* Here Documents ( << word )
* Functions
* Tilde Expansion
- * fancy forms of Parameter Expansion: ${var:-val}
+ * Parameter Expansion for substring processing ${var#word} ${var%word}
*
* Bash stuff maybe optional enable:
* &> and >& redirection of stdout+stderr
* Brace expansion
* reserved words: [[ ]] function select
+ * substrings ${var:1:5}
*
* Major bugs:
* job handling woefully incomplete and buggy (improved --vda)
#if 1
/* Normal */
-static void syntax(const char *msg)
+static void maybe_die(const char *notice, const char *msg)
{
-#if ENABLE_HUSH_INTERACTIVE
/* Was using fancy stuff:
* (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
* but it SEGVs. ?! Oh well... explicit temp ptr works around that */
- void FAST_FUNC (*fp)(const char *s, ...);
+ void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
+#if ENABLE_HUSH_INTERACTIVE
fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
- fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
-#else
- bb_error_msg_and_die(msg ? "%s: %s" : "syntax error", "syntax error", msg);
#endif
+ fp(msg ? "%s: %s" : notice, notice, msg);
+}
+static void syntax(const char *msg)
+{
+ maybe_die("syntax error", msg);
}
#else
/* Debug */
}
/* str holds "NAME=VAL" and is expected to be malloced.
- * We take ownership of it. */
+ * We take ownership of it.
+ * flg_export is used by:
+ * 0: do not export
+ * 1: export
+ * -1: if NAME is set, leave export status alone
+ * if NAME is not set, do not export
+ */
static int set_local_var(char *str, int flg_export)
{
struct variable *cur;
set_str_and_exp:
cur->varstr = str;
exp:
- if (flg_export)
+ if (flg_export == 1)
cur->flg_export = 1;
if (cur->flg_export) {
debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
val = utoa(G.last_return_code);
break;
case '#': /* argc */
+ if (arg[1] != SPECIAL_VAR_SYMBOL)
+ /* actually, it's a ${#var} */
+ goto case_default;
val = utoa(G.global_argc ? G.global_argc-1 : 0);
break;
case '*':
}
#endif
default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
+ case_default: {
+ bool exp_len = false, exp_null = false;
+ char *var = arg, exp_save, exp_op, *exp_word;
+ size_t exp_off = 0;
*p = '\0';
arg[0] = first_ch & 0x7f;
- if (isdigit(arg[0])) {
- i = xatoi_u(arg);
+
+ /* prepare for expansions */
+ if (var[0] == '#') {
+ /* handle length expansion ${#var} */
+ exp_len = true;
+ ++var;
+ } else {
+ /* maybe handle parameter expansion */
+ exp_off = strcspn(var, ":-=+?");
+ if (!var[exp_off])
+ exp_off = 0;
+ if (exp_off) {
+ exp_save = var[exp_off];
+ exp_null = exp_save == ':';
+ exp_word = var + exp_off;
+ if (exp_null) ++exp_word;
+ exp_op = *exp_word++;
+ var[exp_off] = '\0';
+ }
+ }
+
+ /* lookup the variable in question */
+ if (isdigit(var[0])) {
+ i = xatoi_u(var);
if (i < G.global_argc)
val = G.global_argv[i];
/* else val remains NULL: $N with too big N */
} else
- val = lookup_param(arg);
+ val = lookup_param(var);
+
+ /* handle any expansions */
+ if (exp_len) {
+ debug_printf_expand("expand: length of '%s' = ", val);
+ 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");
+ 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);
+ }
+ }
+ }
+ var[exp_off] = exp_save;
+ }
+
arg[0] = first_ch;
+
#if ENABLE_HUSH_TICK
store_val:
#endif
- *p = SPECIAL_VAR_SYMBOL;
if (!(first_ch & 0x80)) { /* unquoted $VAR */
debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
if (val) {
debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
}
}
+ }
if (val) {
o_addQstr(output, val, strlen(val));
}
+ /* Do the check to avoid writing to a const string */
+ if (p && *p != SPECIAL_VAR_SYMBOL)
+ *p = SPECIAL_VAR_SYMBOL;
#if ENABLE_HUSH_TICK
o_free(&subst_result);
/* Return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct in_str *input)
{
+ int expansion;
int ch = i_peek(input); /* first character after the $ */
unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
case '*': /* args */
case '@': /* args */
goto make_one_char_var;
- case '{':
+ case '{': {
+ bool first_char;
+
o_addchr(dest, SPECIAL_VAR_SYMBOL);
i_getch(input);
/* XXX maybe someone will try to escape the '}' */
+ expansion = 0;
+ first_char = true;
while (1) {
ch = i_getch(input);
if (ch == '}')
break;
- if (!isalnum(ch) && ch != '_') {
- syntax("unterminated ${name}");
- debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
- return 1;
+
+ if (ch == '#' && first_char)
+ /* ${#var}: length of var contents */;
+
+ else if (expansion < 2 && !isalnum(ch) && ch != '_') {
+ /* 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;
+
+#if 0 /* not implemented yet :( */
+ case '#': /* remove prefix */
+ case '%': /* remove suffix */
+ if (expansion == 0) {
+ debug_printf_parse(": remove suffix/prefix\n");
+ expansion = 2;
+ break;
+ }
+ goto case_default;
+#endif
+
+ case '-': /* default value */
+ case '=': /* assign default */
+ case '+': /* alternative */
+ case '?': /* error indicate */
+ debug_printf_parse(": parameter expansion\n");
+ expansion = 2;
+ break;
+
+ default:
+ case_default:
+ syntax("unterminated ${name}");
+ debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
+ return 1;
+ }
}
debug_printf_parse(": '%c'\n", ch);
o_addchr(dest, ch | quote_mask);
quote_mask = 0;
+ first_char = false;
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
+ }
#if ENABLE_HUSH_TICK
case '(': {
//int pos = dest->length;
projects / oweals / busybox.git / commitdiff