xz: Add a new --filters-help option.

The --filters-help can be used to help create filter chains with the
--filters and --filtersX options. The message in --long-help is too
short to fully explain the syntax to construct complex filter chains.

In --robot mode, xz will only print the output from liblzma function
lzma_str_list_filters.
This commit is contained in:
Jia Tan 2023-05-13 00:44:41 +08:00
parent 95f1a414b1
commit a165d7df19
3 changed files with 43 additions and 0 deletions

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@ -180,6 +180,7 @@ parse_real(args_info *args, int argc, char **argv)
OPT_FILTERS7, OPT_FILTERS7,
OPT_FILTERS8, OPT_FILTERS8,
OPT_FILTERS9, OPT_FILTERS9,
OPT_FILTERS_HELP,
OPT_X86, OPT_X86,
OPT_POWERPC, OPT_POWERPC,
@ -261,6 +262,7 @@ parse_real(args_info *args, int argc, char **argv)
{ "filters7", optional_argument, NULL, OPT_FILTERS7}, { "filters7", optional_argument, NULL, OPT_FILTERS7},
{ "filters8", optional_argument, NULL, OPT_FILTERS8}, { "filters8", optional_argument, NULL, OPT_FILTERS8},
{ "filters9", optional_argument, NULL, OPT_FILTERS9}, { "filters9", optional_argument, NULL, OPT_FILTERS9},
{ "filters-help", optional_argument, NULL, OPT_FILTERS_HELP},
{ "lzma1", optional_argument, NULL, OPT_LZMA1 }, { "lzma1", optional_argument, NULL, OPT_LZMA1 },
{ "lzma2", optional_argument, NULL, OPT_LZMA2 }, { "lzma2", optional_argument, NULL, OPT_LZMA2 },
@ -447,6 +449,12 @@ parse_real(args_info *args, int argc, char **argv)
(size_t)(c - OPT_FILTERS)); (size_t)(c - OPT_FILTERS));
break; break;
// --filters-help
case OPT_FILTERS_HELP:
// This doesn't return.
message_filters_help();
break;
case OPT_X86: case OPT_X86:
coder_add_filter(LZMA_FILTER_X86, coder_add_filter(LZMA_FILTER_X86,
options_bcj(optarg)); options_bcj(optarg));

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@ -1071,6 +1071,11 @@ message_help(bool long_help)
" string syntax to use with --block-list" " string syntax to use with --block-list"
)); ));
puts(_(
" --filters-help display more information about the liblzma filter string\n"
" syntax and exit."
));
#if defined(HAVE_ENCODER_LZMA1) || defined(HAVE_DECODER_LZMA1) \ #if defined(HAVE_ENCODER_LZMA1) || defined(HAVE_DECODER_LZMA1) \
|| defined(HAVE_ENCODER_LZMA2) || defined(HAVE_DECODER_LZMA2) || defined(HAVE_ENCODER_LZMA2) || defined(HAVE_DECODER_LZMA2)
// TRANSLATORS: The word "literal" in "literal context bits" // TRANSLATORS: The word "literal" in "literal context bits"
@ -1158,3 +1163,28 @@ message_help(bool long_help)
tuklib_exit(E_SUCCESS, E_ERROR, verbosity != V_SILENT); tuklib_exit(E_SUCCESS, E_ERROR, verbosity != V_SILENT);
} }
extern void
message_filters_help(void)
{
char *encoder_options;
if (lzma_str_list_filters(&encoder_options, LZMA_VLI_UNKNOWN,
LZMA_STR_ENCODER, NULL) != LZMA_OK)
message_bug();
if (!opt_robot) {
puts(_(
"Filter chains are set using the --filters=FILTERS or\n"
"--filters1=FILTERS ... --filters9=FILTERS options. Each filter in the chain\n"
"can be separated by spaces or `--'. Alternatively a preset <0-9>[e] can be\n"
"specified instead of a filter chain.\n"
));
puts(_("The supported filters and their options are:"));
}
puts(encoder_options);
tuklib_exit(E_SUCCESS, E_ERROR, verbosity != V_SILENT);
}

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@ -107,6 +107,11 @@ extern void message_version(void) lzma_attribute((__noreturn__));
extern void message_help(bool long_help) lzma_attribute((__noreturn__)); extern void message_help(bool long_help) lzma_attribute((__noreturn__));
/// Prints a help message specifically for using the --filters and
/// --filtersX command line options.
extern void message_filters_help(void);
/// \brief Set the total number of files to be processed /// \brief Set the total number of files to be processed
/// ///
/// Standard input is counted as a file here. This is used when printing /// Standard input is counted as a file here. This is used when printing