_break_hook = completion_start;
+	rl_filename_stat_hook = unquote_for_stat;
+	rl_attempted_completion_function = builtin_completion;
+	rl_completion_display_matches_hook = display_matches;
+
+	rl_add_funmap_entry("es-complete-filename", es_complete_filename);
+	rl_add_funmap_entry("es-complete-variable", es_complete_variable);
+	rl_add_funmap_entry("es-complete-primitive", es_complete_primitive);
+	rl_bind_keyseq("\033/", es_complete_filename);
+	rl_bind_keyseq("\033$", es_complete_variable);
+
+	globalroot(&history);		/* history file */
+
+	X(readline);
+	X(sethistory);
+	X(writehistory);
+	X(resetterminal);
+	X(setmaxhistorylength);
+
+	return primdict;
+}
+#endif