Re: [PATCH 2/2] commands: test: add based support for bash-test style

[Sascha Hauer <sha@pengutronix.de>]

On Tue, Jul 04, 2023 at 12:58:13AM +0200, Marco Felsch wrote:
> Add [[ expression ]] support which allow pattern matching like:
> 
>   - [[ "foo1" == "foo*" ]]

It's a bit unfortunate that in barebox we require putting the pattern in
"", whereas in bash it only works without the "".

I guess there's not much we can do about this unless we turn the '['
command into a shell builtin.

>   - [[ "foo" != "bar" ]]
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  commands/Kconfig | 13 +++++++++++++
>  commands/test.c  | 39 ++++++++++++++++++++++++++++++++++-----
>  2 files changed, 47 insertions(+), 5 deletions(-)
> 
> diff --git a/commands/Kconfig b/commands/Kconfig
> index 4d3ff631a8..615e96aa9d 100644
> --- a/commands/Kconfig
> +++ b/commands/Kconfig
> @@ -1219,6 +1219,19 @@ config CMD_TEST
>  		  !, =, !=, -eq, -ne, -ge, -gt, -le, -lt, -o, -a, -z, -n, -d, -e,
>  		  -f, -L; see 'man test' on your PC for more information.
>  
> +if CMD_TEST
> +
> +config CMD_TEST_BASH_COMP
> +	tristate
> +	select CONFIG_FNMATCH
> +	prompt "test bash-compatibility"
> +	help
> +	  Enable minimal support for bash compatible tests: [[ ]] to allow
> +	  pattern matching via: == and !=
> +
> +# end CMD_TEST
> +endif
> +
>  config CMD_TRUE
>  	tristate
>  	default y
> diff --git a/commands/test.c b/commands/test.c
> index c1b84c42ef..77e15aeb03 100644
> --- a/commands/test.c
> +++ b/commands/test.c
> @@ -11,9 +11,13 @@
>  #include <command.h>
>  #include <fs.h>
>  #include <linux/stat.h>
> +#ifdef CONFIG_CMD_TEST_BASH_COMP
> +#include <fnmatch.h>
> +#endif

No need to include this conditionally.

>  
>  typedef enum {
>  	OPT_EQUAL,
> +	OPT_EQUAL_BASH,
>  	OPT_NOT_EQUAL,
>  	OPT_ARITH_EQUAL,
>  	OPT_ARITH_NOT_EQUAL,
> @@ -36,6 +40,7 @@ typedef enum {
>  
>  static char *test_options[] = {
>  	[OPT_EQUAL]			= "=",
> +	[OPT_EQUAL_BASH]		= "==",
>  	[OPT_NOT_EQUAL]			= "!=",
>  	[OPT_ARITH_EQUAL]		= "-eq",
>  	[OPT_ARITH_NOT_EQUAL]		= "-ne",
> @@ -67,18 +72,37 @@ static int parse_opt(const char *opt)
>  	return -1;
>  }
>  
> +static int string_comp(const char *left_op, const char *right_op, bool bash_test)
> +{
> +#ifdef CONFIG_CMD_TEST_BASH_COMP
> +	if (bash_test)
> +		return fnmatch(right_op, left_op, 0);
> +#endif
> +	return strcmp(left_op, right_op);
> +}
> +
>  static int do_test(int argc, char *argv[])
>  {
>  	char **ap;
>  	int left, adv, expr, last_expr, neg, last_cmp, opt, zero;
>  	ulong a, b;
>  	struct stat statbuf;
> +	bool bash_test = false;
>  
>  	if (*argv[0] == '[') {
>  		argc--;
> -		if (*argv[argc] != ']') {
> -			printf("[: missing `]'\n");
> -			return 1;
> +		if (!strncmp(argv[0], "[[", 2)) {
> +			if (strncmp(argv[argc], "]]", 2) != 0) {
> +				printf("[[: missing `]]'\n");
> +				return 1;
> +			}
> +			if (IS_ENABLED(CONFIG_CMD_TEST_BASH_COMP))
> +				bash_test = true;

The if() is unnecessary.

Sascha

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