Implement -e expression, for command line expression evaluation.

ok deraadt@

4 files changed, 93 insertions, 37 deletions

diff --git a/usr.bin/bc/bc.1 b/usr.bin/bc/bc.1
index 018822e48c2..990e2baffac 100644
--- a/usr.bin/bc/bc.1
+++ b/usr.bin/bc/bc.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: bc.1,v 1.17 2004/08/25 21:59:59 jmc Exp $
+.\"	$OpenBSD: bc.1,v 1.18 2004/10/19 07:36:51 otto Exp $
 .\"
 .\" Copyright (C) Caldera International Inc.  2001-2002.
 .\" All rights reserved.
@@ -42,13 +42,14 @@
 .Sh SYNOPSIS
 .Nm bc
 .Op Fl cl
+.Op Fl e Ar expression
 .Op Ar file ...
 .Sh DESCRIPTION
 .Nm
 is an interactive processor for a language which resembles
 C but provides unlimited precision arithmetic.
-It takes input from any files given, then reads
-the standard input.
+It takes input from any expressions on the command line and
+any files given, then reads the standard input.
 .Pp
 Options available:
 .Bl -tag -width Ds
@@ -66,9 +67,17 @@ instructions are sent to the standard output,
 instead of being interpreted by a running
 .Xr dc 1
 process.
+.It Fl e Ar expression
+Evaluate
+.Ar expression .
+If multiple
+.Fl e
+options are specified, they are processed in the order given,
+separated by newlines.
 .It Fl l
-Allow specification
-of an arbitrary precision math library.
+Allow specification of an arbitrary precision math library.
+The definitions in the library are available to command line
+expressions.
 .El
 .Pp
 The syntax for
@@ -322,6 +331,12 @@ the exponential function and
 .Pp
 prints approximate values of the exponential function of
 the first ten integers.
+.Pp
+.Bd -literal -offset indent
+$ bc -l -e 'scale = 500; 2 * a(2^10000)' -e quit
+.Ed
+.Pp
+prints an approximation of pi.
 .Sh FILES
 .Bl -tag -width /usr/share/misc/bc.library -compact
 .It Pa /usr/share/misc/bc.library
diff --git a/usr.bin/bc/bc.y b/usr.bin/bc/bc.y
index 31d844e9f07..97482102909 100644
--- a/usr.bin/bc/bc.y
+++ b/usr.bin/bc/bc.y
@@ -1,5 +1,5 @@
 %{
-/*	$OpenBSD: bc.y,v 1.23 2004/02/18 07:43:58 otto Exp $	*/
+/*	$OpenBSD: bc.y,v 1.24 2004/10/19 07:36:51 otto Exp $	*/
 
 /*
  * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
@@ -31,7 +31,7 @@
  */
 
 #ifndef lint
-static const char rcsid[] = "$OpenBSD: bc.y,v 1.23 2004/02/18 07:43:58 otto Exp $";
+static const char rcsid[] = "$OpenBSD: bc.y,v 1.24 2004/10/19 07:36:51 otto Exp $";
 #endif /* not lint */
 
 #include <ctype.h>
@@ -62,6 +62,12 @@ struct tree {
 int			yyparse(void);
 int			yywrap(void);
 
+int			fileindex;
+int			sargc;
+char			**sargv;
+char			*filename;
+char			*cmdexpr;
+
 static void		grow(void);
 static ssize_t		cs(const char *);
 static ssize_t		as(const char *);
@@ -94,10 +100,6 @@ static ssize_t		prologue;
 static ssize_t		epilogue;
 static bool		st_has_continue;
 static char		str_table[UCHAR_MAX][2];
-static int		fileindex;
-static int		sargc;
-static char		**sargv;
-static char		*filename;
 static bool		do_fork = true;
 static u_short		var_count;
 
@@ -921,26 +923,6 @@ add_local(ssize_t n)
 	epilogue = node(epilogue, cs("L"), n, cs("s."), END_NODE);
 }
 
-int
-yywrap(void)
-{
-	if (fileindex < sargc) {
-		filename = sargv[fileindex++];
-		yyin = fopen(filename, "r");
-		lineno = 1;
-		if (yyin == NULL)
-			err(1, "cannot open %s", filename);
-		return 0;
-	} else if (fileindex == sargc) {
-		fileindex++;
-		yyin = stdin;
-		lineno = 1;
-		filename = "stdin";
-		return 0;
-	}
-	return 1;
-}
-
 void
 yyerror(char *s)
 {
@@ -994,7 +976,8 @@ init(void)
 static __dead void
 usage(void)
 {
-	fprintf(stderr, "%s: usage: [-cl] [file ...]\n", __progname);
+	fprintf(stderr, "%s: usage: [-cl] [-e expression] [file ...]\n",
+	    __progname);
 	exit(1);
 }
 
@@ -1058,6 +1041,7 @@ main(int argc, char *argv[])
 {
 	int	i, ch, ret;
 	int	p[2];
+	char	*q;
 
 	init();
 	setlinebuf(stdout);
@@ -1066,13 +1050,21 @@ main(int argc, char *argv[])
 	if (sargv == NULL)
 		err(1, NULL);
 
-	/* The d debug option is 4.4 BSD dc(1) compatible */
-	while ((ch = getopt(argc, argv, "cdl")) != -1) {
+	if ((cmdexpr = strdup("")) == NULL)
+		err(1, NULL);
+	/* The d debug option is 4.4 BSD bc(1) compatible */
+	while ((ch = getopt(argc, argv, "cde:l")) != -1) {
 		switch (ch) {
 		case 'c':
 		case 'd':
 			do_fork = false;
 			break;
+		case 'e':
+			q = cmdexpr;
+			if (asprintf(&cmdexpr, "%s%s\n", cmdexpr, optarg) == -1)
+				err(1, NULL);
+			free(q);
+			break;
 		case 'l':
 			sargv[sargc++] = _PATH_LIBB;
 			break;
diff --git a/usr.bin/bc/extern.h b/usr.bin/bc/extern.h
index cc99d12adfa..fc2f5ee5b71 100644
--- a/usr.bin/bc/extern.h
+++ b/usr.bin/bc/extern.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: extern.h,v 1.4 2003/12/02 09:00:07 otto Exp $	*/
+/*      $OpenBSD: extern.h,v 1.5 2004/10/19 07:36:51 otto Exp $	*/
 
 /*
  * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
@@ -31,3 +31,8 @@ void		abort_line(int);
 extern int	lineno;
 extern char	*yytext;
 extern FILE	*yyin;
+extern int	fileindex;
+extern int	sargc;
+extern char	**sargv;
+extern char	*filename;
+extern char	*cmdexpr;
diff --git a/usr.bin/bc/scan.l b/usr.bin/bc/scan.l
index 1e8a3ebaf13..31058afb41f 100644
--- a/usr.bin/bc/scan.l
+++ b/usr.bin/bc/scan.l
@@ -1,5 +1,5 @@
 %{
-/*      $OpenBSD: scan.l,v 1.14 2003/12/02 09:00:07 otto Exp $	*/
+/*      $OpenBSD: scan.l,v 1.15 2004/10/19 07:36:51 otto Exp $	*/
 
 /*
  * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
@@ -18,7 +18,7 @@
  */
 
 #ifndef lint
-static const char rcsid[] = "$OpenBSD: scan.l,v 1.14 2003/12/02 09:00:07 otto Exp $";
+static const char rcsid[] = "$OpenBSD: scan.l,v 1.15 2004/10/19 07:36:51 otto Exp $";
 #endif /* not lint */
 
 #include <err.h>
@@ -26,6 +26,7 @@ static const char rcsid[] = "$OpenBSD: scan.l,v 1.14 2003/12/02 09:00:07 otto Ex
 #include <string.h>
 
 #include "extern.h"
+#include "pathnames.h"
 #include "y.tab.h"
 
 int		lineno;
@@ -227,3 +228,46 @@ abort_line(int sig)
 		printf("[\n]P\n");
 	}
 }
+
+int
+yywrap(void)
+{
+	static int state;
+	static YY_BUFFER_STATE buf;
+
+	if (fileindex == 0 && sargc > 0 && strcmp(sargv[0], _PATH_LIBB) == 0) {
+		filename = sargv[fileindex++];
+		yyin = fopen(filename, "r");
+		lineno = 1;
+		if (yyin == NULL)
+			err(1, "cannot open %s", filename);
+		return (0);
+	}
+	if (state == 0 && cmdexpr[0] != '\0') {
+		buf = yy_scan_string(cmdexpr);
+		state++;
+		lineno = 1;
+		filename = "command line";
+		return (0);
+	} else if (state == 1) {
+		yy_delete_buffer(buf);
+		free(cmdexpr);
+		state++;
+	}
+	if (fileindex < sargc) {
+		filename = sargv[fileindex++];
+		yyin = fopen(filename, "r");
+		lineno = 1;
+		if (yyin == NULL)
+			err(1, "cannot open %s", filename);
+		return (0);
+	} else if (fileindex == sargc) {
+		fileindex++;
+		yyin = stdin;
+		lineno = 1;
+		filename = "stdin";
+		return (0);
+	}
+	return (1);
+}
+