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-rw-r--r-- | ctdb/common/cmdline.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/ctdb/common/cmdline.h b/ctdb/common/cmdline.h new file mode 100644 index 0000000..51519ca --- /dev/null +++ b/ctdb/common/cmdline.h @@ -0,0 +1,163 @@ +/* + Command line processing + + Copyright (C) Amitay Isaacs 2018 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef __CTDB_CMDLINE_H__ +#define __CTDB_CMDLINE_H__ + +#include <popt.h> +#include <talloc.h> + +/** + * @file cmdline.h + * + * @brief Command-line handling with options and commands + * + * This abstraction encapsulates the boiler-plate for parsing options, + * commands and arguments on command-line. + * + * Options handling is done using popt. + */ + +/** + * @brief Abstract data structure holding command-line configuration + */ +struct cmdline_context; + +/** + * @brief A command definition structure + * + * @name is the name of the command + * @fn is the implementation of the command + * @msg_help is the help message describing command + * @msg_args is the help message describing arguments + * + * A command name can be a single word or multiple words separated with spaces. + * + * An implementation function should return 0 on success and non-zero value + * on failure. This value is returned as result in @cmdline_run. + */ +struct cmdline_command { + const char *name; + int (*fn)(TALLOC_CTX *mem_ctx, + int argc, + const char **argv, + void *private_data); + const char *msg_help; + const char *msg_args; +}; + +/** + * @brief convenience macro to define the end of commands list + * + * Here is an example of defining commands list. + * + * struct cmdline_command commands[] = { + * { "command1", command1_func, "Run command1", NULL }, + * { "command2", command2_func, "Run command2", "<filename>" }, + * CMDLINE_TABLEEND + * }; + */ +#define CMDLINE_TABLEEND { NULL, NULL, NULL, NULL } + +/** + * @brief Initialize cmdline abstraction + * + * If there are no options, options can be NULL. + * + * Help options (--help, -h) are automatically added to the options. + * + * @param[in] mem_ctx Talloc memory context + * @param[in] prog Program name + * @param[in] options Command-line options + * @param[in] section Name of section grouping specified commands + * @param[in] commands Commands array + * @param[out] result New cmdline context + * @return 0 on success, errno on failure + * + * Freeing cmdline context will free up all the resources. + */ +int cmdline_init(TALLOC_CTX *mem_ctx, + const char *prog, + struct poptOption *options, + const char *section, + struct cmdline_command *commands, + struct cmdline_context **result); + + +/** + * @brief Add command line section/commands + * + * @param[in] cmdline Cmdline context + * @param[in] section Name of section grouping specified commands + * @param[in] commands Commands array + * @return 0 on success, errno on failure + */ +int cmdline_add(struct cmdline_context *cmdline, + const char *section, + struct cmdline_command *commands); + +/** + * @brief Parse command line options and commands/arguments + * + * This function parses the arguments to process options and commands. + * + * This function should be passed the arguments to main() and parse_options + * should be set to true. If cmdline is used for handling second-level + * commands, then parse_options should be set to false. + * + * If argv does not match any command, then ENOENT is returned. + * + * @param[in] cmdline Cmdline context + * @param[in] argc Number of arguments + * @param[in] argv Arguments array + * @param[in] parse_options Whether to parse for options + * @return 0 on success, errno on failure + */ +int cmdline_parse(struct cmdline_context *cmdline, + int argc, + const char **argv, + bool parse_options); + +/** + * @brief Execute the function for the command matched by @cmdline_parse + * + * @param[in] cmdline Cmdline context + * @param[in] private_data Private data for implementation function + * @param[out] result Return value from the implementation function + * @return 0 on success, errno on failure + * + * If help options are specified, then detailed help will be printed and + * the return value will be EAGAIN. + */ +int cmdline_run(struct cmdline_context *cmdline, + void *private_data, + int *result); + +/** + * @brief Print usage help message to stdout + * + * @param[in] cmdline Cmdline context + * @param[in] command Command string + * + * If command is NULL, then full help is printed. + * If command is specified, then compact help is printed. + */ +void cmdline_usage(struct cmdline_context *cmdline, const char *command); + +#endif /* __CTDB_CMDLINE_H__ */ |