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authorDenys Vlasenko <vda.linux@googlemail.com>2010-05-20 23:15:42 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-05-20 23:15:42 (GMT)
commit4d8e5fdc1d4bb14ebfecdf6ce19e15024103659f (patch)
treeda52c662b6253597bcaa9a0f5cfa5f2d75c0164d
parent53b513331add89e83c1327579f3da91ebbe97570 (diff)
downloadbusybox-4d8e5fdc1d4bb14ebfecdf6ce19e15024103659f.tar.gz
busybox-4d8e5fdc1d4bb14ebfecdf6ce19e15024103659f.tar.bz2
hush: optional support for ${var:N:M} bashism
function old new delta expand_vars_to_list 1999 2183 +184 handle_dollar 682 623 -59 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--shell/hush.c84
-rw-r--r--shell/hush_test/hush-vars/param_expand_bash_substring.right29
-rwxr-xr-xshell/hush_test/hush-vars/param_expand_bash_substring.tests46
3 files changed, 120 insertions, 39 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 06e9af2..0333395 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -46,7 +46,6 @@
* brace expansion: one/{two,three,four}
* reserved words: function select
* advanced test: [[ ]]
- * substrings: ${var:1:5}
* process substitution: <(list) and >(list)
* =~: regex operator
* let EXPR [EXPR...]
@@ -2586,7 +2585,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
var++;
} else {
/* maybe handle parameter expansion */
- exp_saveptr = var + strcspn(var, ":-=+?%#");
+ exp_saveptr = var + strcspn(var, "%#:-=+?");
exp_save = *exp_saveptr;
if (exp_save) {
exp_word = exp_saveptr;
@@ -2636,9 +2635,38 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
else if (loc) /* % or %% and match was found */
*loc = '\0';
}
- } else { /* one of :-=+? */
-//TODO: check validity of exp_op. Currently it can be anything.
-//TODO: handle ${VAR:N[:M]} here. N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
+ } else if (!strchr("%#:-=+?"+3, exp_op)) {
+#if ENABLE_HUSH_BASH_COMPAT
+ /* exp_op is ':' and next char isn't a subst operator.
+ * Assuming it's ${var:[N][:M]} bashism.
+ * TODO: N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
+ */
+ char *end;
+ unsigned len = INT_MAX;
+ unsigned beg = 0;
+ end = --exp_word;
+ if (*exp_word != ':') /* not ${var::...} */
+ beg = bb_strtou(exp_word, &end, 0);
+ //bb_error_msg("beg:'%s'=%u end:'%s'", exp_word, beg, end);
+ if (*end == ':') {
+ len = bb_strtou(end + 1, &end, 0);
+ //bb_error_msg("len:%u end:'%s'", len, end);
+ }
+ if (*end == '\0'
+ && end != exp_word /* not "${var:}" */
+ ) {
+ //bb_error_msg("from val:'%s'", val);
+ if (!val || beg >= strlen(val))
+ val = "";
+ else
+ val = dyn_val = xstrndup(val + beg, len);
+ //bb_error_msg("val:'%s'", val);
+ } else
+#endif
+ {
+ die_if_script("malformed ${%s...}", var);
+ }
+ } else { /* one of "-=+?" */
/* Standard-mandated substitution ops:
* ${var?word} - indicate error if unset
* If var is unset, word (or a message indicating it is unset
@@ -2693,7 +2721,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
}
*exp_saveptr = exp_save;
- }
+ } /* if (exp_op) */
arg[0] = first_ch;
#if ENABLE_HUSH_TICK
@@ -5926,14 +5954,15 @@ static int handle_dollar(o_string *as_string,
goto make_one_char_var;
case '{': {
bool first_char, all_digits;
- int expansion;
+ bool in_expansion_param;
ch = i_getch(input);
nommu_addchr(as_string, ch);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
- /* TODO: maybe someone will try to escape the '}' */
- expansion = 0;
+// TODO: need to handle "a=ab}; echo ${a%\}}"
+// and "a=abc; c=c; echo ${a%${c}}"
+ in_expansion_param = false;
first_char = true;
all_digits = false;
while (1) {
@@ -5957,45 +5986,22 @@ static int handle_dollar(o_string *as_string,
goto char_ok;
}
- if (expansion < 2
- && ( (all_digits && !isdigit(ch))
- || (!all_digits && !isalnum(ch) && ch != '_')
+ if (!in_expansion_param
+ && ( (all_digits && !isdigit(ch)) /* met non-digit: 123w */
+ || (!all_digits && !isalnum(ch) && ch != '_') /* met non-name char: abc% */
)
) {
/* handle parameter expansions
* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
*/
- if (first_char)
- goto case_default;
- switch (ch) {
- case ':': /* null modifier */
- if (expansion == 0) {
- debug_printf_parse(": null modifier\n");
- ++expansion;
- break;
- }
- goto case_default;
- case '#': /* remove prefix */
- case '%': /* remove suffix */
- if (expansion == 0) {
- debug_printf_parse(": remove suffix/prefix\n");
- expansion = 2;
- break;
- }
- goto case_default;
- case '-': /* default value */
- case '=': /* assign default */
- case '+': /* alternative */
- case '?': /* error indicate */
- debug_printf_parse(": parameter expansion\n");
- expansion = 2;
- break;
- default:
- case_default:
+ if (first_char /* bad (empty var name): "${%..." */
+ || !strchr("%#:-=+?", ch) /* bad: "${var<bad_char>..." */
+ ) {
syntax_error_unterm_str("${name}");
debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
return 1;
}
+ in_expansion_param = true;
}
char_ok:
debug_printf_parse(": '%c'\n", ch);
diff --git a/shell/hush_test/hush-vars/param_expand_bash_substring.right b/shell/hush_test/hush-vars/param_expand_bash_substring.right
new file mode 100644
index 0000000..9cd4659
--- /dev/null
+++ b/shell/hush_test/hush-vars/param_expand_bash_substring.right
@@ -0,0 +1,29 @@
+hush: syntax error: unterminated ${name}
+hush: syntax error: unterminated ${name}
+hush: syntax error: unterminated ${name}
+hush: syntax error: unterminated ${name}
+0123456789
+1 =||
+1:1 =||
+1:1:2=||
+1::2 =||
+1 =|0123|
+1:1 =|123|
+1:1:2=|12|
+1::2 =|01|
+f =||
+f:1 =||
+f:1:2=||
+f::2 =||
+f =||
+f:1 =||
+f:1:2=||
+f::2 =||
+f =|a|
+f:1 =||
+f:1:2=||
+f::2 =|a|
+f =|0123456789|
+f:1 =|123456789|
+f:1:2=|12|
+f::2 =|01|
diff --git a/shell/hush_test/hush-vars/param_expand_bash_substring.tests b/shell/hush_test/hush-vars/param_expand_bash_substring.tests
new file mode 100755
index 0000000..6a17655
--- /dev/null
+++ b/shell/hush_test/hush-vars/param_expand_bash_substring.tests
@@ -0,0 +1,46 @@
+# do all of these in subshells since it's supposed to error out
+
+export var=0123456789
+
+# first try some invalid patterns
+"$THIS_SH" -c 'echo ${:}'
+"$THIS_SH" -c 'echo ${::}'
+"$THIS_SH" -c 'echo ${:1}'
+"$THIS_SH" -c 'echo ${::1}'
+
+#this also is not valid in bash, but we accept it:
+"$THIS_SH" -c 'echo ${var:}'
+
+# then some funky ones
+# UNFIXED BUG: this should work: "$THIS_SH" -c 'echo ${?:0}'
+
+# now some valid ones
+"$THIS_SH" -c 'set --; echo "1 =|${1}|"'
+"$THIS_SH" -c 'set --; echo "1:1 =|${1:1}|"'
+"$THIS_SH" -c 'set --; echo "1:1:2=|${1:1:2}|"'
+"$THIS_SH" -c 'set --; echo "1::2 =|${1::2}|"'
+
+"$THIS_SH" -c 'set -- 0123; echo "1 =|${1}|"'
+"$THIS_SH" -c 'set -- 0123; echo "1:1 =|${1:1}|"'
+"$THIS_SH" -c 'set -- 0123; echo "1:1:2=|${1:1:2}|"'
+"$THIS_SH" -c 'set -- 0123; echo "1::2 =|${1::2}|"'
+
+"$THIS_SH" -c 'unset f; echo "f =|$f|"'
+"$THIS_SH" -c 'unset f; echo "f:1 =|${f:1}|"'
+"$THIS_SH" -c 'unset f; echo "f:1:2=|${f:1:2}|"'
+"$THIS_SH" -c 'unset f; echo "f::2 =|${f::2}|"'
+
+"$THIS_SH" -c 'f=; echo "f =|$f|"'
+"$THIS_SH" -c 'f=; echo "f:1 =|${f:1}|"'
+"$THIS_SH" -c 'f=; echo "f:1:2=|${f:1:2}|"'
+"$THIS_SH" -c 'f=; echo "f::2 =|${f::2}|"'
+
+"$THIS_SH" -c 'f=a; echo "f =|$f|"'
+"$THIS_SH" -c 'f=a; echo "f:1 =|${f:1}|"'
+"$THIS_SH" -c 'f=a; echo "f:1:2=|${f:1:2}|"'
+"$THIS_SH" -c 'f=a; echo "f::2 =|${f::2}|"'
+
+"$THIS_SH" -c 'f=0123456789; echo "f =|$f|"'
+"$THIS_SH" -c 'f=0123456789; echo "f:1 =|${f:1}|"'
+"$THIS_SH" -c 'f=0123456789; echo "f:1:2=|${f:1:2}|"'
+"$THIS_SH" -c 'f=0123456789; echo "f::2 =|${f::2}|"'