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authorMike Frysinger2009-04-07 06:03:22 +0000
committerMike Frysinger2009-04-07 06:03:22 +0000
commita4f331d3c3ea5b358613992a48556cc9cbfdf139 (patch)
tree316143ec21a1efd2eb7e135121134c0b8b86221e
parent6c9be7f4518bf5594f5b9aaf981ed5dcc4a6939c (diff)
downloadbusybox-a4f331d3c3ea5b358613992a48556cc9cbfdf139.zip
busybox-a4f331d3c3ea5b358613992a48556cc9cbfdf139.tar.gz
implement support for parameter substitution via #/% operators
-rw-r--r--shell/Kbuild2
-rw-r--r--shell/hush.c65
-rw-r--r--shell/hush_test/hush-vars/var_posix1.right17
-rwxr-xr-xshell/hush_test/hush-vars/var_posix1.tests21
-rw-r--r--shell/match.c141
-rw-r--r--shell/match.h22
6 files changed, 243 insertions, 25 deletions
diff --git a/shell/Kbuild b/shell/Kbuild
index 2b461b3..8b693ec 100644
--- a/shell/Kbuild
+++ b/shell/Kbuild
@@ -6,7 +6,7 @@
lib-y:=
lib-$(CONFIG_ASH) += ash.o ash_ptr_hack.o
-lib-$(CONFIG_HUSH) += hush.o
+lib-$(CONFIG_HUSH) += hush.o match.o
lib-$(CONFIG_MSH) += msh.o
lib-$(CONFIG_CTTYHACK) += cttyhack.o
lib-$(CONFIG_SH_MATH_SUPPORT) += math.o
diff --git a/shell/hush.c b/shell/hush.c
index 7928869..1740187 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -43,7 +43,6 @@
* Here Documents ( << word )
* Functions
* Tilde Expansion
- * Parameter Expansion for substring processing ${var#word} ${var%word}
*
* Bash stuff (maybe optionally enable?):
* &> and >& redirection of stdout+stderr
@@ -76,6 +75,7 @@
#include <fnmatch.h>
#endif
#include "math.h"
+#include "match.h"
#ifdef WANT_TO_TEST_NOMMU
# undef BB_MMU
@@ -1667,8 +1667,9 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
char first_ch, ored_ch;
int i;
const char *val;
- char *p;
+ char *dyn_val, *p;
+ dyn_val = NULL;
ored_ch = 0;
debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
@@ -1844,7 +1845,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
++var;
} else {
/* maybe handle parameter expansion */
- exp_off = strcspn(var, ":-=+?");
+ exp_off = strcspn(var, ":-=+?%#");
if (!var[exp_off])
exp_off = 0;
if (exp_off) {
@@ -1873,29 +1874,45 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
val = utoa(val ? strlen(val) : 0);
debug_printf_expand("%s\n", val);
} else if (exp_off) {
- /* we need to do an expansion */
- int exp_test = (!val || (exp_null && !val[0]));
- if (exp_op == '+')
- exp_test = !exp_test;
- debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
- exp_null ? "true" : "false", exp_test);
- if (exp_test) {
- if (exp_op == '?')
- maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
+ if (exp_op == '%' || exp_op == '#') {
+ /* we need to do a pattern match */
+ bool zero;
+ char *loc;
+ scan_t scan = pick_scan(exp_op, *exp_word, &zero);
+ if (exp_op == *exp_word) /* ## or %% */
+ ++exp_word;
+ val = dyn_val = xstrdup(val);
+ loc = scan(dyn_val, exp_word, zero);
+ if (zero)
+ val = loc;
else
- val = exp_word;
-
- if (exp_op == '=') {
- if (isdigit(var[0]) || var[0] == '#') {
- maybe_die(var, "special vars cannot assign in this way");
- val = NULL;
- } else {
- char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
- sprintf(new_var, "%s=%s", var, val);
- set_local_var(new_var, -1, 0);
+ *loc = '\0';
+ } else {
+ /* we need to do an expansion */
+ int exp_test = (!val || (exp_null && !val[0]));
+ if (exp_op == '+')
+ exp_test = !exp_test;
+ debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
+ exp_null ? "true" : "false", exp_test);
+ if (exp_test) {
+ if (exp_op == '?')
+ maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
+ else
+ val = exp_word;
+
+ if (exp_op == '=') {
+ if (isdigit(var[0]) || var[0] == '#') {
+ maybe_die(var, "special vars cannot assign in this way");
+ val = NULL;
+ } else {
+ char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
+ sprintf(new_var, "%s=%s", var, val);
+ set_local_var(new_var, -1, 0);
+ }
}
}
}
+
var[exp_off] = exp_save;
}
@@ -1921,6 +1938,8 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
if (val) {
o_addQstr(output, val, strlen(val));
}
+ free(dyn_val);
+ dyn_val = NULL;
/* Do the check to avoid writing to a const string */
if (*p != SPECIAL_VAR_SYMBOL)
*p = SPECIAL_VAR_SYMBOL;
@@ -4428,7 +4447,6 @@ static int handle_dollar(o_string *as_string,
break;
}
goto case_default;
-#if 0 /* not implemented yet :( */
case '#': /* remove prefix */
case '%': /* remove suffix */
if (expansion == 0) {
@@ -4437,7 +4455,6 @@ static int handle_dollar(o_string *as_string,
break;
}
goto case_default;
-#endif
case '-': /* default value */
case '=': /* assign default */
case '+': /* alternative */
diff --git a/shell/hush_test/hush-vars/var_posix1.right b/shell/hush_test/hush-vars/var_posix1.right
new file mode 100644
index 0000000..55f3579
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_posix1.right
@@ -0,0 +1,17 @@
+abcdcd
+abcdcd
+abcdcd
+cdcd
+babcdcd
+babcdcd
+ababcdcd
+
+ababcd
+ababcd
+ababcd
+abab
+ababcdc
+ababcdc
+ababcdcd
+
+end
diff --git a/shell/hush_test/hush-vars/var_posix1.tests b/shell/hush_test/hush-vars/var_posix1.tests
new file mode 100755
index 0000000..4139e2c
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_posix1.tests
@@ -0,0 +1,21 @@
+var=ababcdcd
+
+echo ${var#ab}
+echo ${var##ab}
+echo ${var#a*b}
+echo ${var##a*b}
+echo ${var#?}
+echo ${var##?}
+echo ${var#*}
+echo ${var##*}
+
+echo ${var%cd}
+echo ${var%%cd}
+echo ${var%c*d}
+echo ${var%%c*d}
+echo ${var%?}
+echo ${var%%?}
+echo ${var%*}
+echo ${var%%*}
+
+echo end
diff --git a/shell/match.c b/shell/match.c
new file mode 100644
index 0000000..0810fd8
--- /dev/null
+++ b/shell/match.c
@@ -0,0 +1,141 @@
+/*
+ * ##/%% variable matching code ripped out of ash shell for code sharing
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
+ * was re-ported from NetBSD and debianized.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ *
+ * Original BSD copyright notice is retained at the end of this file.
+ */
+
+#ifdef STANDALONE
+# include <stdbool.h>
+# include <stdio.h>
+# include <stdlib.h>
+# include <string.h>
+# include <unistd.h>
+#else
+# include "busybox.h"
+#endif
+#include <fnmatch.h>
+#include "match.h"
+
+#define pmatch(a, b) !fnmatch((a), (b), 0)
+
+char *scanleft(char *string, char *pattern, bool zero)
+{
+ char c;
+ char *loc = string;
+
+ do {
+ int match;
+ const char *s;
+
+ c = *loc;
+ if (zero) {
+ *loc = '\0';
+ s = string;
+ } else
+ s = loc;
+ match = pmatch(pattern, s);
+ *loc = c;
+
+ if (match)
+ return loc;
+
+ loc++;
+ } while (c);
+
+ return NULL;
+}
+
+char *scanright(char *string, char *pattern, bool zero)
+{
+ char c;
+ char *loc = string + strlen(string);
+
+ while (loc >= string) {
+ int match;
+ const char *s;
+
+ c = *loc;
+ if (zero) {
+ *loc = '\0';
+ s = string;
+ } else
+ s = loc;
+ match = pmatch(pattern, s);
+ *loc = c;
+
+ if (match)
+ return loc;
+
+ loc--;
+ }
+
+ return NULL;
+}
+
+#ifdef STANDALONE
+int main(int argc, char *argv[])
+{
+ char *string;
+ char *op;
+ char *pattern;
+ bool zero;
+ char *loc;
+
+ int i;
+
+ if (argc == 1) {
+ puts(
+ "Usage: match <test> [test...]\n\n"
+ "Where a <test> is the form: <string><op><match>\n"
+ "This is to test the shell ${var#val} expression type.\n\n"
+ "e.g. `match 'abc#a*'` -> bc"
+ );
+ return 1;
+ }
+
+ for (i = 1; i < argc; ++i) {
+ size_t off;
+ scan_t scan;
+
+ printf("'%s': ", argv[i]);
+
+ string = strdup(argv[i]);
+ off = strcspn(string, "#%");
+ if (!off) {
+ printf("invalid format\n");
+ free(string);
+ continue;
+ }
+ op = string + off;
+ scan = pick_scan(op[0], op[1], &zero);
+ pattern = op + 1;
+ if (op[0] == op[1])
+ op[1] = '\0', ++pattern;
+ op[0] = '\0';
+
+ loc = scan(string, pattern, zero);
+
+ if (zero) {
+ printf("'%s'\n", loc);
+ } else {
+ *loc = '\0';
+ printf("'%s'\n", string);
+ }
+
+ free(string);
+ }
+
+ return 0;
+}
+#endif
diff --git a/shell/match.h b/shell/match.h
new file mode 100644
index 0000000..863f525
--- /dev/null
+++ b/shell/match.h
@@ -0,0 +1,22 @@
+/* match.h - interface to shell ##/%% matching code */
+
+typedef char *(*scan_t)(char *string, char *match, bool zero);
+
+char *scanleft(char *string, char *match, bool zero);
+char *scanright(char *string, char *match, bool zero);
+
+static inline scan_t pick_scan(char op1, char op2, bool *zero)
+{
+ /* # - scanleft
+ * ## - scanright
+ * % - scanright
+ * %% - scanleft
+ */
+ if (op1 == '#') {
+ *zero = true;
+ return op1 == op2 ? scanright : scanleft;
+ } else {
+ *zero = false;
+ return op1 == op2 ? scanleft : scanright;
+ }
+}