Implement profile(5) and shrc(5) in sh(1).

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) )

sh/Makefile

@@ -29,7 +29,9 @@ install: all
 	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 $@

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 .

sh/proper-sh.c

@@ -42,6 +42,7 @@ static bool is_supported(int argc, char* argv[])
 			{
 			case 'e': break;
 			case 'i': break;
+			case 'l': break;
 			case 's': break;
 			default: return false;
 			}

sh/sh.1

@@ -6,10 +6,10 @@
 .Nd shell command interpreter
 .Sh SYNOPSIS
 .Nm sh
-.Op Fl ceis
+.Op Fl ceils
 .Op Ar script Oo argument ... Oc
 .Nm sortix-sh
-.Op Fl ceis
+.Op Fl ceils
 .Op Ar script Oo argument ... Oc
 .Sh DESCRIPTION
 .Nm
@@ -50,6 +50,15 @@ argument contains the script's text instead of a path to the script file.
 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
@@ -62,6 +71,12 @@ argument before reading normally from the standard input
 .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
@@ -93,6 +108,9 @@ This variable takes precedence over
 .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 .
@@ -106,6 +124,12 @@ 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
@@ -113,6 +137,8 @@ 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

sh/sh.c

@@ -2079,36 +2079,81 @@ static 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;
+		const char* home = getenv("HOME");
 		const char* histfile = getenv("HISTFILE");
-		if ( !histfile && (home = getenv("HOME")) )
+		if ( !histfile && home )
 		{
 			char* path;
 			if ( asprintf(&path, "%s/.sh_history", home) < 0 ||
 			     setenv("HISTFILE", path, 1) < 0 )
 				err(1, "malloc");
 			free(path);
-			histfile = getenv("HISTFILE");
 		}
 
-		edit_line_history_load(&edit_state, histfile);
+		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"));
 	}
 
-	int r = run(fp, fp_name, interactive, exit_on_error, script_exited, status);
+	status = run(fp, fp_name, interactive, exit_on_error, script_exited,
+	             status);
 
 	if ( interactive )
 		edit_line_history_save(&edit_state, getenv("HISTFILE"));
 
-	return r;
+	return status;
 }
 
 static void compact_arguments(int* argc, char*** argv)
@@ -2186,8 +2231,10 @@ 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++ )
 	{
@@ -2205,6 +2252,7 @@ int main(int argc, char* argv[])
 			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);
@@ -2220,6 +2268,7 @@ 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);
@@ -2261,7 +2310,7 @@ 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);
@@ -2291,7 +2340,7 @@ int main(int argc, char* argv[])
 			error(2, errno, "fmemopen");
 
 		status = top(fp, "<command-line>", false, flag_e_exit_on_error,
-		             &script_exited, status);
+		             flag_l_login, &script_exited, status);
 
 		fclose(fp);
 
@@ -2302,7 +2351,7 @@ int main(int argc, char* argv[])
 		{
 			bool is_interactive = flag_i_interactive || isatty(fileno(stdin));
 			status = top(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
-			             &script_exited, status);
+			             flag_l_login, &script_exited, status);
 			if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 				exit(status);
 		}
@@ -2318,7 +2367,7 @@ int main(int argc, char* argv[])
 
 		bool is_interactive = flag_i_interactive || isatty(fileno(stdin));
 		status = top(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
-		             &script_exited, status);
+		             flag_l_login, &script_exited, status);
 		if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 			exit(status);
 	}
@@ -2335,8 +2384,8 @@ int main(int argc, char* argv[])
 		FILE* fp = fopen(path, "r");
 		if ( !fp )
 			error(127, errno, "%s", path);
-		status = top(fp, path, false, flag_e_exit_on_error, &script_exited,
+		status = top(fp, path, false, flag_e_exit_on_error, flag_l_login,
-		             status);
+		             &script_exited, status);
 		fclose(fp);
 		if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 			exit(status);
@@ -2345,7 +2394,7 @@ int main(int argc, char* argv[])
 	{
 		bool is_interactive = flag_i_interactive || isatty(fileno(stdin));
 		status = top(stdin, "<stdin>", is_interactive, flag_e_exit_on_error,
-		             &script_exited, status);
+		             flag_l_login, &script_exited, status);
 		if ( script_exited || (status != 0 && flag_e_exit_on_error) )
 			exit(status);
 	}

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 .

share/init/single-user

@@ -6,4 +6,4 @@ need tty
 
 cd "$HOME"
 exit-code-meaning poweroff-reboot
-exec "$SHELL"
+exec "$SHELL" -l