Wednesday, 2004-08-25, 12:00:05 EST

CHANGES:
	* Fixed an error I had made in substparm() which can cause a
	  stack overflow in main().

	* The error() function was missing a call to lseek(2) for
	  non-interactive shells.  This has been added for general
	  compatibility with the Thompson shell.

	  Please note that this change causes some of the tests run
	  by `make check' to fail.  This is expected; the tests in
	  question need modification to deal with this.  This will
	  be done before the next release of osh.

	* Changed a few more instances of exit(...) to DOEXIT(...).
	  This is a simple macro that calls exit(3) or _exit(2) as
	  needed...  Basically, exit(3) in the parent process or
	  _exit(2) in the child process.

	* Did some general cleaning here and there...

Jeffrey Allen Neitzel
============================================================
--- osh.c.orig	Thu Aug 12 11:27:33 2004
+++ osh.c	Wed Aug 25 12:00:05 2004
@@ -218,7 +218,7 @@
 int	pxpipe(char *, int, int);
 char	*quote(char *, int);
 void	rcfile(int *);
-char	*readline(char *, int, size_t);
+char	*readline(char *, size_t);
 int	*redirect(char **, int *, int);
 void	shell_init(void);
 void	sigmsg(int, pid_t);
@@ -235,13 +235,12 @@
 main(int argc, char **argv)
 {
 	off_t ioff;
-	int ch, rcflag;
-	unsigned char tflag;
+	int ch, onecmd, rcflag;
 	char line[LINELEN];
 	char *bs, *pr;
 
 	shell_init();
-	rcflag = tflag = 0;
+	rcflag = 0;
 
 	/* Setup the positional parameters. */
 	cmdnam = argv[1];
@@ -248,28 +247,22 @@
 	posav = &argv[1];
 	posac = argc - 1;
 
-	/* Determine how the shell was invoked and act accordingly. */
-	if (argc == 1) {
-		if (isatty(STDIN_FILENO) && isatty(STDERR_FILENO)) {
-			if (signal(SIGINT, SIG_IGN) == SIG_DFL)
-				dointr = 1;
-			signal(SIGQUIT, SIG_IGN);
-			signal(SIGTERM, SIG_IGN);
-			if (*argv[0] == '-')
-				rcfile(&rcflag);
-		} else
-			shtype = OTHER;
-	} else if (*argv[1] == '-') { /* non-interactive shell */
-		/*
-		 * This implementation behaves exactly like the Sixth Edition
-		 * Unix shell WRT options.  For compatibility, any option is
-		 * accepted w/o producing an error.
-		 */
+	/*
+	 * This implementation behaves exactly like the Sixth Edition
+	 * Unix shell WRT options.  For compatibility, any option is
+	 * accepted w/o producing an error.
+	 */
+	if (argc > 1 && *argv[1] == '-') {
+
 		shtype = OTHER;
+		pr = NULL;
+		onecmd = 0;
+
 		if (signal(SIGINT, SIG_IGN) == SIG_DFL)
 			dointr = 1;
 		signal(SIGQUIT, SIG_IGN);
 		signal(SIGTERM, SIG_IGN);
+
 		switch (*(argv[1] + 1)) {
 		case 'c':
 			/* osh -c [string]
@@ -278,7 +271,6 @@
 			if (argv[2] == NULL) /* read from input w/o prompting */
 				break;
 
-			/* Resetting posav and posac here is not compatible. */
 			posav += 1;
 			posac -= 1;
 
@@ -285,23 +277,18 @@
 			strncpy(line, argv[2], (size_t)LINELEN);
 			if (line[LINELEN - 1] != '\0')
 				error("Command line overflow");
-
-			/* Deal w/ '\' characters at end of string. */
 			pr = line + strlen(line) - 1;
-			for (bs = pr; bs >= line && *bs == '\\'; --bs)
-				;	/* nothing */
-			if ((pr - bs) % 2 == 1)
-				return(0);
-
-			/* Parse and execute string as a command line. */
-			if (substparm(line) && !pxline(line, PX_SYNEXEC))
-				error("syntax error");
-			return(status);
+			onecmd = 1;
+			break;
 		case 't':
 			/* osh -t
 			 * XXX: `-tanything' works too (compatible).
 			 */
-			tflag = 1;
+			pr = readline(line, (size_t)LINELEN);
+			if (pr == NULL)
+				return(0);
+			pr -= 1;
+			onecmd = 1;
 			break;
 		default:
 			/* XXX (undocumented):
@@ -310,6 +297,30 @@
 			 */
 			break;
 		}
+
+		if (onecmd) {
+			/* Deal w/ '\' characters at end of command line. */
+			for (bs = pr; bs >= line && *bs == '\\'; --bs)
+				;	/* nothing */
+			if ((pr - bs) % 2 == 1)
+				return(0);
+
+			/* Parse and execute command line. */
+			if (substparm(line) && !pxline(line, PX_SYNEXEC))
+				error("syntax error");
+			return(status);
+		}
+
+	} else if (argc == 1) {
+		if (isatty(STDIN_FILENO) && isatty(STDERR_FILENO)) {
+			if (signal(SIGINT, SIG_IGN) == SIG_DFL)
+				dointr = 1;
+			signal(SIGQUIT, SIG_IGN);
+			signal(SIGTERM, SIG_IGN);
+			if (*argv[0] == '-')
+				rcfile(&rcflag);
+		} else
+			shtype = OTHER;
 	} else {
 		/* osh file [arg1 ...] */
 		shtype = COMMANDFILE;
@@ -336,7 +347,7 @@
 		if (INTERACTIVE)
 			write(STDERR_FILENO, si.uid ? "% " : "# ", (size_t)2);
 
-		pr = readline(line, STDIN_FILENO, (size_t)LINELEN);
+		pr = readline(line, (size_t)LINELEN);
 		if (pr == NULL)
 			break;
 		if (pr == (char *)-1)
@@ -351,11 +362,8 @@
 				;	/* nothing */
 			if ((pr - bs - 1) % 2 == 0)
 				break;
-			if (tflag)
-				return(0);
 			*(pr - 1) = ' ';
-			pr = readline(pr, STDIN_FILENO,
-				(size_t)LINELEN - (pr - line));
+			pr = readline(pr, (size_t)LINELEN - (pr - line));
 			if (pr == NULL)
 				goto done;
 			if (pr == (char *)-1)
@@ -365,8 +373,6 @@
 		/* Parse and execute command line. */
 		if (substparm(line) && !pxline(line, PX_SYNEXEC))
 			error("syntax error");
-		if (tflag)
-			break;
 	}
 
 done:
@@ -509,7 +515,7 @@
 }
 
 /*
- * Read a line from fd, with error checking.
+ * Read a line from the shell's standard input.
  * If read(2) returns -1, terminate the shell w/ non-zero status.
  * If command line overflow occurs in a non-interactive shell,
  * terminate w/ non-zero status.  Otherwise, return -1.
@@ -517,7 +523,7 @@
  * Return NULL at EOF.
  */
 char *
-readline(char *b, int fd, size_t len)
+readline(char *b, size_t len)
 {
 	unsigned char eot;
 	char *end, *p;
@@ -524,7 +530,7 @@
 
 	end = b + len;
 	for (eot = 0, p = b; p < end; p++) {
-		switch (read(fd, p, (size_t)1)) {
+		switch (read(STDIN_FILENO, p, (size_t)1)) {
 		case -1:
 			exit(1);
 		case 0:
@@ -540,18 +546,18 @@
 				write(STDERR_FILENO, "\n", (size_t)1);
 			return(NULL);
 		}
-		eot = 0;
 		if (*p == '\n') {
 			*p = '\0';
 			return(p);
 		}
+		eot = 0;
 	}
 
 	/* Flush all unread characters from the input queue if
 	 * command line overflow occurs and input is from a tty.
 	 */
-	if (isatty(fd))
-		tcflush(fd, TCIFLUSH);
+	if (isatty(STDIN_FILENO))
+		tcflush(STDIN_FILENO, TCIFLUSH);
 	error("Command line overflow");
 	return((char *)-1);
 }
@@ -569,11 +575,8 @@
 	char dbuf[LINELEN], tbuf[32];
 	char *d, *eos, *p, *t;
 
-	if (*(s = de_blank(s)) == '\0')
-		return(1);
-
 	eos = dbuf + LINELEN - 1;
-	for (copy = 0, d = dbuf, p = s; *p != '\0'; d++, p++) {
+	for (copy = 0, d = dbuf, p = de_blank(s); *p != '\0'; d++, p++) {
 
 		/* Skip quoted characters while ignoring `( ... )'. */
 		if ((t = quote(p, 0)) == NULL) {
@@ -1104,7 +1107,7 @@
 		if (!INTERACTIVE) {
 			lseek(STDIN_FILENO, (off_t)0, SEEK_END);
 			if (shtype & (RCFILE | COMMANDFILE))
-				exit(status);
+				DOEXIT(status);
 		}
 		return;
 	case SBILOGIN:
@@ -1311,7 +1314,7 @@
 						continue;
 					lseek(STDIN_FILENO, (off_t)0, SEEK_END);
 					if (shtype & COMMANDFILE)
-						exit(status);
+						DOEXIT(status);
 				}
 
 			} else
@@ -1812,8 +1815,10 @@
 {
 	if (msg != NULL)
 		fprintf(stderr, "%s\n", msg);
-	if (!INTERACTIVE)
+	if (!INTERACTIVE) {
+		lseek(STDIN_FILENO, (off_t)0, SEEK_END);
 		DOEXIT(1);
+	}
 	status = 1;
 }
 
@@ -2023,7 +2028,7 @@
 						lseek(STDIN_FILENO, (off_t)0,
 						    SEEK_END);
 						if (shtype & COMMANDFILE)
-							exit(status);
+							DOEXIT(status);
 					}
 
 				} else