[RFC/PATCH] parse-options: introduce parse_subcommands
- From
Ramkumar Ramachandra <artagnon@gmail.com>
- Date
- Jun 4, 2012, 09:35 UTC
- Message-ID
- <1338802534-32394-1-git-send-email-artagnon@gmail.com>
Some git builtins like git-notes use subcommands to switch between different modes of operation. Introduce a parse_subcommands similar to parse_options to aid parsing these options. The main advantage of using it is that subcommands can have a descriptive help text attached to them.
Make the git-notes builtin use parse_subcommands. As a result, the following error:
$ git notes foo
error: Unknown subcommand: foo
usage: git notes [--ref <notes_ref>] [list [<object>]]
or: git notes [--ref <notes_ref>] add [-f] [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]
or: git notes [--ref <notes_ref>] copy [-f] <from-object> <to-object>
or: git notes [--ref <notes_ref>] append [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]
or: git notes [--ref <notes_ref>] edit [<object>]
or: git notes [--ref <notes_ref>] show [<object>]
or: git notes [--ref <notes_ref>] merge [-v | -q] [-s <strategy> ] <notes_ref>
or: git notes merge --commit [-v | -q]
or: git notes merge --abort [-v | -q]
or: git notes [--ref <notes_ref>] remove [<object>...]
or: git notes [--ref <notes_ref>] prune [-n | -v]
or: git notes [--ref <notes_ref>] get-ref--ref <notes_ref> use notes from <notes_ref>
is replaced by a more helpful:
$ git notes foo error: unknown subcommand: foo usage: git notes [<options>] [<subcommand>] [<options>] [<object>..]
available subcommands:
list list notes for given object
add add notes for given object
copy copy notes for first object onto second object
append append notes to existing object
edit edit notes for given object
show show notes for given object
merge merge given notes ref into current notes ref
remove remove notes for given objects
prune remove all notes for non-existing/unreachable objects
get-ref print the current notes refSigned-off-by: Ramkumar Ramachandra <artagnon@gmail.com> --- I found this patch in one of my branches from a long time ago. I haven't written documentation and tests yet because I'm not fully convinced that I like this.
Thoughts?
builtin/notes.c | 56 ++++++++++++++++++++++--------------------------------- parse-options.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++ parse-options.h | 10 ++++++++++ 3 files changed, 79 insertions(+), 34 deletions(-)
diff --git a/builtin/notes.c b/builtin/notes.c index 3644d14..b1d6206 100644 --- a/builtin/notes.c +++ b/builtin/notes.c @@ -20,18 +20,7 @@ #include "notes-merge.h" static const char * const git_notes_usage[] = { - "git notes [--ref <notes_ref>] [list [<object>]]", - "git notes [--ref <notes_ref>] add [-f] [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]", - "git notes [--ref <notes_ref>] copy [-f] <from-object> <to-object>", - "git notes [--ref <notes_ref>] append [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]", - "git notes [--ref <notes_ref>] edit [<object>]", - "git notes [--ref <notes_ref>] show [<object>]", - "git notes [--ref <notes_ref>] merge [-v | -q] [-s <strategy> ] <notes_ref>", - "git notes merge --commit [-v | -q]", - "git notes merge --abort [-v | -q]", - "git notes [--ref <notes_ref>] remove [<object>...]", - "git notes [--ref <notes_ref>] prune [-n | -v]", - "git notes [--ref <notes_ref>] get-ref", + "git notes [<options>] [<subcommand>] [<options>] [<object>..]", NULL }; @@ -1081,28 +1070,27 @@ int cmd_notes(int argc, const char **argv, const char *prefix) strbuf_release(&sb); } - if (argc < 1 || !strcmp(argv[0], "list")) - result = list(argc, argv, prefix); - else if (!strcmp(argv[0], "add")) - result = add(argc, argv, prefix); - else if (!strcmp(argv[0], "copy")) - result = copy(argc, argv, prefix); - else if (!strcmp(argv[0], "append") || !strcmp(argv[0], "edit")) - result = append_edit(argc, argv, prefix); - else if (!strcmp(argv[0], "show")) - result = show(argc, argv, prefix); - else if (!strcmp(argv[0], "merge")) - result = merge(argc, argv, prefix); - else if (!strcmp(argv[0], "remove")) - result = remove_cmd(argc, argv, prefix); - else if (!strcmp(argv[0], "prune")) - result = prune(argc, argv, prefix); - else if (!strcmp(argv[0], "get-ref")) - result = get_ref(argc, argv, prefix); - else { - result = error(_("Unknown subcommand: %s"), argv[0]); - usage_with_options(git_notes_usage, options); - } + struct subcommand subcmds[] = { + { "list", "list notes for given object", list }, + { "add", "add notes for given object", add }, + { "copy", + "copy notes for first object onto second object", copy }, + { "append", "append notes to existing object", append_edit }, + { "edit", "edit notes for given object", append_edit }, + { "show", "show notes for given object", show }, + { "merge", + "merge given notes ref into current notes ref", merge }, + { "remove", "remove notes for given objects", remove_cmd }, + { "prune", + "remove all notes for non-existing/unreachable objects", prune }, + { "get-ref", "print the current notes ref", get_ref }, + { NULL } + }; + if (argc < 1) + result = list(argc, argv, prefix); + else + result = parse_subcommands(argc, argv, prefix, + subcmds, git_notes_usage); return result ? 1 : 0; } diff --git a/parse-options.c b/parse-options.c index f0098eb..76640fb 100644 --- a/parse-options.c +++ b/parse-options.c @@ -583,3 +583,50 @@ static int parse_options_usage(struct parse_opt_ctx_t *ctx, return usage_with_options_internal(ctx, usagestr, opts, 0, err); } +static void subcommand_usage(const char * const *usagestr, + const struct subcommand *subcmds) +{ + const struct subcommand *subcmd; + + fprintf(stderr, "usage: %s\n", *usagestr++); + while (*usagestr && **usagestr) + fprintf(stderr, " or: %s\n", *usagestr++); + while (*usagestr) { + fprintf(stderr, "%s%s\n", + **usagestr ? " " : "", + *usagestr); + usagestr++; + } + + fputc('\n', stderr); + fprintf(stderr, "available subcommands:\n"); + for (subcmd = subcmds; subcmd->name != NULL; subcmd ++) { + size_t pos; + int pad; + + pos = fprintf(stderr, " "); + pos += fprintf(stderr, "%s", subcmd->name); + + if (pos <= USAGE_OPTS_WIDTH) + pad = USAGE_OPTS_WIDTH - pos; + else { + fputc('\n', stderr); + pad = USAGE_OPTS_WIDTH; + } + fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", subcmd->help); + } + fputc('\n', stderr); +} + +int parse_subcommands(int argc, const char **argv, const char *prefix, + const struct subcommand *subcmds, const char * const usagestr[]) +{ + const struct subcommand *subcmd; + + for (subcmd = subcmds; subcmd->name != NULL; subcmd ++) + if (!strcmp(subcmd->name, argv[0])) + return (*subcmd->callback)(argc, argv, prefix); + error("unknown subcommand: %s", argv[0]); + subcommand_usage(usagestr, subcmds); + exit(129); +} diff --git a/parse-options.h b/parse-options.h index 2e811dc..e95ad10 100644 --- a/parse-options.h +++ b/parse-options.h @@ -46,6 +46,7 @@ enum parse_opt_option_flags { struct option; typedef int parse_opt_cb(const struct option *, const char *arg, int unset); +typedef int subcmd_cb(int argc, const char **argv, const char *prefix); struct parse_opt_ctx_t; typedef int parse_opt_ll_cb(struct parse_opt_ctx_t *ctx, @@ -117,6 +118,12 @@ struct option { intptr_t defval; }; +struct subcommand { + const char *name; + const char *help; + subcmd_cb *callback; +}; + #define OPT_END() { OPTION_END } #define OPT_ARGUMENT(l, h) { OPTION_ARGUMENT, 0, (l), NULL, NULL, \ (h), PARSE_OPT_NOARG} @@ -169,6 +176,9 @@ extern int parse_options(int argc, const char **argv, const char *prefix, const struct option *options, const char * const usagestr[], int flags); +extern int parse_subcommands(int argc, const char **argv, const char *prefix, + const struct subcommand *subcmds, const char * const usagestr[]); + extern NORETURN void usage_with_options(const char * const *usagestr, const struct option *options);
-- 1.7.10