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authorJohn Beppu2000-06-21 19:06:16 +0000
committerJohn Beppu2000-06-21 19:06:16 +0000
commit0021679b0dc5767e0c023b28b36eeb1476dc2364 (patch)
tree04ff8031a2151a0f95040bbc4bdf2f616d68a540
parentb405dfa54df117201d93dcb7d24e9e9873737da6 (diff)
downloadbusybox-0021679b0dc5767e0c023b28b36eeb1476dc2364.zip
busybox-0021679b0dc5767e0c023b28b36eeb1476dc2364.tar.gz
+ added dc (aka the function formerly known as math)
+ did all the housekeeping that this change requires.
-rw-r--r--Changelog2
-rw-r--r--applets/busybox.c3
-rw-r--r--busybox.c3
-rw-r--r--busybox.def.h2
-rw-r--r--dc.c (renamed from math.c)6
-rw-r--r--docs/busybox.pod51
-rw-r--r--internal.h1
-rw-r--r--miscutils/dc.c194
8 files changed, 234 insertions, 28 deletions
diff --git a/Changelog b/Changelog
index 07fd30d..8e8de95 100644
--- a/Changelog
+++ b/Changelog
@@ -86,6 +86,8 @@
* Fixed grep "Line too long" problem -- John Beppu
* Fixed 'grep -q -i B some_file' so it works
* math takes input from stdin if no args are given. -- John Beppu
+ * math was renamed to dc. Although it deviates from dc's behaviour,
+ this will probably be remedied in the future. -- John Beppu
-Erik Andersen
diff --git a/applets/busybox.c b/applets/busybox.c
index 191dee1..221ef2a 100644
--- a/applets/busybox.c
+++ b/applets/busybox.c
@@ -72,6 +72,9 @@ const struct BB_applet applets[] = {
#ifdef BB_DATE
{"date", date_main, _BB_DIR_BIN},
#endif
+#ifdef BB_DC
+ {"dc", dc_main, _BB_DIR_USR_BIN},
+#endif
#ifdef BB_DD
{"dd", dd_main, _BB_DIR_BIN},
#endif
diff --git a/busybox.c b/busybox.c
index 191dee1..221ef2a 100644
--- a/busybox.c
+++ b/busybox.c
@@ -72,6 +72,9 @@ const struct BB_applet applets[] = {
#ifdef BB_DATE
{"date", date_main, _BB_DIR_BIN},
#endif
+#ifdef BB_DC
+ {"dc", dc_main, _BB_DIR_USR_BIN},
+#endif
#ifdef BB_DD
{"dd", dd_main, _BB_DIR_BIN},
#endif
diff --git a/busybox.def.h b/busybox.def.h
index d7756a4..89172ea 100644
--- a/busybox.def.h
+++ b/busybox.def.h
@@ -17,6 +17,7 @@
#define BB_CP_MV
#define BB_CUT
#define BB_DATE
+#define BB_DC
#define BB_DD
#define BB_DEALLOCVT
#define BB_DF
@@ -54,7 +55,6 @@
#define BB_LS
#define BB_LSMOD
#define BB_MAKEDEVS
-#define BB_MATH
//#define BB_MD5SUM
#define BB_MKDIR
#define BB_MKFIFO
diff --git a/math.c b/dc.c
index 15a826c..37c7731 100644
--- a/math.c
+++ b/dc.c
@@ -8,7 +8,7 @@
/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
-static const char math_usage[] = "math expression ...\n"
+static const char dc_usage[] = "math expression ...\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
"\nThis is a Tiny RPN calculator that understands the\n"
"following operations: +, -, /, *, and, or, not, eor.\n"
@@ -162,7 +162,7 @@ static int number_of_tokens(char *buffer)
return i;
}
-int math_main(int argc, char **argv)
+int dc_main(int argc, char **argv)
{
/* take stuff from stdin if no args are given */
if (argc <= 1) {
@@ -182,7 +182,7 @@ int math_main(int argc, char **argv)
}
} else {
if (*argv[1]=='-')
- usage(math_usage);
+ usage(dc_usage);
while (argc >= 2) {
stack_machine(argv[1]);
argv++;
diff --git a/docs/busybox.pod b/docs/busybox.pod
index 8b1b715..75763d3 100644
--- a/docs/busybox.pod
+++ b/docs/busybox.pod
@@ -313,6 +313,32 @@ Example:
-------------------------------
+=item dc
+
+Usage: dc expression ...
+
+This is a Tiny RPN calculator that understands the
+following operations: +, -, /, *, and, or, not, eor.
+If no arguments are given, dc will process input from STDIN.
+
+The behaviour of BusyBox/dc deviates (just a little ;-) from
+GNU/dc, but this will be remedied in the future.
+
+Example:
+
+ $ dc 2 2 +
+ 4
+ $ dc 8 8 \* 2 2 + /
+ 16
+ $ dc 0 1 and
+ 0
+ $ dc 0 1 or
+ 1
+ $ echo 72 9 div 8 mul | dc
+ 64
+
+-------------------------------
+
=item dd
Usage: dd [if=name] [of=name] [bs=n] [count=n] [skip=n] [seek=n]
@@ -1012,29 +1038,6 @@ Example:
-------------------------------
-=item math
-
-Usage: math expression ...
-
-This is a Tiny RPN calculator that understands the
-following operations: +, -, /, *, and, or, not, eor.
-If no arguments are given, math will process input from STDIN.
-
-Example:
-
- $ math 2 2 +
- 4
- $ math 8 8 \* 2 2 + /
- 16
- $ math 0 1 and
- 0
- $ math 0 1 or
- 1
- $ echo 72 9 / | math
- 8
-
--------------------------------
-
=item md5sum
Usage: md5sum [OPTION] [file ...]
@@ -2021,4 +2024,4 @@ Enrique Zanardi <ezanardi@ull.es>
=cut
-# $Id: busybox.pod,v 1.43 2000/06/20 00:11:07 proski Exp $
+# $Id: busybox.pod,v 1.44 2000/06/21 19:06:16 beppu Exp $
diff --git a/internal.h b/internal.h
index 50bb17a..58f68f5 100644
--- a/internal.h
+++ b/internal.h
@@ -113,6 +113,7 @@ extern int clear_main(int argc, char** argv);
extern int cp_mv_main(int argc, char** argv);
extern int cut_main(int argc, char** argv);
extern int date_main(int argc, char** argv);
+extern int dc_main(int argc, char** argv);
extern int dd_main(int argc, char** argv);
extern int dirname_main(int argc, char** argv);
extern int deallocvt_main(int argc, char** argv);
diff --git a/miscutils/dc.c b/miscutils/dc.c
new file mode 100644
index 0000000..37c7731
--- /dev/null
+++ b/miscutils/dc.c
@@ -0,0 +1,194 @@
+/* vi: set sw=4 ts=4: */
+#include "internal.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <math.h>
+
+/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
+
+static const char dc_usage[] = "math expression ...\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+ "\nThis is a Tiny RPN calculator that understands the\n"
+ "following operations: +, -, /, *, and, or, not, eor.\n"
+ "i.e. 'math 2 2 add' -> 4, and 'math 8 8 \\* 2 2 + /' -> 16\n"
+#endif
+ ;
+
+static double stack[100];
+static unsigned int pointer;
+
+static void push(double a)
+{
+ if (pointer >= (sizeof(stack) / sizeof(*stack))) {
+ fprintf(stderr, "math: stack overflow\n");
+ exit(-1);
+ } else
+ stack[pointer++] = a;
+}
+
+static double pop()
+{
+ if (pointer == 0) {
+ fprintf(stderr, "math: stack underflow\n");
+ exit(-1);
+ }
+ return stack[--pointer];
+}
+
+static void add()
+{
+ push(pop() + pop());
+}
+
+static void sub()
+{
+ double subtrahend = pop();
+
+ push(pop() - subtrahend);
+}
+
+static void mul()
+{
+ push(pop() * pop());
+}
+
+static void divide()
+{
+ double divisor = pop();
+
+ push(pop() / divisor);
+}
+
+static void and()
+{
+ push((unsigned int) pop() & (unsigned int) pop());
+}
+
+static void or()
+{
+ push((unsigned int) pop() | (unsigned int) pop());
+}
+
+static void eor()
+{
+ push((unsigned int) pop() ^ (unsigned int) pop());
+}
+
+static void not()
+{
+ push(~(unsigned int) pop());
+}
+
+static void print()
+{
+ printf("%g\n", pop());
+}
+
+struct op {
+ const char *name;
+ void (*function) ();
+};
+
+static const struct op operators[] = {
+ {"+", add},
+ {"add", add},
+ {"-", sub},
+ {"sub", sub},
+ {"*", mul},
+ {"mul", mul},
+ {"/", divide},
+ {"div", divide},
+ {"and", and},
+ {"or", or},
+ {"not", not},
+ {"eor", eor},
+ {0, 0}
+};
+
+static void stack_machine(const char *argument)
+{
+ char *endPointer = 0;
+ double d;
+ const struct op *o = operators;
+
+ if (argument == 0) {
+ print();
+ return;
+ }
+
+ d = strtod(argument, &endPointer);
+
+ if (endPointer != argument) {
+ push(d);
+ return;
+ }
+
+ while (o->name != 0) {
+ if (strcmp(o->name, argument) == 0) {
+ (*(o->function)) ();
+ return;
+ }
+ o++;
+ }
+ fprintf(stderr, "math: %s: syntax error.\n", argument);
+ exit(-1);
+}
+
+/* return pointer to next token in buffer and set *buffer to one char
+ * past the end of the above mentioned token
+ */
+static char *get_token(char **buffer)
+{
+ char *start = NULL;
+ char *current = *buffer;
+
+ while (isspace(*current)) { current++; }
+ if (*current != 0) {
+ start = current;
+ while (!isspace(*current) && current != 0) { current++; }
+ *buffer = current;
+ }
+ return start;
+}
+
+/* In Perl one might say, scalar m|\s*(\S+)\s*|g */
+static int number_of_tokens(char *buffer)
+{
+ int i = 0;
+ char *b = buffer;
+ while (get_token(&b)) { i++; }
+ return i;
+}
+
+int dc_main(int argc, char **argv)
+{
+ /* take stuff from stdin if no args are given */
+ if (argc <= 1) {
+ int i, len;
+ char *line = NULL;
+ char *cursor = NULL;
+ char *token = NULL;
+ while ((line = cstring_lineFromFile(stdin))) {
+ cursor = line;
+ len = number_of_tokens(line);
+ for (i = 0; i < len; i++) {
+ token = get_token(&cursor);
+ *cursor++ = 0;
+ stack_machine(token);
+ }
+ free(line);
+ }
+ } else {
+ if (*argv[1]=='-')
+ usage(dc_usage);
+ while (argc >= 2) {
+ stack_machine(argv[1]);
+ argv++;
+ argc--;
+ }
+ }
+ stack_machine(0);
+ return( TRUE);
+}