include/grpc/support/cmdline.h

/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#ifndef GRPC_SUPPORT_CMDLINE_H
#define GRPC_SUPPORT_CMDLINE_H

#include <grpc/support/port_platform.h>

#ifdef __cplusplus
extern "C" {
#endif

/** Simple command line parser.

   Supports flags that can be specified as -foo, --foo, --no-foo, -no-foo, etc
   And integers, strings that can be specified as -foo=4, -foo blah, etc

   No support for short command line options (but we may get that in the
   future.)

   Usage (for a program with a single flag argument 'foo'):

   int main(int argc, char **argv) {
     gpr_cmdline *cl;
     int verbose = 0;

     cl = gpr_cmdline_create("My cool tool");
     gpr_cmdline_add_int(cl, "verbose", "Produce verbose output?", &verbose);
     gpr_cmdline_parse(cl, argc, argv);
     gpr_cmdline_destroy(cl);

     if (verbose) {
       gpr_log(GPR_INFO, "Goodbye cruel world!");
     }

     return 0;
   } */

typedef struct gpr_cmdline gpr_cmdline;

/** Construct a command line parser: takes a short description of the tool
   doing the parsing */
GPRAPI gpr_cmdline *gpr_cmdline_create(const char *description);
/** Add an integer parameter, with a name (used on the command line) and some
   helpful text (used in the command usage) */
GPRAPI void gpr_cmdline_add_int(gpr_cmdline *cl, const char *name,
                                const char *help, int *value);
/** The same, for a boolean flag */
GPRAPI void gpr_cmdline_add_flag(gpr_cmdline *cl, const char *name,
                                 const char *help, int *value);
/** And for a string */
GPRAPI void gpr_cmdline_add_string(gpr_cmdline *cl, const char *name,
                                   const char *help, char **value);
/** Set a callback for non-named arguments */
GPRAPI void gpr_cmdline_on_extra_arg(
    gpr_cmdline *cl, const char *name, const char *help,
    void (*on_extra_arg)(void *user_data, const char *arg), void *user_data);
/** Enable surviving failure: default behavior is to exit the process */
GPRAPI void gpr_cmdline_set_survive_failure(gpr_cmdline *cl);
/** Parse the command line; returns 1 on success, on failure either dies
   (by default) or returns 0 if gpr_cmdline_set_survive_failure() has been
   called */
GPRAPI int gpr_cmdline_parse(gpr_cmdline *cl, int argc, char **argv);
/** Destroy the parser */
GPRAPI void gpr_cmdline_destroy(gpr_cmdline *cl);
/** Get a string describing usage */
GPRAPI char *gpr_cmdline_usage_string(gpr_cmdline *cl, const char *argv0);

#ifdef __cplusplus
}
#endif

#endif /* GRPC_SUPPORT_CMDLINE_H */