From 1b355ebba68bdd567dd3961a18291dfd9532c2e8 Mon Sep 17 00:00:00 2001
From: Eric Andersen
Date: Tue, 5 Sep 2000 17:37:48 +0000
Subject: Added expr, from Edward Betts <edward@debian.org>, with some fixups
and docs added by me. -Erik
---
AUTHORS | 3 +
TODO | 1 -
applets/busybox.c | 3 +
applets/busybox.sh | 2 +-
applets/usage.c | 38 ++++
busybox.c | 3 +
busybox.def.h | 1 +
busybox.sh | 2 +-
coreutils/expr.c | 531 +++++++++++++++++++++++++++++++++++++++++++++++++++++
coreutils/wc.c | 2 +-
docs/busybox.pod | 41 ++++-
docs/busybox.sgml | 52 ++++++
expr.c | 531 +++++++++++++++++++++++++++++++++++++++++++++++++++++
internal.h | 3 +
usage.c | 38 ++++
wc.c | 2 +-
16 files changed, 1247 insertions(+), 6 deletions(-)
create mode 100644 coreutils/expr.c
create mode 100644 expr.c
diff --git a/AUTHORS b/AUTHORS
index 64114a5..918a001 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -12,6 +12,9 @@ Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
Tons of new stuff, major rewrite of most of the
core apps, tons of new apps as noted in header files.
+Edward Betts <edward@debian.org>
+ expr, hostid, logname, tty, wc, whoami, yes
+
John Beppu <beppu@lineo.com>
du, head, nslookup, sort, tee, uniq
diff --git a/TODO b/TODO
index d345723..b8a2501 100644
--- a/TODO
+++ b/TODO
@@ -22,7 +22,6 @@ around to it some time. If you have any good ideas, please let me know.
* rdate
* hwclock
* stty
-* expr
* wget (or whatever I call it)
* tftp
* ftp
diff --git a/applets/busybox.c b/applets/busybox.c
index 0ffa94e..a7c5d37 100644
--- a/applets/busybox.c
+++ b/applets/busybox.c
@@ -76,6 +76,9 @@ const struct BB_applet applets[] = {
#ifdef BB_ECHO
{"echo", echo_main, _BB_DIR_BIN, echo_usage},
#endif
+#ifdef BB_EXPR
+ {"expr", expr_main, _BB_DIR_USR_BIN, expr_usage},
+#endif
#ifdef BB_TRUE_FALSE
{"false", false_main, _BB_DIR_BIN, false_usage},
#endif
diff --git a/applets/busybox.sh b/applets/busybox.sh
index 5dd6e1c..2b45210 100755
--- a/applets/busybox.sh
+++ b/applets/busybox.sh
@@ -5,6 +5,6 @@
ls -1 ` \
gcc -E -dM busybox.def.h | \
sed -n -e '/^.*BB_FEATURE.*$/d;s/^#define.*\<BB_\(.*\)\>/\1.c/gp;' \
- | tr [:upper:] [:lower:] | sort
+ | tr '[:upper:]' '[:lower:]' | sort
` 2>/dev/null | sed -e 's/\.c$/\.o/g'
diff --git a/applets/usage.c b/applets/usage.c
index 91064f5..05913f3 100644
--- a/applets/usage.c
+++ b/applets/usage.c
@@ -250,6 +250,44 @@ const char echo_usage[] =
;
#endif
+#if defined BB_EXPR
+const char expr_usage[] =
+ "expr EXPRESSION\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+ "\nPrints the value of EXPRESSION to standard output.\n\n"
+ "EXPRESSION may be:\n"
+ "ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2\n"
+ "ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0\n"
+ "ARG1 < ARG2 ARG1 is less than ARG2\n"
+ "ARG1 <= ARG2 ARG1 is less than or equal to ARG2\n"
+ "ARG1 = ARG2 ARG1 is equal to ARG2\n"
+ "ARG1 != ARG2 ARG1 is unequal to ARG2\n"
+ "ARG1 >= ARG2 ARG1 is greater than or equal to ARG2\n"
+ "ARG1 > ARG2 ARG1 is greater than ARG2\n"
+ "ARG1 + ARG2 arithmetic sum of ARG1 and ARG2\n"
+ "ARG1 - ARG2 arithmetic difference of ARG1 and ARG2\n"
+ "ARG1 * ARG2 arithmetic product of ARG1 and ARG2\n"
+ "ARG1 / ARG2 arithmetic quotient of ARG1 divided by ARG2\n"
+ "ARG1 % ARG2 arithmetic remainder of ARG1 divided by ARG2\n"
+ "STRING : REGEXP anchored pattern match of REGEXP in STRING\n"
+ "match STRING REGEXP same as STRING : REGEXP\n"
+ "substr STRING POS LENGTH substring of STRING, POS counted from 1\n"
+ "index STRING CHARS index in STRING where any CHARS is found, or 0\n"
+ "length STRING length of STRING\n"
+ "quote TOKEN interpret TOKEN as a string, even if it is a \n"
+ " keyword like `match' or an operator like `/'\n"
+ "( EXPRESSION ) value of EXPRESSION\n\n"
+ "Beware that many operators need to be escaped or quoted for shells.\n"
+ "Comparisons are arithmetic if both ARGs are numbers, else\n"
+ "lexicographical. Pattern matches return the string matched between \n"
+ "\\( and \\) or null; if \\( and \\) are not used, they return the number \n"
+ "of characters matched or 0.\n"
+
+#endif
+ ;
+#endif
+
+
#if defined BB_TRUE_FALSE
const char false_usage[] =
"false\n"
diff --git a/busybox.c b/busybox.c
index 0ffa94e..a7c5d37 100644
--- a/busybox.c
+++ b/busybox.c
@@ -76,6 +76,9 @@ const struct BB_applet applets[] = {
#ifdef BB_ECHO
{"echo", echo_main, _BB_DIR_BIN, echo_usage},
#endif
+#ifdef BB_EXPR
+ {"expr", expr_main, _BB_DIR_USR_BIN, expr_usage},
+#endif
#ifdef BB_TRUE_FALSE
{"false", false_main, _BB_DIR_BIN, false_usage},
#endif
diff --git a/busybox.def.h b/busybox.def.h
index 3ad118d..f88851a 100644
--- a/busybox.def.h
+++ b/busybox.def.h
@@ -27,6 +27,7 @@
#define BB_DU
#define BB_DUMPKMAP
#define BB_ECHO
+#define BB_EXPR
#define BB_FBSET
#define BB_FDFLUSH
#define BB_FIND
diff --git a/busybox.sh b/busybox.sh
index 5dd6e1c..2b45210 100755
--- a/busybox.sh
+++ b/busybox.sh
@@ -5,6 +5,6 @@
ls -1 ` \
gcc -E -dM busybox.def.h | \
sed -n -e '/^.*BB_FEATURE.*$/d;s/^#define.*\<BB_\(.*\)\>/\1.c/gp;' \
- | tr [:upper:] [:lower:] | sort
+ | tr '[:upper:]' '[:lower:]' | sort
` 2>/dev/null | sed -e 's/\.c$/\.o/g'
diff --git a/coreutils/expr.c b/coreutils/expr.c
new file mode 100644
index 0000000..9e3c04a
--- /dev/null
+++ b/coreutils/expr.c
@@ -0,0 +1,531 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini expr implementation for busybox
+ *
+ * based on GNU expr Mike Parker.
+ * Copyright (C) 86, 1991-1997, 1999 Free Software Foundation, Inc.
+ *
+ * Busybox modifications
+ * Copyright (c) 2000 Edward Betts <edward@debian.org>.
+ *
+ * this program is free software; you can redistribute it and/or modify
+ * it under the terms of the gnu general public license as published by
+ * the free software foundation; either version 2 of the license, or
+ * (at your option) any later version.
+ *
+ * this program is distributed in the hope that it will be useful,
+ * but without any warranty; without even the implied warranty of
+ * merchantability or fitness for a particular purpose. see the gnu
+ * general public license for more details.
+ *
+ * you should have received a copy of the gnu general public license
+ * along with this program; if not, write to the free software
+ * foundation, inc., 59 temple place, suite 330, boston, ma 02111-1307 usa
+ *
+ */
+
+/* This program evaluates expressions. Each token (operator, operand,
+ * parenthesis) of the expression must be a seperate argument. The
+ * parser used is a reasonably general one, though any incarnation of
+ * it is language-specific. It is especially nice for expressions.
+ *
+ * No parse tree is needed; a new node is evaluated immediately.
+ * One function can handle multiple operators all of equal precedence,
+ * provided they all associate ((x op x) op x). */
+
+#include "internal.h"
+#include <stdio.h>
+#include <sys/types.h>
+
+#include <regex.h>
+
+/* The kinds of value we can have. */
+enum valtype {
+ integer,
+ string
+};
+typedef enum valtype TYPE;
+
+/* A value is.... */
+struct valinfo {
+ TYPE type; /* Which kind. */
+ union { /* The value itself. */
+ int i;
+ char *s;
+ } u;
+};
+typedef struct valinfo VALUE;
+
+/* The arguments given to the program, minus the program name. */
+static char **args;
+
+static VALUE *docolon (VALUE *sv, VALUE *pv);
+static VALUE *eval (void);
+static VALUE *int_value (int i);
+static VALUE *str_value (char *s);
+static int nextarg (char *str);
+static int null (VALUE *v);
+static int toarith (VALUE *v);
+static void freev (VALUE *v);
+static void tostring (VALUE *v);
+
+int expr_main (int argc, char **argv)
+{
+ VALUE *v;
+
+ if (argc == 1) {
+ fatalError("too few arguments\n");
+ }
+
+ args = argv + 1;
+
+ v = eval ();
+ if (*args)
+ fatalError ("syntax error\n");
+
+ if (v->type == integer)
+ printf ("%d\n", v->u.i);
+ else
+ printf ("%s\n", v->u.s);
+
+ exit (null (v));
+}
+
+/* Return a VALUE for I. */
+
+static VALUE *int_value (int i)
+{
+ VALUE *v;
+
+ v = xmalloc (sizeof(VALUE));
+ v->type = integer;
+ v->u.i = i;
+ return v;
+}
+
+/* Return a VALUE for S. */
+
+static VALUE *str_value (char *s)
+{
+ VALUE *v;
+
+ v = xmalloc (sizeof(VALUE));
+ v->type = string;
+ v->u.s = strdup (s);
+ return v;
+}
+
+/* Free VALUE V, including structure components. */
+
+static void freev (VALUE *v)
+{
+ if (v->type == string)
+ free (v->u.s);
+ free (v);
+}
+
+/* Return nonzero if V is a null-string or zero-number. */
+
+static int null (VALUE *v)
+{
+ switch (v->type) {
+ case integer:
+ return v->u.i == 0;
+ case string:
+ return v->u.s[0] == '\0' || strcmp (v->u.s, "0") == 0;
+ default:
+ abort ();
+ }
+}
+
+/* Coerce V to a string value (can't fail). */
+
+static void tostring (VALUE *v)
+{
+ char *temp;
+
+ if (v->type == integer) {
+ temp = xmalloc (4 * (sizeof (int) / sizeof (char)));
+ sprintf (temp, "%d", v->u.i);
+ v->u.s = temp;
+ v->type = string;
+ }
+}
+
+/* Coerce V to an integer value. Return 1 on success, 0 on failure. */
+
+static int toarith (VALUE *v)
+{
+ int i;
+
+ switch (v->type) {
+ case integer:
+ return 1;
+ case string:
+ i = 0;
+ /* Don't interpret the empty string as an integer. */
+ if (v->u.s == 0)
+ return 0;
+ i = atoi(v->u.s);
+ free (v->u.s);
+ v->u.i = i;
+ v->type = integer;
+ return 1;
+ default:
+ abort ();
+ }
+}
+
+/* Return nonzero if the next token matches STR exactly.
+ STR must not be NULL. */
+
+static int
+nextarg (char *str)
+{
+ if (*args == NULL)
+ return 0;
+ return strcmp (*args, str) == 0;
+}
+
+/* The comparison operator handling functions. */
+
+#define cmpf(name, rel) \
+static int name (l, r) VALUE *l; VALUE *r; \
+{ \
+ if (l->type == string || r->type == string) { \
+ tostring (l); \
+ tostring (r); \
+ return strcmp (l->u.s, r->u.s) rel 0; \
+ } \
+ else \
+ return l->u.i rel r->u.i; \
+}
+ cmpf (less_than, <)
+ cmpf (less_equal, <=)
+ cmpf (equal, ==)
+ cmpf (not_equal, !=)
+ cmpf (greater_equal, >=)
+ cmpf (greater_than, >)
+
+#undef cmpf
+
+/* The arithmetic operator handling functions. */
+
+#define arithf(name, op) \
+static \
+int name (l, r) VALUE *l; VALUE *r; \
+{ \
+ if (!toarith (l) || !toarith (r)) \
+ fatalError ("non-numeric argument\n"); \
+ return l->u.i op r->u.i; \
+}
+
+#define arithdivf(name, op) \
+int name (l, r) VALUE *l; VALUE *r; \
+{ \
+ if (!toarith (l) || !toarith (r)) \
+ fatalError ( "non-numeric argument\n"); \
+ if (r->u.i == 0) \
+ fatalError ( "division by zero\n"); \
+ return l->u.i op r->u.i; \
+}
+
+ arithf (plus, +)
+ arithf (minus, -)
+ arithf (multiply, *)
+ arithdivf (divide, /)
+ arithdivf (mod, %)
+
+#undef arithf
+#undef arithdivf
+
+/* Do the : operator.
+ SV is the VALUE for the lhs (the string),
+ PV is the VALUE for the rhs (the pattern). */
+
+static VALUE *docolon (VALUE *sv, VALUE *pv)
+{
+ VALUE *v;
+ const char *errmsg;
+ struct re_pattern_buffer re_buffer;
+ struct re_registers re_regs;
+ int len;
+
+ tostring (sv);
+ tostring (pv);
+
+ if (pv->u.s[0] == '^') {
+ fprintf (stderr, "\
+warning: unportable BRE: `%s': using `^' as the first character\n\
+of a basic regular expression is not portable; it is being ignored",
+ pv->u.s);
+ }
+
+ len = strlen (pv->u.s);
+ memset (&re_buffer, 0, sizeof (re_buffer));
+ memset (&re_regs, 0, sizeof (re_regs));
+ re_buffer.allocated = 2 * len;
+ re_buffer.buffer = (unsigned char *) xmalloc (re_buffer.allocated);
+ re_buffer.translate = 0;
+ re_syntax_options = RE_SYNTAX_POSIX_BASIC;
+ errmsg = re_compile_pattern (pv->u.s, len, &re_buffer);
+ if (errmsg) {
+ fatalError("%s\n", errmsg);
+ }
+
+ len = re_match (&re_buffer, sv->u.s, strlen (sv->u.s), 0, &re_regs);
+ if (len >= 0) {
+ /* Were \(...\) used? */
+ if (re_buffer.re_nsub > 0) { /* was (re_regs.start[1] >= 0) */
+ sv->u.s[re_regs.end[1]] = '\0';
+ v = str_value (sv->u.s + re_regs.start[1]);
+ }
+ else
+ v = int_value (len);
+ }
+ else {
+ /* Match failed -- return the right kind of null. */
+ if (re_buffer.re_nsub > 0)
+ v = str_value ("");
+ else
+ v = int_value (0);
+ }
+ free (re_buffer.buffer);
+ return v;
+}
+
+/* Handle bare operands and ( expr ) syntax. */
+
+static VALUE *eval7 (void)
+{
+ VALUE *v;
+
+ if (!*args)
+ fatalError ( "syntax error\n");
+
+ if (nextarg ("(")) {
+ args++;
+ v = eval ();
+ if (!nextarg (")"))
+ fatalError ( "syntax error\n");
+ args++;
+ return v;
+ }
+
+ if (nextarg (")"))
+ fatalError ( "syntax error\n");
+
+ return str_value (*args++);
+}
+
+/* Handle match, substr, index, length, and quote keywords. */
+
+static VALUE *eval6 (void)
+{
+ VALUE *l, *r, *v, *i1, *i2;
+
+ if (nextarg ("quote")) {
+ args++;
+ if (!*args)
+ fatalError ( "syntax error\n");
+ return str_value (*args++);
+ }
+ else if (nextarg ("length")) {
+ args++;
+ r = eval6 ();
+ tostring (r);
+ v = int_value (strlen (r->u.s));
+ freev (r);
+ return v;
+ }
+ else if (nextarg ("match")) {
+ args++;
+ l = eval6 ();
+ r = eval6 ();
+ v = docolon (l, r);
+ freev (l);
+ freev (r);
+ return v;
+ }
+ else if (nextarg ("index")) {
+ args++;
+ l = eval6 ();
+ r = eval6 ();
+ tostring (l);
+ tostring (r);
+ v = int_value (strcspn (l->u.s, r->u.s) + 1);
+ if (v->u.i == (int) strlen (l->u.s) + 1)
+ v->u.i = 0;
+ freev (l);
+ freev (r);
+ return v;
+ }
+ else if (nextarg ("substr")) {
+ args++;
+ l = eval6 ();
+ i1 = eval6 ();
+ i2 = eval6 ();
+ tostring (l);
+ if (!toarith (i1) || !toarith (i2)
+ || i1->u.i > (int) strlen (l->u.s)
+ || i1->u.i <= 0 || i2->u.i <= 0)
+ v = str_value ("");
+ else {
+ v = xmalloc (sizeof(VALUE));
+ v->type = string;
+ v->u.s = strncpy ((char *) xmalloc (i2->u.i + 1),
+ l->u.s + i1->u.i - 1, i2->u.i);
+ v->u.s[i2->u.i] = 0;
+ }
+ freev (l);
+ freev (i1);
+ freev (i2);
+ return v;
+ }
+ else
+ return eval7 ();
+}
+
+/* Handle : operator (pattern matching).
+ Calls docolon to do the real work. */
+
+static VALUE *eval5 (void)
+{
+ VALUE *l, *r, *v;
+
+ l = eval6 ();
+ while (nextarg (":")) {
+ args++;
+ r = eval6 ();
+ v = docolon (l, r);
+ freev (l);
+ freev (r);
+ l = v;
+ }
+ return l;
+}
+
+/* Handle *, /, % operators. */
+
+static VALUE *eval4 (void)
+{
+ VALUE *l, *r;
+ int (*fxn) (), val;
+
+ l = eval5 ();
+ while (1) {
+ if (nextarg ("*"))
+ fxn = multiply;
+ else if (nextarg ("/"))
+ fxn = divide;
+ else if (nextarg ("%"))
+ fxn = mod;
+ else
+ return l;
+ args++;
+ r = eval5 ();
+ val = (*fxn) (l, r);
+ freev (l);
+ freev (r);
+ l = int_value (val);
+ }
+}
+
+/* Handle +, - operators. */
+
+static VALUE *eval3 (void)
+{
+ VALUE *l, *r;
+ int (*fxn) (), val;
+
+ l = eval4 ();
+ while (1) {
+ if (nextarg ("+"))
+ fxn = plus;
+ else if (nextarg ("-"))
+ fxn = minus;
+ else
+ return l;
+ args++;
+ r = eval4 ();
+ val = (*fxn) (l, r);
+ freev (l);
+ freev (r);
+ l = int_value (val);
+ }
+}
+
+/* Handle comparisons. */
+
+static VALUE *eval2 (void)
+{
+ VALUE *l, *r;
+ int (*fxn) (), val;
+
+ l = eval3 ();
+ while (1) {
+ if (nextarg ("<"))
+ fxn = less_than;
+ else if (nextarg ("<="))
+ fxn = less_equal;
+ else if (nextarg ("=") || nextarg ("=="))
+ fxn = equal;
+ else if (nextarg ("!="))
+ fxn = not_equal;
+ else if (nextarg (">="))
+ fxn = greater_equal;
+ else if (nextarg (">"))
+ fxn = greater_than;
+ else
+ return l;
+ args++;
+ r = eval3 ();
+ toarith (l);
+ toarith (r);
+ val = (*fxn) (l, r);
+ freev (l);
+ freev (r);
+ l = int_value (val);
+ }
+}
+
+/* Handle &. */
+
+static VALUE *eval1 (void)
+{
+ VALUE *l, *r;
+
+ l = eval2 ();
+ while (nextarg ("&")) {
+ args++;
+ r = eval2 ();
+ if (null (l) || null (r)) {
+ freev (l);
+ freev (r);
+ l = int_value (0);
+ }
+ else
+ freev (r);
+ }
+ return l;
+}
+
+/* Handle |. */
+
+static VALUE *eval (void)
+{
+ VALUE *l, *r;
+
+ l = eval1 ();
+ while (nextarg ("|")) {
+ args++;
+ r = eval1 ();
+ if (null (l)) {
+ freev (l);
+ l = r;
+ }
+ else
+ freev (r);
+ }
+ return l;
+}
diff --git a/coreutils/wc.c b/coreutils/wc.c
index 02e2b2a..ca5b368 100644
--- a/coreutils/wc.c
+++ b/coreutils/wc.c
@@ -2,7 +2,7 @@
/*
* Mini wc implementation for busybox
*
- * by Edward Betts <edward@debian.org>
+ * Copyright (C) 2000 Edward Betts <edward@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
diff --git a/docs/busybox.pod b/docs/busybox.pod
index accdaed..3bedcef 100644
--- a/docs/busybox.pod
+++ b/docs/busybox.pod
@@ -497,6 +497,45 @@ Example:
-------------------------------
+=item echo
+
+
+Usage: expr EXPRESSION
+
+Prints the value of EXPRESSION to standard output.
+
+EXPRESSION may be:
+
+ ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2
+ ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0
+ ARG1 < ARG2 ARG1 is less than ARG2
+ ARG1 <= ARG2 ARG1 is less than or equal to ARG2
+ ARG1 = ARG2 ARG1 is equal to ARG2
+ ARG1 != ARG2 ARG1 is unequal to ARG2
+ ARG1 >= ARG2 ARG1 is greater than or equal to ARG2
+ ARG1 > ARG2 ARG1 is greater than ARG2
+ ARG1 + ARG2 arithmetic sum of ARG1 and ARG2
+ ARG1 - ARG2 arithmetic difference of ARG1 and ARG2
+ ARG1 * ARG2 arithmetic product of ARG1 and ARG2
+ ARG1 / ARG2 arithmetic quotient of ARG1 divided by ARG2
+ ARG1 % ARG2 arithmetic remainder of ARG1 divided by ARG2
+ STRING : REGEXP anchored pattern match of REGEXP in STRING
+ match STRING REGEXP same as STRING : REGEXP
+ substr STRING POS LENGTH substring of STRING, POS counted from 1
+ index STRING CHARS index in STRING where any CHARS is found, or 0
+ length STRING length of STRING
+ quote TOKEN interpret TOKEN as a string, even if it is a
+ keyword like `match' or an operator like `/'
+ ( EXPRESSION ) value of EXPRESSION
+
+Beware that many operators need to be escaped or quoted for shells.
+Comparisons are arithmetic if both ARGs are numbers, else
+lexicographical. Pattern matches return the string matched between
+\( and \) or null; if \( and \) are not used, they return the number
+of characters matched or 0.
+
+-------------------------------
+
=item false
Returns an exit code of FALSE (1)
@@ -2112,4 +2151,4 @@ Enrique Zanardi <ezanardi@ull.es>
=cut
-# $Id: busybox.pod,v 1.65 2000/09/01 16:12:57 andersen Exp $
+# $Id: busybox.pod,v 1.66 2000/09/05 17:37:48 andersen Exp $
diff --git a/docs/busybox.sgml b/docs/busybox.sgml
index ec6f504..a25aa01 100644
--- a/docs/busybox.sgml
+++ b/docs/busybox.sgml
@@ -879,6 +879,58 @@
</para>
</sect1>
+ <sect1 id="expr">
+ <title>expr</title>
+
+ <para>
+ Usage: expr EXPRESSION
+ </para>
+
+ <para>
+ Prints the value of EXPRESSION to standard output.
+ </para>
+
+ <para>
+ EXPRESSION may be:
+ </para>
+
+ <para>
+ <screen>
+ ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2
+ ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0
+ ARG1 < ARG2 ARG1 is less than ARG2
+ ARG1 <= ARG2 ARG1 is less than or equal to ARG2
+ ARG1 = ARG2 ARG1 is equal to ARG2
+ ARG1 != ARG2 ARG1 is unequal to ARG2
+ ARG1 >= ARG2 ARG1 is greater than or equal to ARG2
+ ARG1 > ARG2 ARG1 is greater than ARG2
+ ARG1 + ARG2 arithmetic sum of ARG1 and ARG2
+ ARG1 - ARG2 arithmetic difference of ARG1 and ARG2
+ ARG1 * ARG2 arithmetic product of ARG1 and ARG2
+ ARG1 / ARG2 arithmetic quotient of ARG1 divided by ARG2
+ ARG1 % ARG2 arithmetic remainder of ARG1 divided by ARG2
+ STRING : REGEXP anchored pattern match of REGEXP in STRING
+ match STRING REGEXP same as STRING : REGEXP
+ substr STRING POS LENGTH substring of STRING, POS counted from 1
+ index STRING CHARS index in STRING where any CHARS is found, or 0
+ length STRING length of STRING
+ quote TOKEN interpret TOKEN as a string, even if it is a
+ keyword like `match' or an operator like `/'
+ ( EXPRESSION ) value of EXPRESSION
+ </screen>
+ </para>
+
+ <para>
+ Beware that many operators need to be escaped or quoted for shells.
+ Comparisons are arithmetic if both ARGs are numbers, else
+ lexicographical. Pattern matches return the string matched between
+ \( and \) or null; if \( and \) are not used, they return the number
+ of characters matched or 0.
+ </para>
+
+ </sect1>
+
+
<sect1 id="false">
<title>false</title>
diff --git a/expr.c b/expr.c
new file mode 100644
index 0000000..9e3c04a
--- /dev/null
+++ b/expr.c
@@ -0,0 +1,531 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini expr implementation for busybox
+ *
+ * based on GNU expr Mike Parker.
+ * Copyright (C) 86, 1991-1997, 1999 Free Software Foundation, Inc.
+ *
+ * Busybox modifications
+ * Copyright (c) 2000 Edward Betts <edward@debian.org>.
+ *
+ * this program is free software; you can redistribute it and/or modify
+ * it under the terms of the gnu general public license as published by
+ * the free software foundation; either version 2 of the license, or
+ * (at your option) any later version.
+ *
+ * this program is distributed in the hope that it will be useful,
+ * but without any warranty; without even the implied warranty of
+ * merchantability or fitness for a particular purpose. see the gnu
+ * general public license for more details.
+ *
+ * you should have received a copy of the gnu general public license
+ * along with this program; if not, write to the free software
+ * foundation, inc., 59 temple place, suite 330, boston, ma 02111-1307 usa
+ *
+ */
+
+/* This program evaluates expressions. Each token (operator, operand,
+ * parenthesis) of the expression must be a seperate argument. The
+ * parser used is a reasonably general one, though any incarnation of
+ * it is language-specific. It is especially nice for expressions.
+ *
+ * No parse tree is needed; a new node is evaluated immediately.
+ * One function can handle multiple operators all of equal precedence,
+ * provided they all associate ((x op x) op x). */
+
+#include "internal.h"
+#include <stdio.h>
+#include <sys/types.h>
+
+#include <regex.h>
+
+/* The kinds of value we can have. */
+enum valtype {
+ integer,
+ string
+};
+typedef enum valtype TYPE;
+
+/* A value is.... */
+struct valinfo {
+ TYPE type; /* Which kind. */
+ union { /* The value itself. */
+ int i;
+ char *s;
+ } u;
+};
+typedef struct valinfo VALUE;
+
+/* The arguments given to the program, minus the program name. */
+static char **args;
+
+static VALUE *docolon (VALUE *sv, VALUE *pv);
+static VALUE *eval (void);
+static VALUE *int_value (int i);
+static VALUE *str_value (char *s);
+static int nextarg (char *str);
+static int null (VALUE *v);
+static int toarith (VALUE *v);
+static void freev (VALUE *v);
+static void tostring (VALUE *v);
+
+int expr_main (int argc, char **argv)
+{
+ VALUE *v;
+
+ if (argc == 1) {
+ fatalError("too few arguments\n");
+ }
+
+ args = argv + 1;
+
+ v = eval ();
+ if (*args)
+ fatalError ("syntax error\n");
+
+ if (v->type == integer)
+ printf ("%d\n", v->u.i);
+ else
+ printf ("%s\n", v->u.s);
+
+ exit (null (v));
+}
+
+/* Return a VALUE for I. */
+
+static VALUE *int_value (int i)
+{
+ VALUE *v;
+
+ v = xmalloc (sizeof(VALUE));
+ v->type = integer;
+ v->u.i = i;
+ return v;
+}
+
+/* Return a VALUE for S. */
+
+static VALUE *str_value (char *s)
+{
+ VALUE *v;
+
+ v = xmalloc (sizeof(VALUE));
+ v->type = string;
+ v->u.s = strdup (s);
+ return v;
+}
+
+/* Free VALUE V, including structure components. */
+
+static void freev (VALUE *v)
+{
+ if (v->type == string)
+ free (v->u.s);
+ free (v);
+}
+
+/* Return nonzero if V is a null-string or zero-number. */
+
+static int null (VALUE *v)
+{
+ switch (v->type) {
+ case integer:
+ return v->u.i == 0;
+ case string:
+ return v->u.s[0] == '\0' || strcmp (v->u.s, "0") == 0;
+ default:
+ abort ();
+ }
+}
+
+/* Coerce V to a string value (can't fail). */
+
+static void tostring (VALUE *v)
+{
+ char *temp;
+
+ if (v->type == integer) {
+ temp = xmalloc (4 * (sizeof (int) / sizeof (char)));
+ sprintf (temp, "%d", v->u.i);
+ v->u.s = temp;
+ v->type = string;
+ }
+}
+
+/* Coerce V to an integer value. Return 1 on success, 0 on failure. */
+
+static int toarith (VALUE *v)
+{
+ int i;
+
+ switch (v->type) {
+ case integer:
+ return 1;
+ case string:
+ i = 0;
+ /* Don't interpret the empty string as an integer. */
+ if (v->u.s == 0)
+ return 0;
+ i = atoi(v->u.s);
+ free (v->u.s);
+ v->u.i = i;
+ v->type = integer;
+ return 1;
+ default:
+ abort ();
+ }
+}
+
+/* Return nonzero if the next token matches STR exactly.
+ STR must not be NULL. */
+
+static int
+nextarg (char *str)
+{
+ if (*args == NULL)
+ return 0;
+ return strcmp (*args, str) == 0;
+}
+
+/* The comparison operator handling functions. */
+
+#define cmpf(name, rel) \
+static int name (l, r) VALUE *l; VALUE *r; \
+{ \
+ if (l->type == string || r->type == string) { \
+ tostring (l); \
+ tostring (r); \
+ return strcmp (l->u.s, r->u.s) rel 0; \
+ } \
+ else \
+ return l->u.i rel r->u.i; \
+}
+ cmpf (less_than, <)
+ cmpf (less_equal, <=)
+ cmpf (equal, ==)
+ cmpf (not_equal, !=)
+ cmpf (greater_equal, >=)
+ cmpf (greater_than, >)
+
+#undef cmpf
+
+/* The arithmetic operator handling functions. */
+
+#define arithf(name, op) \
+static \
+int name (l, r) VALUE *l; VALUE *r; \
+{ \
+ if (!toarith (l) || !toarith (r)) \
+ fatalError ("non-numeric argument\n"); \
+ return l->u.i op r->u.i; \
+}
+
+#define arithdivf(name, op) \
+int name (l, r) VALUE *l; VALUE *r; \
+{ \
+ if (!toarith (l) || !toarith (r)) \
+ fatalError ( "non-numeric argument\n"); \
+ if (r->u.i == 0) \
+ fatalError ( "division by zero\n"); \
+ return l->u.i op r->u.i; \
+}
+
+ arithf (plus, +)
+ arithf (minus, -)
+ arithf (multiply, *)
+ arithdivf (divide, /)
+ arithdivf (mod, %)
+
+#undef arithf
+#undef arithdivf
+
+/* Do the : operator.
+ SV is the VALUE for the lhs (the string),
+ PV is the VALUE for the rhs (the pattern). */
+
+static VALUE *docolon (VALUE *sv, VALUE *pv)
+{
+ VALUE *v;
+ const char *errmsg;
+ struct re_pattern_buffer re_buffer;
+ struct re_registers re_regs;
+ int len;
+
+ tostring (sv);
+ tostring (pv);
+
+ if (pv->u.s[0] == '^') {
+ fprintf (stderr, "\
+warning: unportable BRE: `%s': using `^' as the first character\n\
+of a basic regular expression is not portable; it is being ignored",
+ pv->u.s);
+ }
+
+ len = strlen (pv->u.s);
+ memset (&re_buffer, 0, sizeof (re_buffer));
+ memset (&re_regs, 0, sizeof (re_regs));
+ re_buffer.allocated = 2 * len;
+ re_buffer.buffer = (unsigned char *) xmalloc (re_buffer.allocated);
+ re_buffer.translate = 0;
+ re_syntax_options = RE_SYNTAX_POSIX_BASIC;
+ errmsg = re_compile_pattern (pv->u.s, len, &re_buffer);
+ if (errmsg) {
+ fatalError("%s\n", errmsg);
+ }
+
+ len = re_match (&re_buffer, sv->u.s, strlen (sv->u.s), 0, &re_regs);
+ if (len >= 0) {
+ /* Were \(...\) used? */
+ if (re_buffer.re_nsub > 0) { /* was (re_regs.start[1] >= 0) */
+ sv->u.s[re_regs.end[1]] = '\0';
+ v = str_value (sv->u.s + re_regs.start[1]);
+ }
+ else
+ v = int_value (len);
+ }
+ else {
+ /* Match failed -- return the right kind of null. */
+ if (re_buffer.re_nsub > 0)
+ v = str_value ("");
+ else
+ v = int_value (0);
+ }
+ free (re_buffer.buffer);
+ return v;
+}
+
+/* Handle bare operands and ( expr ) syntax. */
+
+static VALUE *eval7 (void)
+{
+ VALUE *v;
+
+ if (!*args)
+ fatalError ( "syntax error\n");
+
+ if (nextarg ("(")) {
+ args++;
+ v = eval ();
+ if (!nextarg (")"))
+ fatalError ( "syntax error\n");
+ args++;
+ return v;
+ }
+
+ if (nextarg (")"))
+ fatalError ( "syntax error\n");
+
+ return str_value (*args++);
+}
+
+/* Handle match, substr, index, length, and quote keywords. */
+
+static VALUE *eval6 (void)
+{
+ VALUE *l, *r, *v, *i1, *i2;
+
+ if (nextarg ("quote")) {
+ args++;
+ if (!*args)
+ fatalError ( "syntax error\n");
+ return str_value (*args++);
+ }
+ else if (nextarg ("length")) {
+ args++;
+ r = eval6 ();
+ tostring (r);
+ v = int_value (strlen (r->u.s));
+ freev (r);
+ return v;
+ }
+ else if (nextarg ("match")) {
+ args++;
+ l = eval6 ();
+ r = eval6 ();
+ v = docolon (l, r);
+ freev (l);
+ freev (r);
+ return v;
+ }
+ else if (nextarg ("index")) {
+ args++;
+ l = eval6 ();
+ r = eval6 ();
+ tostring (l);
+ tostring (r);
+ v = int_value (strcspn (l->u.s, r->u.s) + 1);
+ if (v->u.i == (int) strlen (l->u.s) + 1)
+ v->u.i = 0;
+ freev (l);
+ freev (r);
+ return v;
+ }
+ else if (nextarg ("substr")) {
+ args++;
+ l = eval6 ();
+ i1 = eval6 ();
+ i2 = eval6 ();
+ tostring (l);
+ if (!toarith (i1) || !toarith (i2)
+ || i1->u.i > (int) strlen (l->u.s)
+ || i1->u.i <= 0 || i2->u.i <= 0)
+ v = str_value ("");
+ else {
+ v = xmalloc (sizeof(VALUE));
+ v->type = string;
+ v->u.s = strncpy ((char *) xmalloc (i2->u.i + 1),
+ l->u.s + i1->u.i - 1, i2->u.i);
+ v->u.s[i2->u.i] = 0;
+ }
+ freev (l);
+ freev (i1);
+ freev (i2);
+ return v;
+ }
+ else
+ return eval7 ();
+}
+
+/* Handle : operator (pattern matching).
+ Calls docolon to do the real work. */
+
+static VALUE *eval5 (void)
+{
+ VALUE *l, *r, *v;
+
+ l = eval6 ();
+ while (nextarg (":")) {
+ args++;
+ r = eval6 ();
+ v = docolon (l, r);
+ freev (l);
+ freev (r);
+ l = v;
+ }
+ return l;
+}
+
+/* Handle *, /, % operators. */
+
+static VALUE *eval4 (void)
+{
+ VALUE *l, *r;
+ int (*fxn) (), val;
+
+ l = eval5 ();
+ while (1) {
+ if (nextarg ("*"))
+ fxn = multiply;
+ else if (nextarg ("/"))
+ fxn = divide;
+ else if (nextarg ("%"))
+ fxn = mod;
+ else
+ return l;
+ args++;
+ r = eval5 ();
+ val = (*fxn) (l, r);
+ freev (l);
+ freev (r);
+ l = int_value (val);
+ }
+}
+
+/* Handle +, - operators. */
+
+static VALUE *eval3 (void)
+{
+ VALUE *l, *r;
+ int (*fxn) (), val;
+
+ l = eval4 ();
+ while (1) {
+ if (nextarg ("+"))
+ fxn = plus;
+ else if (nextarg ("-"))
+ fxn = minus;
+ else
+ return l;
+ args++;
+ r = eval4 ();
+ val = (*fxn) (l, r);
+ freev (l);
+ freev (r);
+ l = int_value (val);
+ }
+}
+
+/* Handle comparisons. */
+
+static VALUE *eval2 (void)
+{
+ VALUE *l, *r;
+ int (*fxn) (), val;
+
+ l = eval3 ();
+ while (1) {
+ if (nextarg ("<"))
+ fxn = less_than;
+ else if (nextarg ("<="))
+ fxn = less_equal;
+ else if (nextarg ("=") || nextarg ("=="))
+ fxn = equal;
+ else if (nextarg ("!="))
+ fxn = not_equal;
+ else if (nextarg (">="))
+ fxn = greater_equal;
+ else if (nextarg (">"))
+ fxn = greater_than;
+ else
+ return l;
+ args++;
+ r = eval3 ();
+ toarith (l);
+ toarith (r);
+ val = (*fxn) (l, r);
+ freev (l);
+ freev (r);
+ l = int_value (val);
+ }
+}
+
+/* Handle &. */
+
+static VALUE *eval1 (void)
+{
+ VALUE *l, *r;
+
+ l = eval2 ();
+ while (nextarg ("&")) {
+ args++;
+ r = eval2 ();
+ if (null (l) || null (r)) {
+ freev (l);
+ freev (r);
+ l = int_value (0);
+ }
+ else
+ freev (r);
+ }
+ return l;
+}
+
+/* Handle |. */
+
+static VALUE *eval (void)
+{
+ VALUE *l, *r;
+
+ l = eval1 ();
+ while (nextarg ("|")) {
+ args++;
+ r = eval1 ();
+ if (null (l)) {
+ freev (l);
+ l = r;
+ }
+ else
+ freev (r);
+ }
+ return l;
+}
diff --git a/internal.h b/internal.h
index 33f101e..b2034da 100644
--- a/internal.h
+++ b/internal.h
@@ -110,6 +110,7 @@ extern const struct BB_applet applets[];
extern int ar_main(int argc, char **argv);
extern int basename_main(int argc, char **argv);
+extern int bogomips_main(int argc, char **argv);
extern int busybox_main(int argc, char** argv);
extern int cat_main(int argc, char** argv);
extern int chmod_chown_chgrp_main(int argc, char** argv);
@@ -129,6 +130,7 @@ extern int du_main(int argc, char** argv);
extern int dumpkmap_main(int argc, char** argv);
extern int dutmp_main(int argc, char** argv);
extern int echo_main(int argc, char** argv);
+extern int expr_main(int argc, char** argv);
extern int false_main(int argc, char** argv);
extern int fbset_main(int argc, char** argv);
extern int fdisk_main(int argc, char** argv);
@@ -240,6 +242,7 @@ extern const char du_usage[];
extern const char dumpkmap_usage[];
extern const char dutmp_usage[];
extern const char echo_usage[];
+extern const char expr_usage[];
extern const char false_usage[];
extern const char fdflush_usage[];
extern const char find_usage[];
diff --git a/usage.c b/usage.c
index 91064f5..05913f3 100644
--- a/usage.c
+++ b/usage.c
@@ -250,6 +250,44 @@ const char echo_usage[] =
;
#endif
+#if defined BB_EXPR
+const char expr_usage[] =
+ "expr EXPRESSION\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+ "\nPrints the value of EXPRESSION to standard output.\n\n"
+ "EXPRESSION may be:\n"
+ "ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2\n"
+ "ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0\n"
+ "ARG1 < ARG2 ARG1 is less than ARG2\n"
+ "ARG1 <= ARG2 ARG1 is less than or equal to ARG2\n"
+ "ARG1 = ARG2 ARG1 is equal to ARG2\n"
+ "ARG1 != ARG2 ARG1 is unequal to ARG2\n"
+ "ARG1 >= ARG2 ARG1 is greater than or equal to ARG2\n"
+ "ARG1 > ARG2 ARG1 is greater than ARG2\n"
+ "ARG1 + ARG2 arithmetic sum of ARG1 and ARG2\n"
+ "ARG1 - ARG2 arithmetic difference of ARG1 and ARG2\n"
+ "ARG1 * ARG2 arithmetic product of ARG1 and ARG2\n"
+ "ARG1 / ARG2 arithmetic quotient of ARG1 divided by ARG2\n"
+ "ARG1 % ARG2 arithmetic remainder of ARG1 divided by ARG2\n"
+ "STRING : REGEXP anchored pattern match of REGEXP in STRING\n"
+ "match STRING REGEXP same as STRING : REGEXP\n"
+ "substr STRING POS LENGTH substring of STRING, POS counted from 1\n"
+ "index STRING CHARS index in STRING where any CHARS is found, or 0\n"
+ "length STRING length of STRING\n"
+ "quote TOKEN interpret TOKEN as a string, even if it is a \n"
+ " keyword like `match' or an operator like `/'\n"
+ "( EXPRESSION ) value of EXPRESSION\n\n"
+ "Beware that many operators need to be escaped or quoted for shells.\n"
+ "Comparisons are arithmetic if both ARGs are numbers, else\n"
+ "lexicographical. Pattern matches return the string matched between \n"
+ "\\( and \\) or null; if \\( and \\) are not used, they return the number \n"
+ "of characters matched or 0.\n"
+
+#endif
+ ;
+#endif
+
+
#if defined BB_TRUE_FALSE
const char false_usage[] =
"false\n"
diff --git a/wc.c b/wc.c
index 02e2b2a..ca5b368 100644
--- a/wc.c
+++ b/wc.c
@@ -2,7 +2,7 @@
/*
* Mini wc implementation for busybox
*
- * by Edward Betts <edward@debian.org>
+ * Copyright (C) 2000 Edward Betts <edward@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
--
cgit v1.1