Add sh(1) prompt variable expansion.

Implement profile(5) and shrc(5) in sh(1).
Add sh(1) history builtin.
2022-11-20 22:15:51 +01:00 · 2022-11-19 18:01:30 +01:00 · 2022-11-19 18:01:30 +01:00 · 2022-11-19 18:01:30 +01:00 · 2022-11-16 21:10:46 +01:00 · 2022-11-16 21:10:46 +01:00
17 changed files with 977 additions and 240 deletions
--- a/init/init.c
+++ b/init/init.c
@ -440,7 +440,8 @@ static bool log_open(struct log* log)
 	log->fd = open(log->path, logflags, log->file_mode);
 	if ( log->fd < 0 )
 	{
-		log_error(log, "", NULL);
+		if ( errno != EROFS )
+			log_error(log, "", NULL);
 		// Don't block daemon startup on read-only filesystems.
 		return errno == EROFS;
 	}
--- a/kernel/gpu/bga/bga.cpp
+++ b/kernel/gpu/bga/bga.cpp
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2014, 2016, 2017 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2012, 2014, 2016, 2017, 2022 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
@ -238,6 +238,7 @@ bool BGADevice::Initialize()
 	Video::ConfigureDevice(this);

 #if defined(__i386__) || defined(__x86_64__)
+
 	if ( guest_additions )
 		guest_additions->ReadyVideoDevice(device_index);
 #endif
@ -609,24 +610,24 @@ static void TryInitializeDevice(uint32_t devaddr)
 	}
 }

+static bool OnDevice(uint32_t devaddr, const pciid_t*, const pcitype_t*, void*,
+                     void*)
+{
+	TryInitializeDevice(devaddr);
+	return true;
+}
+
 void Init()
 {
-	pcifind_t bga_pcifind;
-	memset(&bga_pcifind, 255, sizeof(bga_pcifind));
-	bga_pcifind.vendorid = 0x1234;
-	bga_pcifind.deviceid = 0x1111;
+	pcifind_t patterns[2];
+	memset(&patterns[0], 255, sizeof(patterns[0]));
+	patterns[0].vendorid = 0x1234;
+	patterns[0].deviceid = 0x1111;
+	memset(&patterns[1], 255, sizeof(patterns[1]));
+	patterns[1].vendorid = 0x80EE;
+	patterns[1].deviceid = 0xBEEF;

-	uint32_t devaddr = 0;
-	while ( (devaddr = PCI::SearchForDevices(bga_pcifind, devaddr)) )
-		TryInitializeDevice(devaddr);
-
-	memset(&bga_pcifind, 255, sizeof(bga_pcifind));
-	bga_pcifind.vendorid = 0x80EE;
-	bga_pcifind.deviceid = 0xBEEF;
-
-	devaddr = 0;
-	while ( (devaddr = PCI::SearchForDevices(bga_pcifind, devaddr)) )
-		TryInitializeDevice(devaddr);
+	PCI::Search(OnDevice, NULL, patterns, 2);
 }

 } // namespace BGA
--- a/login/login.c
+++ b/login/login.c
@ -214,13 +214,16 @@ bool login(const char* username)
 	int pipe_fds[2];
 	if ( pipe2(pipe_fds, O_CLOEXEC) < 0 )
 		return false;
+	char* login_shell;
+	if ( asprintf(&login_shell, "-%s", pwd->pw_shell) < 0 )
+		return close(pipe_fds[0]), close(pipe_fds[1]), false;
 	sigset_t oldset, sigttou;
 	sigemptyset(&sigttou);
 	sigaddset(&sigttou, SIGTTOU);
 	sigprocmask(SIG_BLOCK, &sigttou, &oldset);
 	pid_t child_pid = fork();
 	if ( child_pid < 0 )
-		return close(pipe_fds[0]), close(pipe_fds[1]), false;
+		return free(login_shell), close(pipe_fds[0]), close(pipe_fds[1]), false;
 	if ( child_pid == 0 )
 	{
 		sigdelset(&oldset, SIGINT);
@ -253,10 +256,11 @@ bool login(const char* username)
 		 errno != ENOENT && errno != EACCES) ||
 		(execlp("/etc/session", "/etc/session", (const char*) NULL) < 0 &&
 		 errno != ENOENT && errno != EACCES) ||
-		execlp(pwd->pw_shell, pwd->pw_shell, (const char*) NULL));
+		execlp(pwd->pw_shell, login_shell, (const char*) NULL));
 		write(pipe_fds[1], &errno, sizeof(errno));
 		_exit(127);
 	}
+	free(login_shell);
 	close(pipe_fds[1]);
 	int errnum;
 	if ( readall(pipe_fds[0], &errnum, sizeof(errnum)) < (ssize_t) sizeof(errnum) )
--- a/ports/dash/dash.patch
+++ b/ports/dash/dash.patch
@ -1,7 +1,7 @@
 diff -Paur --no-dereference -- dash.upstream/src/cd.c dash/src/cd.c
 --- dash.upstream/src/cd.c
 +++ dash/src/cd.c
-@@ -252,7 +252,7 @@
+@@ -268,7 +268,7 @@
 STATIC char *
 getpwd()
 {
@ -30,7 +30,24 @@ diff -Paur --no-dereference -- dash.upstream/src/exec.c dash/src/exec.c
 +#endif
 }
 
- 
+ static const char *legal_pathopt(const char *opt, const char *term, int magic)
+diff -Paur --no-dereference -- dash.upstream/src/expand.c dash/src/expand.c
+--- dash.upstream/src/expand.c
+++ dash/src/expand.c
+@@ -44,6 +44,13 @@
+ #include <stdio.h>
+ #include <inttypes.h>
+ #include <limits.h>
+/* PATCH: Sortix does not currently have maximum filename or path length */
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+#ifndef NAME_MAX
+#define NAME_MAX 255
+#endif
+ #include <string.h>
+ #ifdef HAVE_FNMATCH
+ #include <fnmatch.h>
 diff -Paur --no-dereference -- dash.upstream/src/histedit.c dash/src/histedit.c
 --- dash.upstream/src/histedit.c
 +++ dash/src/histedit.c
@ -53,7 +70,7 @@ diff -Paur --no-dereference -- dash.upstream/src/jobs.c dash/src/jobs.c
 #ifdef BSD
 #include <sys/wait.h>
 #include <sys/time.h>
-@@ -207,7 +206,7 @@
+@@ -212,7 +211,7 @@
 				mflag = on = 0;
 				goto close;
 			}
@ -62,7 +79,7 @@ diff -Paur --no-dereference -- dash.upstream/src/jobs.c dash/src/jobs.c
 				break;
 			killpg(0, SIGTTIN);
 		} while (1);
-@@ -457,7 +456,7 @@
+@@ -461,7 +460,7 @@
 
 	if (mode & SHOW_PGID) {
 		/* just output process (group) id of pipeline */
@ -71,7 +88,7 @@ diff -Paur --no-dereference -- dash.upstream/src/jobs.c dash/src/jobs.c
 		return;
 	}
 
-@@ -470,7 +469,7 @@
+@@ -474,7 +473,7 @@
 		s[col - 2] = '-';
 
 	if (mode & SHOW_PID)
@ -80,7 +97,7 @@ diff -Paur --no-dereference -- dash.upstream/src/jobs.c dash/src/jobs.c
 
 	psend = ps + jp->nprocs;
 
-@@ -490,7 +489,7 @@
+@@ -494,7 +493,7 @@
 
 	do {
 		/* for each process */
@ -89,43 +106,57 @@ diff -Paur --no-dereference -- dash.upstream/src/jobs.c dash/src/jobs.c
 
 start:
 		outfmt(
-@@ -1136,7 +1135,7 @@
+@@ -971,7 +970,7 @@
+ 	sigblockall(NULL);
+ 	vforked++;
 
+-	pid = vfork();
+	pid = fork();
+ 
+ 	if (!pid) {
+ 		forkchild(jp, n, FORK_FG);
+@@ -1179,7 +1178,7 @@
 	do {
 		gotsigchld = 0;
-		err = wait3(status, flags, NULL);
-+		err = waitpid(-1, status, flags);
- 		if (err || !block)
- 			break;
+ 		do
+-			err = wait3(status, flags, NULL);
+			err = waitpid(-1, status, flags);
+ 		while (err < 0 && errno == EINTR);
 
+ 		if (err || (err = -!block))
 diff -Paur --no-dereference -- dash.upstream/src/Makefile.in dash/src/Makefile.in
 --- dash.upstream/src/Makefile.in
 +++ dash/src/Makefile.in
-@@ -170,9 +170,9 @@
- AM_CFLAGS = $(COMMON_CFLAGS)
- AM_CPPFLAGS = $(COMMON_CPPFLAGS)
- AM_CFLAGS_FOR_BUILD = -g -O2 $(COMMON_CFLAGS) 
-AM_CPPFLAGS_FOR_BUILD = $(COMMON_CPPFLAGS)
-+AM_CPPFLAGS_FOR_BUILD = -DBSD=1 -DSHELL -DIFS_BROKEN
- COMPILE_FOR_BUILD = \
-	$(CC_FOR_BUILD) $(DEFAULT_INCLUDES) $(AM_CPPFLAGS_FOR_BUILD) \
-+	unset HOST_SYSTEM_ROOT && $(CC_FOR_BUILD) $(DEFAULT_INCLUDES) $(AM_CPPFLAGS_FOR_BUILD) \
- 	$(CPPFLAGS_FOR_BUILD) \
- 	$(AM_CFLAGS_FOR_BUILD) $(CFLAGS_FOR_BUILD) 
- 
-@@ -542,7 +542,11 @@
- 
- info-am:
- 
-install-data-am: install-man
-+install-data-am: install-man install-proper-shells
-+
-+install-proper-shells:
-+	mkdir -p "$(DESTDIR)$(sysconfdir)/proper-shells"
-+	echo dash > "$(DESTDIR)$(sysconfdir)/proper-shells/dash"
- 
- install-dvi: install-dvi-am
- 
+@@ -669,12 +669,14 @@
+ 		-rm -f ./$(DEPDIR)/alias.Po
+ 	-rm -f ./$(DEPDIR)/arith_yacc.Po
+ 	-rm -f ./$(DEPDIR)/arith_yylex.Po
+	-rm -f ./$(DEPDIR)/builtins.Po
+ 	-rm -f ./$(DEPDIR)/cd.Po
+ 	-rm -f ./$(DEPDIR)/error.Po
+ 	-rm -f ./$(DEPDIR)/eval.Po
+ 	-rm -f ./$(DEPDIR)/exec.Po
+ 	-rm -f ./$(DEPDIR)/expand.Po
+ 	-rm -f ./$(DEPDIR)/histedit.Po
+	-rm -f ./$(DEPDIR)/init.Po
+ 	-rm -f ./$(DEPDIR)/input.Po
+ 	-rm -f ./$(DEPDIR)/jobs.Po
+ 	-rm -f ./$(DEPDIR)/mail.Po
+@@ -682,11 +684,14 @@
+ 	-rm -f ./$(DEPDIR)/memalloc.Po
+ 	-rm -f ./$(DEPDIR)/miscbltin.Po
+ 	-rm -f ./$(DEPDIR)/mystring.Po
+	-rm -f ./$(DEPDIR)/nodes.Po
+ 	-rm -f ./$(DEPDIR)/options.Po
+ 	-rm -f ./$(DEPDIR)/output.Po
+ 	-rm -f ./$(DEPDIR)/parser.Po
+ 	-rm -f ./$(DEPDIR)/redir.Po
+ 	-rm -f ./$(DEPDIR)/show.Po
+	-rm -f ./$(DEPDIR)/signames.Po
+	-rm -f ./$(DEPDIR)/syntax.Po
+ 	-rm -f ./$(DEPDIR)/system.Po
+ 	-rm -f ./$(DEPDIR)/trap.Po
+ 	-rm -f ./$(DEPDIR)/var.Po
 diff -Paur --no-dereference -- dash.upstream/src/miscbltin.c dash/src/miscbltin.c
 --- dash.upstream/src/miscbltin.c
 +++ dash/src/miscbltin.c
@ -151,18 +182,18 @@ diff -Paur --no-dereference -- dash.upstream/src/output.c dash/src/output.c
 diff -Paur --no-dereference -- dash.upstream/src/parser.c dash/src/parser.c
 --- dash.upstream/src/parser.c
 +++ dash/src/parser.c
-@@ -32,10 +32,6 @@
+@@ -32,10 +32,7 @@
  * SUCH DAMAGE.
  */
 
 -#if HAVE_ALLOCA_H
-#include <alloca.h>
+ #include <alloca.h>
 -#endif
 -
 #include <stdlib.h>
 
 #include "shell.h"
-@@ -1090,10 +1086,12 @@
+@@ -1137,10 +1134,12 @@
 				if (len) {
 					char *str;
 
@ -176,7 +207,7 @@ diff -Paur --no-dereference -- dash.upstream/src/parser.c dash/src/parser.c
 				}
 			}
 		}
-@@ -1300,7 +1298,7 @@
+@@ -1373,7 +1372,7 @@
 	str = NULL;
 	savelen = out - (char *)stackblock();
 	if (savelen > 0) {
@ -185,7 +216,7 @@ diff -Paur --no-dereference -- dash.upstream/src/parser.c dash/src/parser.c
 		memcpy(str, stackblock(), savelen);
 	}
         if (oldstyle) {
-@@ -1400,6 +1398,7 @@
+@@ -1463,6 +1462,7 @@
 	if (str) {
 		memcpy(out, str, savelen);
 		STADJUST(savelen, out);
--- a/ports/dash/dash.port
+++ b/ports/dash/dash.port
@ -1,10 +1,12 @@
 NAME=dash
 BUILD_LIBRARIES=
-VERSION=0.5.7
+VERSION=0.5.11.5
 DISTNAME=$NAME-$VERSION
 COMPRESSION=tar.gz
 ARCHIVE=$DISTNAME.$COMPRESSION
-SHA256SUM=ae89fa9f1145b7748cf0740e1df04cd52fdf8a285da4911dd0f04983efba4e39
+SHA256SUM=db778110891f7937985f29bf23410fe1c5d669502760f584e54e0e7b29e123bd
 UPSTREAM_SITE='http://gondor.apana.org.au/~herbert/dash/files'
 UPSTREAM_ARCHIVE=$ARCHIVE
+LICENSE=BSD-3-Clause
 BUILD_SYSTEM=configure
+MAKE_VARS='V=1'
--- a/ports/libssl/libssl.patch
+++ b/ports/libssl/libssl.patch
@ -26,7 +26,7 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 			unix_dg_tmp_socket = unix_dg_tmp_socket_buf;
 		}
 	}
-@@ -1405,7 +1412,8 @@
+@@ -1403,7 +1410,8 @@
 	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
 	memset(&iov, 0, sizeof(iov));
 
@ -36,7 +36,7 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 	mh.msg_controllen = sizeof(cmsgbuf.buf);
 	cmsg = CMSG_FIRSTHDR(&mh);
 	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
-@@ -1442,6 +1450,7 @@
+@@ -1440,6 +1448,7 @@
 void
 atelnet(int nfd, unsigned char *buf, unsigned int size)
 {
@ -44,7 +44,7 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 	unsigned char *p, *end;
 	unsigned char obuf[4];
 
-@@ -1467,6 +1476,9 @@
+@@ -1465,6 +1474,9 @@
 		if (atomicio(vwrite, nfd, obuf, 3) != 3)
 			warn("Write Error!");
 	}
@ -53,8 +53,8 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 +#endif
 }
 
- 
-@@ -1581,16 +1593,20 @@
+ int
+@@ -1578,16 +1590,20 @@
 			err(1, NULL);
 	}
 	if (Tflag != -1) {
@ -77,7 +77,7 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 			errno = ENOPROTOOPT;
 			err(1, "set IPv6 traffic class not supported");
 		}
-@@ -1608,13 +1624,16 @@
+@@ -1605,13 +1621,16 @@
 	}
 
 	if (ttl != -1) {
@ -96,7 +96,7 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 	}
 
 	if (minttl != -1) {
-@@ -1652,7 +1671,9 @@
+@@ -1649,7 +1668,9 @@
 		{ "af41",		IPTOS_DSCP_AF41 },
 		{ "af42",		IPTOS_DSCP_AF42 },
 		{ "af43",		IPTOS_DSCP_AF43 },
@ -106,7 +106,7 @@ diff -Paur --no-dereference -- libssl.upstream/apps/nc/netcat.c libssl/apps/nc/n
 		{ "cs0",		IPTOS_DSCP_CS0 },
 		{ "cs1",		IPTOS_DSCP_CS1 },
 		{ "cs2",		IPTOS_DSCP_CS2 },
-@@ -1662,11 +1683,21 @@
+@@ -1659,11 +1680,21 @@
 		{ "cs6",		IPTOS_DSCP_CS6 },
 		{ "cs7",		IPTOS_DSCP_CS7 },
 		{ "ef",			IPTOS_DSCP_EF },
--- a/ports/libssl/libssl.port
+++ b/ports/libssl/libssl.port
@ -1,10 +1,10 @@
 NAME=libssl
 BUILD_LIBRARIES=
-VERSION=3.5.3
+VERSION=3.6.1
 DISTNAME=libressl-$VERSION
 COMPRESSION=tar.gz
 ARCHIVE=$DISTNAME.$COMPRESSION
-SHA256SUM=3ab5e5eaef69ce20c6b170ee64d785b42235f48f2e62b095fca5d7b6672b8b28
+SHA256SUM=acfac61316e93b919c28d62d53037ca734de85c46b4d703f19fd8395cf006774
 UPSTREAM_SITE=https://ftp.openbsd.org/pub/OpenBSD/LibreSSL
 UPSTREAM_ARCHIVE=$ARCHIVE
 LICENSE=OpenSSL
--- a/sh/Makefile
+++ b/sh/Makefile
@ -25,6 +25,13 @@ all: $(BINARIES)
 install: all
 	mkdir -p $(DESTDIR)$(BINDIR)
 	install $(BINARIES) $(DESTDIR)$(BINDIR)
+	mkdir -p $(DESTDIR)$(MANDIR)/man1
+	cp sh.1 $(DESTDIR)$(MANDIR)/man1/sh.1
+	ln -sf sh.1 $(DESTDIR)$(MANDIR)/man1/sortix-sh.1
+	mkdir -p $(DESTDIR)$(MANDIR)/man5
+	cp profile.5 $(DESTDIR)$(MANDIR)/man5/profile.5
+	cp proper-sh.5 $(DESTDIR)$(MANDIR)/man5/proper-sh.5
+	cp shrc.5 $(DESTDIR)$(MANDIR)/man5/shrc.5

 sortix-sh: $(SORTIX_SH_SRCS) *.h
 	$(CC) -std=gnu11 $(CFLAGS) $(CPPFLAGS) $(SORTIX_SH_SRCS) -o $@
--- a/sh/editline.c
+++ b/sh/editline.c
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, 2013, 2014, 2015, 2016 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011-2016, 2022 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
@ -18,6 +18,9 @@
 */

 #include <assert.h>
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@ -495,6 +498,161 @@ void edit_line_type_complete(struct edit_line* edit_state)
 	free(partial);
 }

+static size_t get_histsize(void)
+{
+	const char* histfile = getenv("HISTSIZE");
+	if ( histfile && isdigit(*histfile) )
+	{
+		errno = 0;
+		char* end;
+		size_t value = strtoul(histfile, &end, 10);
+		// Enforce a reasonable upper limit to avoid OOM on misconfigurations,
+		// when users try to have unlimited history size, but the below saving
+		// will allocate an array of this size.
+		if ( 1048576 <= value )
+			value = 1048576;
+		if ( !errno && !*end )
+			return value;
+	}
+	return 500;
+}
+
+bool edit_line_history_load(struct edit_line* edit_state, const char* path)
+{
+	if ( !path )
+		return true;
+	FILE* fp = fopen(path, "r");
+	if ( !fp )
+	{
+		if ( errno == ENOENT )
+			return true;
+		warn("%s", path);
+		return false;
+	}
+	char* line = NULL;
+	size_t line_size;
+	ssize_t line_length;
+	while ( 0 < (line_length = getline(&line, &line_size, fp)) )
+	{
+		if ( line[line_length - 1] == '\n' )
+			line[--line_length] = '\0';
+		edit_line_append_history(edit_state, line);
+	}
+	edit_state->history_begun = edit_state->history_used;
+	if ( ferror(fp) )
+		warn("read: %s", path);
+	free(line);
+	fclose(fp);
+	return true;
+}
+
+bool edit_line_history_save(struct edit_line* edit_state, const char* path)
+{
+	size_t histsize = get_histsize();
+	if ( !path || !histsize )
+		return true;
+	// Avoid replacing the null device if used to disable the history.
+	if ( !strcmp(path, "/dev/null") )
+		return true;
+	// TODO: File locking is a better alternative to replacing the actual file.
+	//       A temporary file rename is used to atomically replace the contents
+	//       but may lose the race with other processes.
+	char* tmp;
+	if ( asprintf(&tmp, "%s.XXXXXXXXX", path) < 0 )
+	{
+		warn("malloc");
+		return false;
+	}
+	int fd = mkstemp(tmp);
+	if ( fd < 0 )
+	{
+		if ( errno == EROFS )
+			return true;
+		warn("%s", path);
+		return false;
+	}
+	FILE* fpout = fdopen(fd, "w");
+	if ( !fpout )
+	{
+		warn("%s", path);
+		close(fd);
+		unlink(tmp);
+		free(tmp);
+		return false;
+	}
+	// Merge with any updated history.
+	bool success = true;
+	char** history = calloc(sizeof(char*), histsize);
+	if ( !history )
+		warn("malloc"), success = false;
+	size_t first = 0;
+	size_t used = 0;
+	FILE* fpin;
+	if ( success && (fpin = fopen(path, "r")) )
+	{
+		char* line = NULL;
+		size_t line_size;
+		ssize_t line_length;
+		while ( 0 < (line_length = getline(&line, &line_size, fpin)) )
+		{
+			if ( line[line_length - 1] == '\n' )
+				line[--line_length] = '\0';
+			size_t n = (first + used) % histsize;
+			if ( history[n] )
+				free(history[n]);
+			history[n] = line;
+			if ( used == histsize )
+				first = (first + 1) % histsize;
+			else
+				used++;
+			line = NULL;
+		}
+		if ( ferror(fpin) )
+			warn("read: %s", path), success = false;
+		fclose(fpin);
+	}
+	else if ( errno != ENOENT )
+		warn("%s", path);
+	for ( size_t i = edit_state->history_begun;
+	      success && i < edit_state->history_used;
+	      i++ )
+	{
+		char* line = strdup(edit_state->history[i]);
+		if ( !line )
+		{
+			warn("malloc");
+			success = false;
+			break;
+		}
+		size_t n = (first + used) % histsize;
+		if ( history[n] )
+			free(history[n]);
+		history[n] = line;
+		if ( used == histsize )
+			first = (first + 1) % histsize;
+		else
+			used++;
+		line = NULL;
+	}
+	for ( size_t i = 0; i < used; i++ )
+	{
+		size_t n = (first + i) % histsize;
+		char* line = history[n];
+		if ( success && fprintf(fpout, "%s\n", line) < 0 )
+			warn("%s", tmp), success = false;
+		free(line);
+	}
+	int ret = fclose(fpout);
+	if ( success && ret == EOF )
+		warn("%s", path), success = false;
+	if ( success && rename(tmp, path) < 0 )
+		warn("rename: %s -> %s", tmp, path), success = false;
+	if ( !success )
+		unlink(tmp);
+	free(tmp);
+	return success;
+}
+
 #define SORTIX_LFLAGS (ISORTIX_KBKEY | ISORTIX_CHARS_DISABLE | ISORTIX_32BIT | \
                       ISORTIX_NONBLOCK | ISORTIX_TERMMODE)

--- a/sh/editline.h
+++ b/sh/editline.h
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, 2013, 2014, 2015, 2016 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011-2016, 2022 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
@ -38,6 +38,7 @@ struct edit_line
 	size_t history_used;
 	size_t history_length;
 	size_t history_target;
+	size_t history_begun;
 	void* check_input_incomplete_context;
 	bool (*check_input_incomplete)(void*, const char*);
 	void* trap_eof_opportunity_context;
@ -81,6 +82,8 @@ void edit_line_type_clear(struct edit_line* edit_state);
 void edit_line_type_delete_word_before(struct edit_line* edit_state);
 int edit_line_completion_sort(const void* a_ptr, const void* b_ptr);
 void edit_line_type_complete(struct edit_line* edit_state);
+bool edit_line_history_load(struct edit_line* edit_state, const char* path);
+bool edit_line_history_save(struct edit_line* edit_state, const char* path);
 void edit_line(struct edit_line* edit_state);

 #endif
--- a/sh/profile.5
+++ b/sh/profile.5
@ -0,0 +1,59 @@
+.Dd November 9, 2022
+.Dt PROFILE 5
+.Os
+.Sh NAME
+.Nm profile
+.Nd login shell startup
+.Sh SYNOPSIS
+.Nm ~/.profile
+.Nm /etc/profile
+.Nm /etc/default/profile
+.Sh DESCRIPTION
+Interactive login shell sessions in
+.Xr sh 1
+execute the commands in the
+.Nm
+script upon startup, searching for the user's script at
+.Pa ~/.profile ,
+any system administrator provided script at
+.Pa /etc/profile ,
+or any operating system provided script at
+.Pa /etc/default/profile ,
+whichever exists first.
+.Pp
+The
+.Xr shrc 5
+script is run instead in interactive non-login shell sessions.
+.Sh FILES
+.Bl -tag -width "/etc/default/profile" -compact
+.It Pa ~/.profile
+The user's
+.Nm
+script.
+.It Pa /etc/profile
+The system administor provided
+.Nm
+script.
+.It Pa /etc/default/profile
+The operating system provided
+.Nm
+script.
+.El
+.Sh EXAMPLES
+To portably run the
+.Xr shrc 5
+script upon startup of non-login interactive shells in all shells:
+.Bd -literal -offset indent
+export ENV="$HOME/.shrc"
+.Ed
+.Sh SEE ALSO
+.Xr dash 1 ,
+.Xr sh 1 ,
+.Xr shrc 5
+.Sh BUGS
+.Xr sh 1
+is currently primitive and cannot execute most scripts.
+Beware of sharing the
+.Nm
+script between it and other shells such as
+.Xr dash 1 .
--- a/sh/proper-sh.5
+++ b/sh/proper-sh.5
@ -0,0 +1,49 @@
+.Dd November 16, 2022
+.Dt PROPER-SH 5
+.Os
+.Sh NAME
+.Nm proper-sh
+.Nd name of a better non-interactive shell
+.Sh SYNOPSIS
+.Nm /etc/proper-sh
+.Sh DESCRIPTION
+The
+.Xr sh 1
+program is a thin wrapper that invokes
+.Xr sortix-sh 1
+on interactive use, but this shell is primitive and cannot execute most scripts,
+so non-interactive uses of
+.Xr sh 1
+instead searches for the name of a better shell to execute in this order:
+.Pp
+.Bl -bullet -compact
+.It
+The shell named in the
+.Ev SORTIX_SH_BACKEND
+environment variable.
+.It
+The shell named in the
+.Pa /etc/proper-sh
+file.
+.It
+.Xr dash 1 ,
+if installed.
+.It
+.Sy sortix-sh ,
+if no better shell was found.
+.El
+.Sh ENVIRONMENT
+.Bl -tag -width "SORTIX_SH_BACKEND"
+.It Ev SORTIX_SH_BACKEND
+The name of a better non-interactive shell, taking precedence if set over the
+.Pa /etc/proper-sh
+file.
+.El
+.Sh FILES
+.Bl -tag -width "/etc/proper-sh" -compact
+.It Pa /etc/proper-sh
+File containing the name of a better non-interactive shell.
+.El
+.Sh SEE ALSO
+.Xr dash 1 ,
+.Xr sh 1
--- a/sh/proper-sh.c
+++ b/sh/proper-sh.c
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2014, 2022 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
@ -17,114 +17,85 @@
 * Forward execution to the best shell.
 */

-#include <sys/wait.h>
-
-#include <dirent.h>
-#include <fcntl.h>
+#include <err.h>
+#include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

-const char* getenv_safe(const char* name, const char* def)
+static bool is_supported(int argc, char* argv[])
 {
-	const char* ret = getenv(name);
-	return ret ? ret : def;
-}
-
-bool is_existing_shell(const char* candidate)
-{
-	pid_t child_pid = fork();
-	if ( child_pid < 0 )
-		return false;
-	if ( !child_pid )
+	int i;
+	for ( i = 1; i < argc; i++ )
 	{
-		close(0);
-		close(1);
-		close(2);
-		open("/dev/null", O_RDONLY);
-		open("/dev/null", O_WRONLY);
-		open("/dev/null", O_WRONLY);
-		execlp("which", "which", "--", candidate, (const char*) NULL);
-		exit(127);
-	}
-	int status;
-	waitpid(child_pid, &status, 0);
-	return WIFEXITED(status) && WEXITSTATUS(status) == 0;
-}
-
-char* search_for_proper_shell(void)
-{
-	if ( getenv("SORTIX_SH_BACKEND") )
-	{
-		if ( !getenv("SORTIX_SH_BACKEND")[0] )
-			return NULL;
-		if ( is_existing_shell(getenv("SORTIX_SH_BACKEND")) )
-			return strdup(getenv("SORTIX_SH_BACKEND"));
-	}
-
-	const char* backends_dir_path =
-		getenv_safe("SORTIX_SH_BACKENDS_DIR", "/etc/proper-shells");
-
-	struct dirent** shell_entries;
-	int num_shell_entries = scandir(backends_dir_path, &shell_entries, NULL, alphasort);
-	if ( 0 <= num_shell_entries )
-	{
-		char* result = NULL;
-		for ( int i = 0; i < num_shell_entries; i++ )
-		{
-			struct dirent* entry = shell_entries[i];
-			const char* name = entry->d_name;
-			if ( !strcmp(name, ".") || !strcmp(name, "..") )
-				continue;
-			size_t path_length = strlen(backends_dir_path) + 1 + strlen(name);
-			char* path = (char*) malloc(path_length + 1);
-			if ( !path )
-				continue;
-			stpcpy(stpcpy(stpcpy(path, backends_dir_path), "/"), name);
-			FILE* fp = fopen(path, "r");
-			free(path);
-			if ( !fp )
-				continue;
-			size_t result_size = 0;
-			ssize_t result_length = getline(&result, &result_size, fp);
-			fclose(fp);
-			if ( result_length < 0 )
-			{
-				free(result);
-				continue;
-			}
-			if ( result[result_length-1] == '\n' )
-				result[--result_length] = '\0';
-			if ( !is_existing_shell(result) )
-			{
-				free(result);
-				result = NULL;
-				continue;
-			}
+		const char* arg = argv[i];
+		if ( (arg[0] != '-' && arg[0] != '+') || !arg[1] )
+			break;  // Intentionally not continue and note '+' support.
+		if ( !strcmp(arg, "--") )
 			break;
+		if ( arg[0] == '+' || arg[1] != '-' )
+		{
+			char c;
+			while ( (c = *++arg) ) switch ( c )
+			{
+			case 'e': break;
+			case 'i': break;
+			case 'l': break;
+			case 's': break;
+			default: return false;
+			}
 		}
-		for ( int i = 0; i < num_shell_entries; i++ )
-			free(shell_entries[i]);
-		free(shell_entries);
-		if ( result )
-			return result;
+		else if ( !strcmp(arg, "--help") )
+			;
+		else if ( !strcmp(arg, "--version") )
+			;
+		else
+			return false;
 	}
-
-	return NULL;
+	return i == argc;
 }

 int main(int argc, char* argv[])
 {
-	if ( argc == 1 && isatty(0) && isatty(1) )
-		execvp("sortix-sh", argv);
+	if ( !isatty(0) || !isatty(1) || !is_supported(argc, argv) )
+	{
+		const char* env = getenv("SORTIX_SH_BACKEND");
+		if ( env && env[0] )
+		{
+			execvp(env, argv);
+			if ( errno != ENOENT )
+				err(127, "%s", env);
+		}

-	char* proper_shell = search_for_proper_shell();
-	if ( proper_shell )
-		execvp(proper_shell, argv);
-	free(proper_shell);
+		FILE* fp = fopen("/etc/proper-sh", "r");
+		if ( !fp && errno != ENOENT )
+			err(127, "/etc/proper-sh");
+		if ( fp )
+		{
+			char* proper_sh = NULL;
+			size_t proper_sh_size = 0;
+			ssize_t proper_sh_length = getline(&proper_sh, &proper_sh_size, fp);
+			if ( proper_sh_length < 0 )
+				err(127, "/etc/proper-sh");
+			if ( proper_sh_length && proper_sh[proper_sh_length - 1] == '\n' )
+				proper_sh[--proper_sh_length] = '\0';
+			if ( proper_sh[0] )
+			{
+				execvp(proper_sh, argv);
+				if ( errno != ENOENT )
+					err(127, "%s", proper_sh);
+			}
+			free(proper_sh);
+			fclose(fp);
+		}
+
+		execvp("dash", argv);
+		if ( errno != ENOENT )
+			err(127, "dash");
+	}

 	execvp("sortix-sh", argv);
-	return 127;
+	err(127, "sortix-sh");
 }
--- a/sh/sh.1
+++ b/sh/sh.1
@ -0,0 +1,148 @@
+.Dd November 9, 2022
+.Dt SH 1
+.Os
+.Sh NAME
+.Nm sh
+.Nd shell command interpreter
+.Sh SYNOPSIS
+.Nm sh
+.Op Fl ceils
+.Op Ar script Oo argument ... Oc
+.Nm sortix-sh
+.Op Fl ceils
+.Op Ar script Oo argument ... Oc
+.Sh DESCRIPTION
+.Nm
+is the command line interpreter for the shell language.
+It reads and executes commands from the standard input or the
+.Ar script
+file if specified.
+.Nm
+is interactive if the standard input is a terminal and no
+.Ar script
+file was specified.
+.Pp
+The standard shell
+.Nm sortix-sh
+is currently primitive and cannot execute most scripts.
+.Nm sh
+is currently a thin wrapper that detects non-interactive use and invokes a
+better shell instead, named in the
+.Ev SORTIX_SH_BACKEND
+environment variable if set, or named in
+.Xr proper-sh 5
+if it exists, and otherwise
+.Xr dash 1
+is invoked.
+.Pp
+The options can be unset by prefixing them with a plus
+.Sq +
+instead of a dash
+.Sq - .
+.Pp
+The options are as follows:
+.Bl -tag -width "12345678"
+.It Fl c
+The
+.Ar script
+argument contains the script's text instead of a path to the script file.
+.It Fl e
+Exit if any command exit non-zero.
+.It Fl i
+Interactively read and execute commands.
+.It Fl l
+The shell is a login shell.
+Interactive shells run the
+.Xr profile 5
+script on startup instead of the
+.Xr shrc
+script.
+This option is set if the shell is invoked by a name starting with a dash
+.Sq - .
+.It Fl s
+Read commands from the standard input (the default).
+This option can be combined with the
+.Fl c
+option to execute the script text in the
+.Ar script
+argument before reading normally from the standard input
+.El
+.Sh ENVIRONMENT
+.Nm
+uses environment these variables:
+.Bl -tag -width "HISTFILE"
+.It Ev ENV
+File to execute on non-login interactive startup instead of
+.Pa ~/.shrc
+per
+.Xr shrc 5 .
+This variable is subject to path expansion.
+.It Ev HISTFILE
+Save the shell history in this file.
+The default is
+.Pa ~/.sh_history .
+.It Ev HISTSIZE
+Maximum number of commands in the saved shell history.
+The default is 500.
+.It Ev HOME
+The user's home directory
+.Sq ( ~ ) .
+.It Ev PATH
+The colon-separated list of directory paths to search for programs.
+.It Ev PS1
+Interactive shell prompt when expecting a new command.
+.It Ev PS2
+Interactive shell prompt when the current command continues onto another line.
+.It Ev PWD
+Set to the current working directory.
+.It Ev SHELL
+Set to
+.Nm .
+.It Ev SHLVL
+Depth of recursive shell sessions.
+The outermost interactive shell (depth 1) will currently refuse to exit on an
+end-of-file condition (^D) when on the
+.Pa /dev/tty1
+terminal to avoid accidentally powering off the machine.
+.It Ev SORTIX_SH_BACKEND
+Name of a better shell to use for non-interactive use per
+.Xr proper-sh 5 .
+This variable takes precedence over
+.Pa /etc/proper-sh .
+.El
+.Sh FILES
+.Bl -tag -width "/etc/proper-sh" -compact
+.It Pa ~/.profile , /etc/profile , /etc/default/profile
+.Xr profile 5
+script whose commands are run on non-login interactive shell startup.
+.It Pa /etc/proper-sh
+Name of a better shell to use for non-interactive use per
+.Xr proper-sh 5 .
+The
+.Ev SORTIX_SH_BACKEND
+environment variable takes precedence over this file if set.
+.Xr dash 1
+is used by default if it is installed.
+.It Pa ~/.sh_history
+The saved shell history.
+This location is controlled by the
+.Ev HISTFILE
+environment variable.
+.It Pa ~/.shrc , /etc/shrc , /etc/default/shrc
+.Xr shrc 5
+script whose commands are run on login interactive shell startup.
+The
+.Ev ENV
+environment variable overrides the search for the script if set.
+.El
+.Sh EXIT STATUS
+.Nm
+exits with the same exit status as the last run command, or 0 if no command has
+been run.
+.Sh SEE ALSO
+.Xr dash 1 ,
+.Xr profile 5 ,
+.Xr proper-sh 5 ,
+.Xr session 5 ,
+.Xr shrc 5 ,
+.Xr login 8
--- a/sh/sh.c
+++ b/sh/sh.c
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, 2013, 2014, 2015, 2016 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011-2016, 2022 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
@ -23,6 +23,7 @@
 #include <assert.h>
 #include <ctype.h>
 #include <dirent.h>
+#include <err.h>
 #include <errno.h>
 #include <error.h>
 #include <fcntl.h>
@ -38,6 +39,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <termios.h>
+#include <time.h>
 #include <unistd.h>
 #include <wchar.h>
 #include <wctype.h>
@ -51,17 +53,19 @@
 #include "showline.h"
 #include "util.h"

-const char* builtin_commands[] =
+static const char* builtin_commands[] =
 {
 	"cd",
 	"exit",
 	"unset",
 	"clearenv",
+	"history",
 	(const char*) NULL,
 };

-int status = 0;
-bool foreground_shell;
+static bool foreground_shell;
+static int status = 0;
+static struct edit_line edit_state;

 static bool is_proper_absolute_path(const char* path)
 {
@ -1295,7 +1299,7 @@ struct execute_result execute(char** tokens,
 		//       foreground process group, but bar dies prior to foo's tcsetpgrp
 		//       call, because then the shell would run tcsetpgrp to take back
 		//       control, and only then would foo do its tcsetpgrp call.
-		while ( foreground_shell && pgid == -1 && tcgetpgrp(0) != childpid )
+		while ( interactive && pgid == -1 && tcgetpgrp(0) != childpid )
 			sched_yield();

 		struct execute_result result;
@ -1306,7 +1310,7 @@ struct execute_result execute(char** tokens,
 	}

 	setpgid(0, pgid != -1 ? pgid : 0);
-	if ( foreground_shell && pgid == -1 )
+	if ( interactive && pgid == -1 )
 	{
 		sigset_t oldset, sigttou;
 		sigemptyset(&sigttou);
@ -1339,6 +1343,19 @@ struct execute_result execute(char** tokens,
 		}
 	}

+	if ( strcmp(argv[0], "history") == 0 )
+	{
+		for ( size_t i = 0; i < edit_state.history_used; i++ )
+		{
+			const char* line = edit_state.history[i];
+			if ( fprintf(stdout, "%5zu  %s\n", i + 1, line) < 0 )
+				err(1, "stdout");
+		}
+		if ( fflush(stdout) == EOF )
+			err(1, "stdout");
+		exit(0);
+	}
+
 	execvp(argv[0], argv);

 	if ( interactive && errno == ENOENT )
@ -1491,12 +1508,15 @@ readcmd:
 		//       as that may have side effects if a process checks for this
 		//       behavior and then unexpectedly the shell takes back support
 		//       without the usual ^Z mechanism.
-		sigset_t oldset, sigttou;
-		sigemptyset(&sigttou);
-		sigaddset(&sigttou, SIGTTOU);
-		sigprocmask(SIG_BLOCK, &sigttou, &oldset);
-		tcsetpgrp(0, getpgid(0));
-		sigprocmask(SIG_SETMASK, &oldset, NULL);
+		if ( interactive )
+		{
+			sigset_t oldset, sigttou;
+			sigemptyset(&sigttou);
+			sigaddset(&sigttou, SIGTTOU);
+			sigprocmask(SIG_BLOCK, &sigttou, &oldset);
+			tcsetpgrp(0, getpgid(0));
+			sigprocmask(SIG_SETMASK, &oldset, NULL);
+		}
 		pgid = -1;
 		status = 0;
 		goto readcmd;
@ -1520,12 +1540,15 @@ readcmd:
 			status = 1;
 			return status;
 		}
-		sigset_t oldset, sigttou;
-		sigemptyset(&sigttou);
-		sigaddset(&sigttou, SIGTTOU);
-		sigprocmask(SIG_BLOCK, &sigttou, &oldset);
-		tcsetpgrp(0, getpgid(0));
-		sigprocmask(SIG_SETMASK, &oldset, NULL);
+		if ( interactive )
+		{
+			sigset_t oldset, sigttou;
+			sigemptyset(&sigttou);
+			sigaddset(&sigttou, SIGTTOU);
+			sigprocmask(SIG_BLOCK, &sigttou, &oldset);
+			tcsetpgrp(0, getpgid(0));
+			sigprocmask(SIG_SETMASK, &oldset, NULL);
+		}
 		if ( WIFSIGNALED(exitstatus) && WTERMSIG(exitstatus) == SIGINT )
 			printf("^C\n");
 		else if ( WIFSIGNALED(exitstatus) && WTERMSIG(exitstatus) != SIGPIPE )
@ -1834,6 +1857,152 @@ size_t do_complete(char*** completions_ptr,
 	return *completions_ptr = completions, completions_count;
 }

+static void eval_ps_append_c(struct stringbuf* buf, char c)
+{
+	if ( c == '\\' || c == '\'' || c == '"' || c == '$' || c == '`' )
+		stringbuf_append_c(buf, '\\');
+	stringbuf_append_c(buf, c);
+}
+
+static void eval_ps_append(struct stringbuf* buf, const char* str)
+{
+	for ( size_t i = 0; str[i]; i++ )
+		eval_ps_append_c(buf, str[i]);
+}
+
+static char* eval_ps(const char* ps)
+{
+	struct stringbuf buf;
+	stringbuf_begin(&buf);
+	bool escaped = false;
+	while ( *ps )
+	{
+		char c = *ps++;
+		if ( !escaped && c == '\\' )
+		{
+			escaped = true;
+			continue;
+		}
+		else if ( escaped && '0' <= c && c <= '7' )
+		{
+			unsigned char byte = c - '0';
+			if ( '0' <= *ps && *ps <= '7' )
+			{
+				byte = byte * 8 + *ps++ - '0';
+				if ( byte <= 037 && '0' <= *ps && *ps <= '7' )
+					byte = byte * 8 + *ps++ - '0';
+			}
+			eval_ps_append_c(&buf, byte);
+		}
+		else if ( escaped && c == 'a' )
+			eval_ps_append_c(&buf, '\a');
+		else if ( escaped && c == 'e' )
+			eval_ps_append_c(&buf, '\e');
+		else if ( escaped && (c == 'h' || c == 'H') )
+		{
+			char hostname[HOST_NAME_MAX + 1] = "?";
+			gethostname(hostname, sizeof(hostname));
+			if ( c == 'h' )
+				hostname[strcspn(hostname, ".")] = '\0';
+			eval_ps_append(&buf, hostname);
+		}
+		else if ( escaped && c == 'l' )
+		{
+			char* tty = ttyname(0);
+			if ( tty )
+				eval_ps_append(&buf, basename(tty));
+			else
+				eval_ps_append_c(&buf, '?');
+		}
+		else if ( escaped && c == 'n' )
+			eval_ps_append_c(&buf, '\n');
+		else if ( escaped && c == 'r' )
+			eval_ps_append_c(&buf, '\r');
+		else if ( escaped && c == 's' )
+		{
+			const char* argv0 = getenv("0");
+			if ( !argv0 )
+				argv0 = program_invocation_short_name;
+			char* base = strdup(argv0);
+			if ( !base )
+				eval_ps_append_c(&buf, '?');
+			else
+			{
+				eval_ps_append(&buf, basename(base));
+				free(base);
+			}
+		}
+		else if ( escaped && (c == 't' || c == 'T' || c == '@' || c == 'A') )
+		{
+			const char* format = "";
+			switch ( c )
+			{
+			case 't': format = "%H:%M:%S"; break;
+			case 'T': format = "%I:%M:%S"; break;
+			case '@': format = "%I:%M %p"; break;
+			case 'A': format = "%H:%M"; break;
+			}
+			time_t now = time(NULL);
+			struct tm tm;
+			localtime_r(&now, &tm);
+			char buffer[16] = "";
+			strftime(buffer, sizeof(buffer), format, &tm);
+			eval_ps_append(&buf, buffer);
+		}
+		else if ( escaped && c == 'u' )
+		{
+			char* user = getlogin();
+			eval_ps_append(&buf, user ? user : "?");
+		}
+		else if ( escaped && (c == 'w' || c == 'W') )
+		{
+			char* dir = get_current_dir_name();
+			const char* home = getenv("HOME");
+			if ( !dir )
+				eval_ps_append_c(&buf, '?');
+			else if ( c == 'w' )
+			{
+				size_t home_len = home ? strlen(home) : 0;
+				if ( home_len && !strncmp(dir, home, home_len) )
+				{
+					eval_ps_append_c(&buf, '~');
+					eval_ps_append(&buf, dir + home_len);
+				}
+				else
+					eval_ps_append(&buf, dir);
+			}
+			else if ( home && !strcmp(dir, home) )
+				eval_ps_append_c(&buf, '~');
+			else
+				eval_ps_append(&buf, basename(dir));
+			free(dir);
+		}
+		else if ( escaped && c == '$' )
+			eval_ps_append_c(&buf, getuid() == 0 ? '#' : '$');
+		else if ( escaped && (c == '[' || c == ']') )
+		{
+			// TODO: Ignoring this sequence when predicting cursor position.
+		}
+		else
+		{
+			if ( escaped || c == '\'' || c == '"' )
+				stringbuf_append_c(&buf, '\\');
+			stringbuf_append_c(&buf, c);
+		}
+		escaped = false;
+	}
+	char* string = stringbuf_finish(&buf);
+	if ( !string )
+		return NULL;
+	char* expanded = token_expand_variables(string);
+	free(string);
+	if ( !expanded )
+		return NULL;
+	char* finalized = token_finalize(expanded);
+	free(expanded);
+	return finalized;
+}
+
 struct sh_read_command
 {
 	char* command;
@ -1846,7 +2015,6 @@ void read_command_interactive(struct sh_read_command* sh_read_command)
 {
 	update_env();

-	static struct edit_line edit_state; // static to preserve command history.
 	edit_state.in_fd = 0;
 	edit_state.out_fd = 1;
 	edit_state.check_input_incomplete_context = NULL;
@ -1856,45 +2024,15 @@ void read_command_interactive(struct sh_read_command* sh_read_command)
 	edit_state.complete_context = NULL;
 	edit_state.complete = do_complete;

-	char* current_dir = get_current_dir_name();
-
-	const char* print_username = getlogin();
-	if ( !print_username )
-		print_username = getuid() == 0 ? "root" : "?";
-	char hostname[HOST_NAME_MAX + 1];
-	if ( gethostname(hostname, sizeof(hostname)) < 0 )
-		strlcpy(hostname, "(none)", sizeof(hostname));
-	const char* print_hostname = hostname;
-	const char* print_dir = current_dir ? current_dir : "?";
-	const char* home_dir = getenv_safe("HOME");
-
-	const char* print_dir_1 = print_dir;
-	const char* print_dir_2 = "";
-	char prompt_char = getuid() == 0 ? '#' : '$';
-
-	size_t home_dir_len = strlen(home_dir);
-	if ( home_dir_len && strncmp(print_dir, home_dir, home_dir_len) == 0 )
-	{
-		print_dir_1 = "~";
-		print_dir_2 = print_dir + home_dir_len;
-	}
-
-	char* ps1;
-	asprintf(&ps1, "\e[;1;32m%s@%s \e[1;34m%s%s %c\e[m ",
-		print_username,
-		print_hostname,
-		print_dir_1,
-		print_dir_2,
-		prompt_char);
-
-	free(current_dir);
-
-	edit_state.ps1 = ps1;
-	edit_state.ps2 = "> ";
+	const char* def_ps1 = "\\033[;1;32m\\u@\\H \\033[1;34m\\w \\$\\033[m ";
+	const char* def_ps2 = "> ";
+	edit_state.ps1 = eval_ps(getenv_safe_def("PS1", def_ps1));
+	edit_state.ps2 = eval_ps(getenv_safe_def("PS2", def_ps2));

 	edit_line(&edit_state);

-	free(ps1);
+	free((char*) edit_state.ps1);
+	free((char*) edit_state.ps2);

 	if ( edit_state.abort_editing )
 	{
@ -2004,12 +2142,12 @@ void read_command_non_interactive(struct sh_read_command* sh_read_command,
 	sh_read_command->command = command;
 }

-int run(FILE* fp,
-        const char* fp_name,
-        bool interactive,
-        bool exit_on_error,
-        bool* script_exited,
-        int status)
+static int run(FILE* fp,
+               const char* fp_name,
+               bool interactive,
+               bool exit_on_error,
+               bool* script_exited,
+               int status)
 {
 	// TODO: The interactive read code should cope when the input is not a
 	//       terminal; it should print the prompt and then read normally without
@ -2058,6 +2196,83 @@ int run(FILE* fp,
 	return status;
 }

+static char* find_rc(bool login)
+{
+	const char* env = getenv("ENV");
+	if ( !login && env )
+	{
+		// TODO: Path expansion.
+		char* result = strdup(env);
+		if ( !result )
+			err(1, "malloc");
+		return result;
+	}
+	const char* home = getenv("HOME");
+	const char* rcname = login ? "profile" : "shrc";
+	const char* dirs[] = { home, "/etc", "/etc/default" };
+	bool found = false;
+	for ( size_t i = 0; !found && i < sizeof(dirs) / sizeof(dirs[0]); i++ )
+	{
+		char* rc;
+		if ( asprintf(&rc, "%s%s%s", dirs[i], i ? "/" : "/.", rcname) < 0 )
+			err(1, "malloc");
+		if ( (found = !access(rc, F_OK)) )
+			return rc;
+	}
+	return NULL;
+}
+
+static int top(FILE* fp,
+               const char* fp_name,
+               bool interactive,
+               bool exit_on_error,
+               bool login,
+               bool* script_exited,
+               int status)
+{
+	if ( interactive )
+	{
+		const char* home = getenv("HOME");
+		const char* histfile = getenv("HISTFILE");
+		if ( !histfile && home )
+		{
+			char* path;
+			if ( asprintf(&path, "%s/.sh_history", home) < 0 ||
+			     setenv("HISTFILE", path, 1) < 0 )
+				err(1, "malloc");
+			free(path);
+		}
+
+		char* rc = find_rc(login);
+		if ( rc )
+		{
+			FILE* rcfp = fopen(rc, "r");
+			if ( !rcfp )
+				warn("%s", rc);
+			else
+			{
+				status = run(rcfp, rc, false, exit_on_error, script_exited,
+				             status);
+				fclose(rcfp);
+			}
+			free(rc);
+		}
+
+		if ( *script_exited || (status != 0 && exit_on_error) )
+			return status;
+
+		edit_line_history_load(&edit_state, getenv("HISTFILE"));
+	}
+
+	status = run(fp, fp_name, interactive, exit_on_error, script_exited,
+	             status);
+
+	if ( interactive )
+		edit_line_history_save(&edit_state, getenv("HISTFILE"));
+
+	return status;
+}
+
 static void compact_arguments(int* argc, char*** argv)
 {
 	for ( int i = 0; i < *argc; i++ )
@ -2133,8 +2348,10 @@ int main(int argc, char* argv[])
 	bool flag_c_first_operand_is_command = false;
 	bool flag_e_exit_on_error = false;
 	bool flag_i_interactive = false;
+	bool flag_l_login = argv[0][0] == '-';
 	bool flag_s_stdin = false;

+	// The well implemented options are recognized in proper-sh.c.
 	const char* argv0 = argv[0];
 	for ( int i = 1; i < argc; i++ )
 	{
@ -2149,7 +2366,11 @@ int main(int argc, char* argv[])
 			char c;
 			while ( (c = *++arg) ) switch ( c )
 			{
+			case 'c': flag_c_first_operand_is_command = false; break;
 			case 'e': flag_e_exit_on_error = false; break;
+			case 'i': flag_i_interactive = false; break;
+			case 'l': flag_l_login = false; break;
+			case 's': flag_s_stdin = false; break;
 			default:
 				fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
 				help(stderr, argv0);
@ -2164,6 +2385,7 @@ int main(int argc, char* argv[])
 			case 'c': flag_c_first_operand_is_command = true; break;
 			case 'e': flag_e_exit_on_error = true; break;
 			case 'i': flag_i_interactive = true; break;
+			case 'l': flag_l_login = true; break;
 			case 's': flag_s_stdin = true; break;
 			default:
 				fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
@ -2205,7 +2427,7 @@ int main(int argc, char* argv[])
 	char ppidstr[3 * sizeof(pid_t)];
 	snprintf(pidstr, sizeof(pidstr), "%ji", (intmax_t) getpid());
 	snprintf(ppidstr, sizeof(ppidstr), "%ji", (intmax_t) getppid());
-	setenv("SHELL", argv[0], 1);
+	setenv("SHELL", argv[0] + (argv[0][0] == '-'), 1);
 	setenv("$", pidstr, 1);
 	setenv("PPID", ppidstr, 1);
 	setenv("?", "0", 1);
@ -2234,8 +2456,8 @@ int main(int argc, char* argv[])
 		if ( !fp )
 			error(2, errno, "fmemopen");

-		status = run(fp, "<command-line>", false, flag_e_exit_on_error,
-		             &script_exited, status);
+		status = top(fp, "<command-line>", false, flag_e_exit_on_error,
+		             flag_l_login, &script_exited, status);

 		fclose(fp);

@ -2245,8 +2467,8 @@ int main(int argc, char* argv[])
 		if ( flag_s_stdin )
 		{
 			bool is_interactive = flag_i_interactive || isatty(fileno(stdin));
-			status = run(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
-			             &script_exited, status);
+			status = top(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
+			             flag_l_login, &script_exited, status);
 			if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 				exit(status);
 		}
@ -2261,8 +2483,8 @@ int main(int argc, char* argv[])
 		}

 		bool is_interactive = flag_i_interactive || isatty(fileno(stdin));
-		status = run(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
-		             &script_exited, status);
+		status = top(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
+		             flag_l_login, &script_exited, status);
 		if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 			exit(status);
 	}
@ -2279,8 +2501,8 @@ int main(int argc, char* argv[])
 		FILE* fp = fopen(path, "r");
 		if ( !fp )
 			error(127, errno, "%s", path);
-		status = run(fp, path, false, flag_e_exit_on_error, &script_exited,
-		             status);
+		status = top(fp, path, false, flag_e_exit_on_error, flag_l_login,
+		             &script_exited, status);
 		fclose(fp);
 		if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 			exit(status);
@ -2288,8 +2510,8 @@ int main(int argc, char* argv[])
 	else
 	{
 		bool is_interactive = flag_i_interactive || isatty(fileno(stdin));
-		status = run(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
-		             &script_exited, status);
+		status = top(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
+		             flag_l_login, &script_exited, status);
 		if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 			exit(status);
 	}
--- a/sh/shrc.5
+++ b/sh/shrc.5
@ -0,0 +1,81 @@
+.Dd November 9, 2022
+.Dt SHRC 5
+.Os
+.Sh NAME
+.Nm shrc
+.Nd login shell startup
+.Sh SYNOPSIS
+.Nm $ENV
+.Nm ~/.shrc
+.Nm /etc/shrc
+.Nm /etc/default/shrc
+.Sh DESCRIPTION
+Interactive non-login shell sessions in
+.Xr sh 1
+execute the commands in the
+.Nm
+script upon startup, using the
+.Pa ENV
+environment variable with path expansion if set, and otherwise searching for the
+user's script at
+.Pa ~/.shrc ,
+any system administrator provided script at
+.Pa /etc/shrc ,
+or any operating system provided script at
+.Pa /etc/default/shrc ,
+whichever exists first.
+.Pp
+The
+.Xr profile 5
+script is run instead in interactive login shell sessions.
+.Sh ENVIRONMENT
+.Bl -tag -width "ENV"
+.It Ev ENV
+File to execute on non-login interactive startup instead of searching the
+standard paths for the
+.Nm
+script.
+This variable is subject to path expansion.
+.El
+.Sh FILES
+.Bl -tag -width "/etc/default/shrc" -compact
+.It Pa ~/.shrc
+The user's
+.Nm
+script.
+.It Pa /etc/shrc
+The system administor provided
+.Nm
+script.
+.It Pa /etc/default/shrc
+The operating system provided
+.Nm
+script.
+.El
+.Sh SEE ALSO
+.Xr dash 1 ,
+.Xr sh 1 ,
+.Xr shrc 5
+.Sh CAVEATS
+.Xr dash
+does not use the
+.Nm
+script, but instead only uses the
+.Ev ENV
+environment variable.
+To invoke the
+.Nm
+script portably across all standard shells upon startup of non-interactive login
+sells, set the
+.Ev ENV
+variable to the user's
+.Nm
+script per the example in
+.Xr profile 5 .
+.Sh BUGS
+.Xr sh 1
+is currently primitive and cannot execute most scripts.
+Beware of sharing the
+.Nm
+script between it and other shells such as
+.Xr dash 1 .
--- a/share/init/single-user
+++ b/share/init/single-user
@ -6,4 +6,4 @@ need tty

 cd "$HOME"
 exit-code-meaning poweroff-reboot
-exec "$SHELL"
+exec "$SHELL" -l
Author	SHA1	Message	Date
Jonas 'Sortie' Termansen	2ace33176c	Add sh(1) prompt variable expansion.	2022-11-20 22:15:51 +01:00
Jonas 'Sortie' Termansen	159415c3b1	Implement profile(5) and shrc(5) in sh(1).	2022-11-19 18:01:30 +01:00
Jonas 'Sortie' Termansen	c6af3bc074	Add sh(1) history builtin.	2022-11-19 18:01:30 +01:00
Jonas 'Sortie' Termansen	3c69791078	Save sh(1) history in ~/.sh_history.	2022-11-19 18:01:30 +01:00
Jonas 'Sortie' Termansen	f4152b3863	Document sh(1).	2022-11-16 21:10:46 +01:00
Jonas 'Sortie' Termansen	6bab3819e2	Replace /etc/proper-shells with /etc/proper-sh defaulting to dash.	2022-11-16 21:10:46 +01:00
Juhani Krekelä	212539c9de	Update to dash-0.5.11.5.	2022-11-16 20:29:22 +01:00
Juhani Krekelä	cc9c031e5e	Update to libressl-3.6.1.	2022-11-16 20:23:51 +01:00
Jonas 'Sortie' Termansen	a8c05711aa	Switch bga(4) to the new PCI API.	2022-11-16 20:22:29 +01:00
Jonas 'Sortie' Termansen	aefec2f7cd	Don't warn on read-only /var/log filesystem.	2022-11-16 20:22:29 +01:00
Jonas 'Sortie' Termansen	07dd21146b	Fix sh(1) changing foreground group when non-interactive.	2022-11-16 20:16:34 +01:00