utils.c

//
// Created by gosha on 15.02.2021.
//

int error(const char *msg)
{
    printf("Error: %s\n", msg);
    return -1;
}

int parse(const char *cmd, char **args)
{
    const char *p = cmd;
    int count = 0;

    for (;;) {
        while (isspace(*p)) p++;
        if (count >= 3) {
            return count;
        }
        if (*p == '\0') break;

        if (*p == '"' || *p == '\'') {
            int quote = *p++;
            const char *begin = p;

            while (*p && *p != quote) p++;
            if (*p == '\0') return error("Unmachted quote");
            strncpy(args[count], begin, p-begin);
            count++;
            p++;
            continue;
        }

        if (strchr("<>()|", *p)) {
            args[count] = calloc(1, 256);
            strncpy(args[count], p, 1);
            count++;
            p++;
            continue;
        }

        if (isalnum(*p) || *p == '.' || *p == '/') {
            const char *begin = p;

            while (isalnum(*p) || *p == '.' || *p == '/') p++;
            strncpy(args[count], begin, p-begin);
            count++;
            continue;
        }

        return error("Illegal character");
    }

    return count;
}

int check_directory(const char *path) {
    DIR *dir = opendir(path);
    if (dir) return 1;
    else return 0;
}

int startsWith(const char *str, const char *pre) {
    size_t lenpre = strlen(pre),
            lenstr = strlen(str);
    return lenstr < lenpre ? 0 : memcmp(pre, str, lenpre) == 0;
}

void append_path_part(char *path, const char *part) {
    strcat(path, "/");
    strcat(path, part);
}

char *get_line(void) {
    char *line = malloc(100), *linep = line;
    size_t lenmax = 100, len = lenmax;
    int c;

    if (line == NULL)
        return NULL;

    for (;;) {
        c = fgetc(stdin);
        if (c == EOF)
            break;

        if (--len == 0) {
            len = lenmax;
            char *linen = realloc(linep, lenmax *= 2);

            if (linen == NULL) {
                free(linep);
                return NULL;
            }
            line = linen + (line - linep);
            linep = linen;
        }

        if ((*line++ = c) == '\n')
            break;
    }
    *line = '\0';
    return linep;
}

void remove_ending_symbol(char *str, char sym) {
    for (int i = 0;; i++) {
        if (str[i] == sym)
            str[i] = 0;
        if (str[i] == 0)
            break;
    }
}

void remove_until(char *str, char sym) {
    size_t len = strlen(str);
    for (size_t i = len; i >= 0; i--) {
        if (str[i] != sym)
            str[i] = 0;
        else {
            str[i] = 0;
            break;
        }
    }
}