Options को Parse करना

#include <stdio.h>

int main(int argc, char *argv[]) {
    for (int i = 1; i < argc; i++) {
        if (argv[i][0] == '-')
            printf("option: %s\n", argv[i]);
        else
            printf("value:  %s\n", argv[i]);
    }
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    int verbose = 0;
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-v") == 0)
            verbose = 1;
    }
    printf("verbose = %d\n", verbose);
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-h") == 0 ||
            strcmp(argv[i], "--help") == 0) {
            printf("Usage: prog [options]\n");
            return 0;
        }
    }
    printf("No help requested\n");
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    const char *output = "default.txt";
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-o") == 0 && i + 1 < argc) {
            output = argv[++i];
        }
    }
    printf("Output file: %s\n", output);
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-n") == 0) {
            if (i + 1 >= argc) {
                printf("Error: -n needs a value\n");
                return 1;
            }
            printf("n = %s\n", argv[++i]);
        }
    }
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    int verbose = 0;
    const char *name = "world";
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-v") == 0) verbose = 1;
        else if (strcmp(argv[i], "-name") == 0 && i+1 < argc) name = argv[++i];
    }
    if (verbose) printf("verbose mode\n");
    printf("Hello, %s\n", name);
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    int opts_done = 0;
    for (int i = 1; i < argc; i++) {
        if (!opts_done && strcmp(argv[i], "--") == 0) {
            opts_done = 1;
            continue;
        }
        printf("%s: %s\n", opts_done ? "value" : "token", argv[i]);
    }
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    for (int i = 1; i < argc; i++) {
        if (argv[i][0] == '-') continue;
        printf("file: %s\n", argv[i]);
    }
    return 0;
}

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    for (int i = 1; i < argc; i++) {
        if (argv[i][0] != '-') continue;
        if (strcmp(argv[i], "-v") != 0)
            printf("Unknown option: %s\n", argv[i]);
    }
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char *argv[]) {
    int count = 1;
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-c") == 0 && i+1 < argc)
            count = (int) strtol(argv[++i], NULL, 10);
    }
    printf("count = %d\n", count);
    return 0;
}

#include <stdio.h>

int main(int argc, char *argv[]) {
    printf("Parsed %d tokens manually\n", argc - 1);
    return 0;
}