Answer by Harith for Library for managing CLI flags

The pragma directive is non-portable:

Though supported by most modern compilers, it is not standard C.Consider using include guards:

// #pragma once#ifndef FLAGUTIL_H#define FLAGUTIL_H...#endif /* FLAGUTIL_H */

Avoid using magic numbers:

// Why 100?char name[100];

Perhaps defined a named constant:

#define MAX_NAME_LEN 100char name[MAX_NAME_LEN];

The functions that should not be visible outside of a translation unit should be declared as having internal linkage:

#if 0    // It is rather pointless to specify 'signed' here.     char *flag_nextarg(signed int argc, char **argv) #else     static char *flag_nextarg(int argc, char **argv) #endif

Calculate the length once:

#if 0    for(char **cur_flag = argv; cur_flag < argv + argc; cur_flag++) {        if(strncmp(flag, *cur_flag, strlen(flag)) == 0 && (*(*cur_flag + strlen(flag)) == '=' || *(*cur_flag + strlen(flag)) == '\0')) {            present = true;        }    }#else     for(char **cur_flag = argv; cur_flag < argv + argc; cur_flag++) {        const size_t flag_len = strlen(flag);        if(strncmp(flag, *cur_flag, flag_len) == 0 && (*(*cur_flag + flag_len) == '=' || *(*cur_flag + flag_len) == '\0')) {            present = true;        }    }#endif

Do we need to continue searching once we have found a match? Can we not simply return true? That would also eliminate the need for present.

Similarly, in flag_get(), calculate the length of flag once.

Send error messages to stderr:

if(*flag != '-' || !(*(flag + 1))) {#if 0            printf("Invalid flag structure for flag " bold("%s") " passed to get_flag.\n", flag);#else    fprintf(stderr, "Invalid flag structure for flag " bold("%s") " passed to get_flag.\n", flag);#endif    return NULL;}

See: stderr.