In addition to "-ovalue" and "--opt=value" syntax, allow also "-o value" and "--opt value" for options with optional argument when the newly added PARSE_OPT_OPTARG_ALLOW_NEXT flag is set.
This behavior is turned off by default since it does not make sense for tools using non-option command line arguments. Consider the ambiguity of "cmd -d x", where "-d x" can mean either "-d with argument of x" or "-d without argument, followed by non-option argument x". This is not an issue in the case that the tool takes no non-option arguments. To implement this, a new local variable, force_defval, is created in get_value(), along with a comment explaining the logic. Signed-off-by: Tomas Glozar <[email protected]> --- tools/lib/subcmd/parse-options.c | 53 +++++++++++++++++++++++++++----- tools/lib/subcmd/parse-options.h | 1 + 2 files changed, 46 insertions(+), 8 deletions(-) diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c index 555d617c1f50..664b2053bb77 100644 --- a/tools/lib/subcmd/parse-options.c +++ b/tools/lib/subcmd/parse-options.c @@ -72,6 +72,7 @@ static int get_value(struct parse_opt_ctx_t *p, const char *s, *arg = NULL; const int unset = flags & OPT_UNSET; int err; + bool force_defval = false; if (unset && p->opt) return opterror(opt, "takes no value", flags); @@ -123,6 +124,42 @@ static int get_value(struct parse_opt_ctx_t *p, } } + if (opt->flags & PARSE_OPT_OPTARG && !p->opt) { + if (!(p->flags & PARSE_OPT_OPTARG_ALLOW_NEXT)) { + /* + * If the option has an optional argument, and the argument is not + * provided in the option itself, do not attempt to get it from + * the next argument, unless PARSE_OPT_OPTARG_ALLOW_NEXT is set. + * + * This prevents a non-option argument from being interpreted as an + * optional argument of a preceding option, for example: + * + * $ cmd --opt val + * -> is "val" argument of "--opt" or a separate non-option + * argument? + * + * With PARSE_OPT_OPTARG_ALLOW_NEXT, "val" is interpreted as + * the argument of "--opt", i.e. the same as "--opt=val". + * Without PARSE_OPT_OPTARG_ALLOW_NEXT, --opt is interpreted + * as having the default value, and "val" as a separate non-option + * argument. + * + * PARSE_OPT_OPTARG_ALLOW_NEXT is useful for commands that take no + * non-option arguments and want to allow more flexibility in + * optional argument passing. + */ + force_defval = true; + } + + if (p->argc <= 1 || p->argv[1][0] == '-') { + /* + * If next argument is an option or does not exist, + * use the default value. + */ + force_defval = true; + } + } + if (opt->flags & PARSE_OPT_NOBUILD) { char reason[128]; bool noarg = false; @@ -148,7 +185,7 @@ static int get_value(struct parse_opt_ctx_t *p, noarg = true; if (opt->flags & PARSE_OPT_NOARG) noarg = true; - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) + if (force_defval) noarg = true; switch (opt->type) { @@ -212,7 +249,7 @@ static int get_value(struct parse_opt_ctx_t *p, err = 0; if (unset) *(const char **)opt->value = NULL; - else if (opt->flags & PARSE_OPT_OPTARG && !p->opt) + else if (force_defval) *(const char **)opt->value = (const char *)opt->defval; else err = get_arg(p, opt, flags, (const char **)opt->value); @@ -244,7 +281,7 @@ static int get_value(struct parse_opt_ctx_t *p, return (*opt->callback)(opt, NULL, 1) ? (-1) : 0; if (opt->flags & PARSE_OPT_NOARG) return (*opt->callback)(opt, NULL, 0) ? (-1) : 0; - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) + if (force_defval) return (*opt->callback)(opt, NULL, 0) ? (-1) : 0; if (get_arg(p, opt, flags, &arg)) return -1; @@ -255,7 +292,7 @@ static int get_value(struct parse_opt_ctx_t *p, *(int *)opt->value = 0; return 0; } - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) { + if (force_defval) { *(int *)opt->value = opt->defval; return 0; } @@ -271,7 +308,7 @@ static int get_value(struct parse_opt_ctx_t *p, *(unsigned int *)opt->value = 0; return 0; } - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) { + if (force_defval) { *(unsigned int *)opt->value = opt->defval; return 0; } @@ -289,7 +326,7 @@ static int get_value(struct parse_opt_ctx_t *p, *(long *)opt->value = 0; return 0; } - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) { + if (force_defval) { *(long *)opt->value = opt->defval; return 0; } @@ -305,7 +342,7 @@ static int get_value(struct parse_opt_ctx_t *p, *(unsigned long *)opt->value = 0; return 0; } - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) { + if (force_defval) { *(unsigned long *)opt->value = opt->defval; return 0; } @@ -321,7 +358,7 @@ static int get_value(struct parse_opt_ctx_t *p, *(u64 *)opt->value = 0; return 0; } - if (opt->flags & PARSE_OPT_OPTARG && !p->opt) { + if (force_defval) { *(u64 *)opt->value = opt->defval; return 0; } diff --git a/tools/lib/subcmd/parse-options.h b/tools/lib/subcmd/parse-options.h index 8e9147358a28..c573a0ca5ca6 100644 --- a/tools/lib/subcmd/parse-options.h +++ b/tools/lib/subcmd/parse-options.h @@ -33,6 +33,7 @@ enum parse_opt_flags { PARSE_OPT_KEEP_ARGV0 = 4, PARSE_OPT_KEEP_UNKNOWN = 8, PARSE_OPT_NO_INTERNAL_HELP = 16, + PARSE_OPT_OPTARG_ALLOW_NEXT = 32, }; enum parse_opt_option_flags { -- 2.53.0
