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hush: add HUSH_BASH_COMPAT, make [[ special handling depend on it

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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2009-06-10 13:39:35 +02:00
parent 1d77db8459
commit 9ca656b149
2 changed files with 40 additions and 29 deletions
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13
shell/Config.in
View File

@ -43,9 +43,6 @@ config ASH
shell (by Herbert Xu), which was created by porting the 'ash' shell
(written by Kenneth Almquist) from NetBSD.
comment "Ash Shell Options"
depends on ASH
config ASH_BASH_COMPAT
bool "bash-compatible extensions"
default y
@ -169,6 +166,13 @@ config HUSH
It does not handle select, aliases, brace expansion,
tilde expansion, &>file and >&file redirection of stdout+stderr.
config HUSH_BASH_COMPAT
bool "bash-compatible extensions"
default y
depends on HUSH
help
Enable bash-compatible extensions.
config HUSH_HELP
bool "help builtin"
default n
@ -268,9 +272,6 @@ config MSH
# It uses only vfork, so it can be used on uClinux systems.
comment "Bourne Shell Options"
depends on MSH || LASH || HUSH || ASH
config SH_MATH_SUPPORT
bool "POSIX math support"
default y

56
shell/hush.c
View File

@ -42,11 +42,18 @@
* <(list) and >(list) Process Substitution
* Tilde Expansion
*
* Bash stuff (maybe optionally enable?):
* Bash stuff (optionally enabled):
* &> and >& redirection of stdout+stderr
* Brace Expansion
* reserved words: [[ ]] function select
* substrings ${var:1:5}
* let EXPR [EXPR...]
* Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
* If the last arg evaluates to 0, let returns 1; 0 otherwise.
* NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
* ((EXPR))
* The EXPR is evaluated according to ARITHMETIC EVALUATION.
* This is exactly equivalent to let "expression".
*
* TODOs:
* grep for "TODO" and fix (some of them are easy)
@ -59,7 +66,7 @@
* $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
* ls: cannot access i=a: No such file or directory
* ls: cannot access b: No such file or directory
* Note1: same applies to local builtin when we'll have it.
* Note1: same applies to local builtin.
* Note2: bash 3.2.33(1) does this only if export word itself
* is not quoted:
* $ export i=`echo 'aaa bbb'`; echo "$i"
@ -299,28 +306,11 @@ struct command {
smallint cmd_type; /* CMD_xxx */
#define CMD_NORMAL 0
#define CMD_SUBSHELL 1
/* used for "[[ EXPR ]]" */
#define CMD_SINGLEWORD_NOGLOB 2
/* used for "export noglob=* glob* a=`echo a b`" */
/* #define CMD_SINGLEWORD_NOGLOB_COND 3 */
// It is hard to implement correctly, adds significant amounts of tricky code,
// and all this only useful for really obscure export statements
// almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
// guard the code which implement it, but I have doubts it works
// in all cases (especially with mixed globbed/non-globbed arguments)
#if ENABLE_HUSH_FUNCTIONS
# define CMD_FUNCDEF 4
#if ENABLE_HUSH_BASH_COMPAT
# define CMD_SINGLEWORD_NOGLOB 2
#endif
//TODO
//#define CMD_ARITH - let EXPR, ((EXPR))
//let EXPR [EXPR...]
// Each EXPR is an arithmetic expression to be evaluated (ARITHMETIC EVALUATION)
// If the last arg evaluates to 0, let returns 1; 0 is returned otherwise.
// NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
//((EXPR))
// The EXPR is evaluated according to ARITHMETIC EVALUATION.
// This is exactly equivalent to let "expression".
//[[ EXPR ]]
// Basically, word splitting and pathname expansion should NOT be performed
// Examples:
// no word splitting: a="a b"; [[ $a = "a b" ]]; echo $? should print "0"
@ -330,6 +320,18 @@ struct command {
// =~ regexp match
// Apart from the above, [[ expr ]] should work as [ expr ]
/* used for "export noglob=* glob* a=`echo a b`" */
/*#define CMD_SINGLEWORD_NOGLOB_COND 3 */
// It is hard to implement correctly, it adds significant amounts of tricky code,
// and all this is only useful for really obscure export statements
// almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
// guards the code which implements it, but I have doubts it works
// in all cases (especially with mixed globbed/non-globbed arguments)
#if ENABLE_HUSH_FUNCTIONS
# define CMD_FUNCDEF 3
#endif
/* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
struct pipe *group;
#if !BB_MMU
@ -2484,10 +2486,12 @@ static char **expand_strvec_to_strvec(char **argv)
return expand_variables(argv, 0x100);
}
#if ENABLE_HUSH_BASH_COMPAT
static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
{
return expand_variables(argv, 0x80);
}
#endif
#ifdef CMD_SINGLEWORD_NOGLOB_COND
static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
@ -3838,9 +3842,12 @@ static int run_pipe(struct pipe *pi)
}
/* Expand the rest into (possibly) many strings each */
if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
if (0) {}
#if ENABLE_HUSH_BASH_COMPAT
else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
}
#endif
#ifdef CMD_SINGLEWORD_NOGLOB_COND
else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
@ -4094,6 +4101,7 @@ static void debug_print_tree(struct pipe *pi, int lvl)
static const char *const CMDTYPE[] = {
"{}",
"()",
"[noglob]",
#if ENABLE_HUSH_FUNCTIONS
"func()",
#endif
@ -4833,10 +4841,12 @@ static int done_word(o_string *word, struct parse_context *ctx)
command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
} else
# endif
# if ENABLE_HUSH_BASH_COMPAT
if (strcmp(word->data, "[[") == 0) {
command->cmd_type = CMD_SINGLEWORD_NOGLOB;
}
/* fall through */
# endif
}
#endif
if (command->group) {