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#ifndef COMMAND_H
#define COMMAND_H
#include <stdio.h>
#include "common.h"
/*
* the current command system polecat uses is simple and depends on
* int (*)(int, char**) function pointers, exactly the same as main
* because keeping track of all of those is rather tedious making
* macros was an easier solution to get rid of the redundancy
* for the sake of less readability.
* argc and argv are marked as UNUSED (defined in common.h)
* because the functions defined using this macro might not
* actually use either of them so this is required to
* supress warnings
*/
#define COMMAND(GROUP, COMMAND) \
int GROUP##_##COMMAND(UNUSED int argc, UNUSED char** argv)
/*
* all help functions in polecat look the same invoking the print_help
* helper function defined in common.c with the command groups list
* of available commands.
* This also exists to reduce redundancy.
*/
#define COMMAND_HELP(GROUP, MSG) \
COMMAND(GROUP, help) \
{ \
fprintf(stderr, USAGE_STR MSG " <command>\n"); \
print_help(GROUP##_commands, ARRAY_LEN(GROUP##_commands), GROUP##_flags, ARRAY_LEN(GROUP##_flags)); \
return 0; \
}
/*
* This is the same as the COMMAND macro except dedicated to the actual
* command group name, which is the thing called from the actual main
* function.
*/
#define COMMAND_GROUP(GROUP) \
int GROUP(int argc, char** argv)
/*
* the body is split up so we can construct our own group function for
* e.g. ARGV0 parsing
*/
#define COMMAND_GROUP_BODY(GROUP) \
if (argc > 1) \
{ \
for (unsigned long i = 0; i < ARRAY_LEN(GROUP##_commands); ++i) \
if (!strcmp(GROUP##_commands[i].name, argv[1])) return GROUP##_commands[i].func(argc-1, argv+1); \
\
for (int j = 1; j < argc; ++j) \
{ \
if (argv[j][0] != '-') continue; \
\
for (unsigned long i = 0; i < ARRAY_LEN(GROUP##_flags); ++i) \
{ \
if ((GROUP##_flags[i].variant & ONE && argv[j][1] == GROUP##_flags[i].name[0]) || \
(GROUP##_flags[i].variant & TWO && argv[j][1] == '-' \
&& !strcmp(GROUP##_flags[i].name, argv[j]+2))) \
{ \
return GROUP##_flags[i].func(0, NULL); \
} \
} \
} \
\
fprintf(stderr, NAME ": '%s' is not a command or flag\n", argv[1]); \
return 0; \
} \
return GROUP##_help(argc-1, argv+1);
/*
* the main command group function is only suppose to find given command
* by the name and then invoke it.
*
* If the desired command is not found we should tell the user that.
*
* If no command is provided we should just print the list of commands by
* calling the groups help command.
*/
#define COMMAND_GROUP_FUNC(GROUP) \
COMMAND_GROUP(GROUP) \
{ \
COMMAND_GROUP_BODY(GROUP) \
} \
#endif
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