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Simple CLI flag parsing in C
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/* | |
UNLICENSE | |
This is free and unencumbered software released into the public domain. | |
Anyone is free to copy, modify, publish, use, compile, sell, or | |
distribute this software, either in source code form or as a compiled | |
binary, for any purpose, commercial or non-commercial, and by any | |
means. | |
In jurisdictions that recognize copyright laws, the author or authors | |
of this software dedicate any and all copyright interest in the | |
software to the public domain. We make this dedication for the benefit | |
of the public at large and to the detriment of our heirs and | |
successors. We intend this dedication to be an overt act of | |
relinquishment in perpetuity of all present and future rights to this | |
software under copyright law. | |
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
OTHER DEALINGS IN THE SOFTWARE. | |
For more information, please refer to <http://unlicense.org/> | |
*/ | |
#include <stddef.h> | |
#include <string.h> | |
#include <stdio.h> | |
#include "cli.h" | |
unsigned char cli_parse_flags(CliFlag flags[], | |
const size_t flags_size, | |
char *argv[], | |
const size_t argv_size) { | |
char *arg; | |
CliFlag *flag; | |
size_t idx, jdx; | |
for (idx = 0; idx < flags_size; ++idx) { | |
flag = &flags[idx]; | |
if (*flag->flag != '-') | |
continue; | |
for (jdx = 0; jdx < argv_size; ++jdx) { | |
arg = argv[jdx]; | |
if (*arg != '-' || strcmp(flag->flag, arg) != 0) | |
continue; | |
if (flag->as_switch) | |
flag->value = argv[jdx]; | |
else if (++jdx == argv_size) | |
break; | |
flag->value = argv[jdx]; | |
} | |
if (flag->required && flag->value == NULL) | |
return 0; | |
} | |
return 1; | |
} | |
void cli_print_flags(FILE *fp, | |
const CliFlag flags[], | |
const size_t flags_size, | |
const unsigned char only_required) { | |
size_t idx; | |
for (idx = 0; idx < flags_size; ++idx) { | |
if (only_required && | |
(!flags[idx].required || flags[idx].value != NULL)) { | |
continue; | |
} | |
fprintf(fp, "%s%s%s - %s\n", flags[idx].flag, | |
flags[idx].as_switch ? "" : " <value>", | |
flags[idx].required ? " (required)" : "", | |
flags[idx].description); | |
} | |
} |
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/* | |
UNLICENSE | |
This is free and unencumbered software released into the public domain. | |
Anyone is free to copy, modify, publish, use, compile, sell, or | |
distribute this software, either in source code form or as a compiled | |
binary, for any purpose, commercial or non-commercial, and by any | |
means. | |
In jurisdictions that recognize copyright laws, the author or authors | |
of this software dedicate any and all copyright interest in the | |
software to the public domain. We make this dedication for the benefit | |
of the public at large and to the detriment of our heirs and | |
successors. We intend this dedication to be an overt act of | |
relinquishment in perpetuity of all present and future rights to this | |
software under copyright law. | |
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
OTHER DEALINGS IN THE SOFTWARE. | |
For more information, please refer to <http://unlicense.org/> | |
*/ | |
#ifndef _CLI_H | |
#define _CLI_H | |
#include <stddef.h> | |
#include <stdio.h> | |
#define cli_flags(flags) flags, (sizeof(flags) / sizeof(flags[0])) | |
#define cli_argv(argv, argc) (char **)((argv) + 1), (size_t)((argc)-1) | |
#define cli_flag(flag, description, as_switch, required) \ | |
{ (flag), (description), (as_switch), (required), NULL } | |
typedef struct { | |
const char *const flag; | |
const char *const description; | |
const unsigned char as_switch; | |
const unsigned char required; | |
char *value; | |
} CliFlag; | |
unsigned char cli_parse_flags(CliFlag flags[], | |
const size_t flags_size, | |
char *argv[], | |
const size_t argv_size); | |
void cli_print_flags(FILE *fp, const CliFlag flags[], const size_t flags_size, const unsigned char only_required); | |
#endif /* _CLI_H */ |
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/* | |
UNLICENSE | |
This is free and unencumbered software released into the public domain. | |
Anyone is free to copy, modify, publish, use, compile, sell, or | |
distribute this software, either in source code form or as a compiled | |
binary, for any purpose, commercial or non-commercial, and by any | |
means. | |
In jurisdictions that recognize copyright laws, the author or authors | |
of this software dedicate any and all copyright interest in the | |
software to the public domain. We make this dedication for the benefit | |
of the public at large and to the detriment of our heirs and | |
successors. We intend this dedication to be an overt act of | |
relinquishment in perpetuity of all present and future rights to this | |
software under copyright law. | |
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
OTHER DEALINGS IN THE SOFTWARE. | |
For more information, please refer to <http://unlicense.org/> | |
*/ | |
#include <stdio.h> | |
#include "main.h" | |
#include "cli.h" | |
int main(const int argc, char *argv[]) { | |
size_t idx; | |
CliFlag flags[] = { | |
cli_flag("-hello", "The hello flag", 0, 0), | |
cli_flag("-world", "The REQUIRED world flag", 0, 1), | |
cli_flag("-yeah", "A boolean flag", 1, 0), | |
cli_flag("-run", "A REQUIRED boolean flag", 1, 1), | |
cli_flag("-help", "Print help", 1, 0), | |
}; | |
if (!cli_parse_flags(cli_flags(flags), cli_argv(argv, argc))) { | |
puts("Required flags not specified:"); | |
cli_print_flags(stdout, cli_flags(flags), 1); | |
return 1; | |
} | |
if (flags[4].value != NULL) { | |
cli_print_flags(stdout, cli_flags(flags), 0); | |
puts(""); | |
} | |
puts("Flag values:"); | |
for (idx = 0; idx < sizeof(flags) / sizeof(flags[0]); ++idx) | |
printf("%s = %s\n", flags[idx].flag, | |
flags[idx].as_switch | |
? (flags[idx].value == NULL ? "false" : "true") | |
: flags[idx].value); | |
return 0; | |
} |
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/* | |
UNLICENSE | |
This is free and unencumbered software released into the public domain. | |
Anyone is free to copy, modify, publish, use, compile, sell, or | |
distribute this software, either in source code form or as a compiled | |
binary, for any purpose, commercial or non-commercial, and by any | |
means. | |
In jurisdictions that recognize copyright laws, the author or authors | |
of this software dedicate any and all copyright interest in the | |
software to the public domain. We make this dedication for the benefit | |
of the public at large and to the detriment of our heirs and | |
successors. We intend this dedication to be an overt act of | |
relinquishment in perpetuity of all present and future rights to this | |
software under copyright law. | |
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
OTHER DEALINGS IN THE SOFTWARE. | |
For more information, please refer to <http://unlicense.org/> | |
*/ | |
#ifndef _MAIN_H | |
#define _MAIN_H | |
int main(const int, char *[]); | |
#endif /* _MAIN_H */ |
also more example usage in https://ari.lt/gh/kos :
#include <stdio.h>
#include "main.h"
#include "cli.h"
#define VERSION "44"
enum AppFlag { AppFlag_help = 0, AppFlag_count };
static CliFlag flags[AppFlag_count] = {
/* If you are not using C89: [AppFlag_help] = */ {"-help", "Print the help page", 1, 0, NULL},
};
static void print_help(FILE *fp) {
fputs("Kos version " VERSION "\nUsage: kos [flags] <command...>\n\n",
stderr);
cli_print_flags(fp, cli_flags(flags), 0);
}
int main(const int argc, char *argv[]) {
if (argc < 2) {
print_help(stderr);
return 1;
}
if (!cli_parse_flags(cli_flags(flags), cli_argv(argv, argc))) {
fputs("Flag parsing error. Are you sur4e you specified the "
"(required) flags?\n\n",
stderr);
print_help(stderr);
return 1;
}
if (flags[AppFlag_help].value != NULL) {
print_help(stdout);
return 0;
}
return 0;
}
to make it clear : use this code however you want, any license, no need for credit or anything
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you can use enums for indexing the flags, also you can add status codes instead of just 'success' and 'failure'