* follow IFS rules more precisely, including update semantics
* builtins mandated by standards we don't support:
* [un]alias, command, fc, getopts, newgrp, readonly, times
+ * make complex ${var%...} constructs support optional
+ * make here documents optional
*
* Bash compat TODO:
* redirection of stdout+stderr: &> and >&
* echo $(echo 'TEST)' BEST) TEST) BEST
* echo $(echo \(\(TEST\) BEST) ((TEST) BEST
*
- * BUG: enter: echo $(( `printf '(\x28 1'` + `echo 2))` ))
- * on the command line, press Enter. You get > prompt which is impossible
- * to exit with ^C.
+ * Also adapted to eat ${var%...} constructs, since ... part
+ * can contain arbitrary constructs, just like $(cmd).
*/
#define DOUBLE_CLOSE_CHAR_FLAG 0x80
static void add_till_closing_paren(o_string *dest, struct in_str *input, char end_ch)
{
- int count = 0;
char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
end_ch &= (DOUBLE_CLOSE_CHAR_FLAG-1);
while (1) {
int ch = i_getch(input);
if (ch == EOF) {
- syntax_error_unterm_ch(')');
+ syntax_error_unterm_ch(end_ch);
/*xfunc_die(); - redundant */
}
- if (ch == '(' || ch == '{')
- count++;
- if (ch == ')' || ch == '}') {
- count--;
- if (count < 0 && ch == end_ch) {
- if (!dbl)
- break;
- if (i_peek(input) == ')') {
- i_getch(input);
- break;
- }
+ if (ch == end_ch) {
+ if (!dbl)
+ break;
+ /* we look for closing )) of $((EXPR)) */
+ if (i_peek(input) == end_ch) {
+ i_getch(input); /* eat second ')' */
+ break;
}
}
o_addchr(dest, ch);
+ if (ch == '(' || ch == '{') {
+ ch = (ch == '(' ? ')' : '}');
+ add_till_closing_paren(dest, input, ch);
+ o_addchr(dest, ch);
+ continue;
+ }
if (ch == '\'') {
add_till_single_quote(dest, input);
o_addchr(dest, ch);
o_addchr(dest, ch);
continue;
}
+ if (ch == '`') {
+ add_till_backquote(dest, input);
+ o_addchr(dest, ch);
+ continue;
+ }
if (ch == '\\') {
/* \x. Copy verbatim. Important for \(, \) */
ch = i_getch(input);
echo 29 $(( iv += (jv + 9)))
echo 5 $(( (iv + 4) % 7 ))
-# unary plus, minus
+echo unary plus, minus
echo -4 $(( +4 - 8 ))
echo 4 $(( -4 + 8 ))
-# conditional expressions
+echo conditional expressions
echo 1 $(( 4<5 ? 1 : 32))
echo 32 $(( 4>5 ? 1 : 32))
echo 32 $(( 4>(2+3) ? 1 : 32))
echo 1 $(( (2+2)<(2+3) ? 1 : 32))
echo 32 $(( (2+2)>(2+3) ? 1 : 32))
-# check that the unevaluated part of the ternary operator does not do
-# evaluation or assignment
+echo 'check that parentheses in `cmd` are interpreted correctly'
+# \x28 is '('
+echo 3 $(( ( `printf '(\x28 1'` + `echo 2\)\)` ) ))
+
+echo check that the unevaluated part of the ternary operator does not do evaluation or assignment
x=i+=2
y=j+=2
#ash# declare -i i=1 j=1
echo 30 $((0 ? (y+=2) : 30))
#ash# echo $i,$y # ash mishandles this
-# check precedence of assignment vs. conditional operator
+echo check precedence of assignment vs. conditional operator
# should be an error
#ash# declare -i x=2
x=2
#ashnote# bash reports error but continues, ash aborts - using subshell to 'emulate' bash:
( y=$((1 ? 20 : x+=2)) )
-# check precedence of assignment vs. conditional operator
+echo check precedence of assignment vs. conditional operator
#ash# declare -i x=2
x=2
# ash says "line NNN: syntax error: 0 ? x+=2 : 20"
#ash# echo 20 $((0 ? x+=2 : 20))
-# associativity of assignment-operator operator
+echo associativity of assignment-operator operator
#ash# declare -i i=1 j=2 k=3
i=1
j=2
echo 6 $((i += j += k))
echo 6,5,3 $i,$j,$k
-# octal, hex
+echo octal, hex
echo 263 $(( 0x100 | 007 ))
echo 255 $(( 0xff ))
#ash# echo 255 $(( 16#ff ))