main.c

#include <limits.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "list.h"
#include "tree.h"
#include "exec.h"

// если поставить в дебаг 1, то шелл будет считывать команды из фаила, указанного в мейн'е
#define DEBUG 0

#define BUFFER_SIZE 1
#define f_ORDINARY_WORK 0
#define f_END_OF_FILE 1
#define f_END_OF_LINE 2
#define f_INCORRECT_INPUT 3

#define MAX_PATH 32


#if DEBUG == 1
FILE *f;
#define PATH f
#else
#define PATH stdin
#endif

char special_symbols[] = {'|', '&', ';', '>', '<', '(', ')'};

int in(char symbol, char *mas) // проверяет вхождение символа в массив
{
    for (int i = 0; i < strlen(mas); i++)
        if (symbol == mas[i])
            return 1;
    return 0;
}

void add_char_to_end(char symbol, char *word) // добавление символа в строку
{
    size_t length = strlen(word);
    word[length] = symbol;
    word[length + 1] = '\0';
}

char *get_string(short *const flag)
{
    static int i = BUFFER_SIZE, end_of_sequence = BUFFER_SIZE;
    static char *buf, buf_initialized = 0, flag_of_EOF = 0, *tmp0;

    if (flag_of_EOF == 1)
    {
        flag_of_EOF = 0;
        free(buf);
        buf_initialized = 0;
        i = BUFFER_SIZE;
        end_of_sequence = BUFFER_SIZE;
        *flag = f_END_OF_FILE;
        return NULL;
    }
    if (!buf_initialized)
    {
        tmp0 = malloc(BUFFER_SIZE * sizeof(char) + 1);
        if (tmp0 != NULL)
            buf = tmp0;
        else
        {
            fprintf(stderr, "Seg. fault");
            /*delete_list(tree);
            delete_tree(unit);*/
            return 0;
        }
        //buf = malloc(BUFFER_SIZE * sizeof(char) + 1); //for '\0'
        buf_initialized = 1;
    }
    size_t word_size = BUFFER_SIZE * sizeof(char);
    char *word = malloc(word_size + 1), *tmp; //for '\0'
    word[0] = '\0';

    int quote_flag = 0;
    int slash_flag = 0;

    for (;; i++)
    {
        if (i >= BUFFER_SIZE)
        {
            buf[0] = '\0';
            end_of_sequence = (int) fread(buf, sizeof(char), BUFFER_SIZE, PATH);
            if (end_of_sequence < BUFFER_SIZE)
            {
                buf[end_of_sequence] = '\0';
                add_char_to_end('\n', buf);
                *flag = f_END_OF_FILE;
            }
            i = 0;
        }
        size_t w_length = strlen(word);
        if (w_length == word_size)
        {
            tmp = realloc(word, word_size + BUFFER_SIZE * sizeof(char) + 1);
            if (tmp != NULL)
                word = tmp;
            else
            {
                fprintf(stderr, "Seg. fault");
                /*delete_list(tree);
                delete_tree(unit);*/
                return 0;
            }
            //word = realloc(word, word_size + BUFFER_SIZE * sizeof(char) + 1);//for '\0'
            word_size += BUFFER_SIZE * sizeof(char);
        }
        if (slash_flag == 1)
        {
            add_char_to_end(buf[i], word);
            slash_flag = 0;
            continue;
        }
        switch (buf[i])
        {
        case '"':
            if (quote_flag == 1)
            {
                i++;
                return word;
            }
            quote_flag = 1;
            continue;

        case '\\':
            slash_flag = 1;
            continue;

        case '|':
        case '&':
        case '>':
            if ((w_length == 0) || ((word[w_length - 1] == buf[i]) && (w_length == 1)))
                add_char_to_end(buf[i], word);
            else
            {
                if (quote_flag == 1)
                    continue;
                *flag = f_ORDINARY_WORK;
                return word;
            }
            break;
        case ';':
        case '<':
        case '(':
        case ')':
            if (w_length == 0)
                add_char_to_end(buf[i], word);
            else
            {
                if (quote_flag == 1)
                    continue;
                *flag = f_ORDINARY_WORK;
                return word;
            }
            break;
        case 'a'...'z':
        case 'A'...'Z':
        case '0'...'9':
        case ':':
        case '_':
        case '$':
        case '/':
        case '.':
        case '-':
            if ((w_length == 0) || (in(word[w_length - 1], special_symbols) == 0))
                add_char_to_end(buf[i], word);
            else
            {
                if (quote_flag == 1)
                    continue;
                *flag = f_ORDINARY_WORK;
                return word;
            }
            break;
        case ' ':
        case '\t':
            if (w_length == 0)
                continue;
            else
            {
                if (quote_flag == 1)
                {
                    add_char_to_end(buf[i], word);
                    continue;
                }
                *flag = f_ORDINARY_WORK;
                return word;
            }
        case '\n':
            if (quote_flag != 1)
            {
                if (*flag == f_END_OF_FILE)
                {
                    free(buf);
                    buf_initialized = 0;
                    i = BUFFER_SIZE;
                    end_of_sequence = BUFFER_SIZE;
                }
                else
                {
                    *flag = f_END_OF_LINE;
                    i++;
                }
                if (w_length == 0)
                {
                    free(word);
                    return NULL;
                }
                return word;
            }
        case '#':
#if DEBUG == 0
            if (quote_flag != 1)
            {
                while ((buf[i] != '\n') && (i != end_of_sequence))
                    i++;
                if (i == end_of_sequence)
                {
                    int c;
                    do
                        c = fgetc(stdin);
                    while ((c != '\n') && (c != EOF));
                    if (c == EOF)
                        flag_of_EOF = 1;
                }
                *flag = f_END_OF_LINE;
                return word;
            }
#else
            printf("comment was met\n");
#endif
        // error
        default:

#if DEBUG == 0
            while ((buf[i] != '\n') && (i != end_of_sequence))
                i++;
            if (i == end_of_sequence)
            {
                int c;
                do
                    c = fgetc(stdin);
                while ((c != '\n') && (c != EOF));
                if (c == EOF)
                    flag_of_EOF = 1;
            }
            *flag = f_INCORRECT_INPUT;
#else
            printf("error\n");
            *flag = f_END_OF_FILE;
#endif
            free(word);
            return NULL;
        }
    }
}

char *dollar_sign_handler(char *string) // замена переменных окржения
{
    char *tmp;
    if (string[0] != '$')
        return string;
    tmp = realloc(string, MAX_PATH);
    if (tmp == NULL)
    {
        fprintf(stderr, "Seg. fault");
        /*delete_list(tree);
        delete_tree(init);*/
        return 0;
    }
    else
    {
        if (!strcmp(string, "$HOME"))
        {
            string = realloc(string, MAX_PATH);
            strcpy(string, getenv("HOME"));
        }
        else if (!strcmp(string, "$SHELL"))
        {
            string = realloc(string, MAX_PATH);
            getcwd(string, PATH_MAX + 1);
        }
        else if (!strcmp(string, "$USER"))
        {
            string = realloc(string, MAX_PATH);
            strcpy(string, getenv("LOGNAME"));
        }
        else if (!strcmp(string, "$EUID"))
        {
            string = realloc(string, MAX_PATH);
            sprintf(string, "%d", getuid());
        }
    }
    return string;
}

void handler(string_list unit)
{
    if (unit == 0)
        return;
    if (check_brace(unit))
    {
        printf("incorrect braces\n");
        return;
    }
    struct cmd_inf *tree = list_to_tree(unit);
    //print_list(unit);
    //print_tree(tree, 0);
    tree_handler(tree);
    delete_tree(tree);
    delete_list(unit);
}

// приглашение ко вводу
void invitation()
{
    printf("\n");
    printf("%s", "\x1b[32m"); /*здесь изменяется цвет на зеленый */
    char s[100]; /* ограничение: имя хоста и текущей директории не должно быть слишком длинным! */
    gethostname(s, 100);
    printf("%s@%s", getenv("USER"), s);
    printf("%s", "\033[01;33m"); /* здесь изменяется цвет на желтый */
    getcwd(s, 100);
    printf(":%s$ ", s);
    printf("%s", "\033[01;37m"); // белый
}

// тут собираются команды одной строки и запускается обработчик списка команд
int main()
{

#if DEBUG == 1
    f = fopen("/home/kirson/tasks/task_5/try_5", "r");
#endif
    signal(SIGINT, SIG_IGN);

    short flag = f_ORDINARY_WORK;
    while (flag != f_END_OF_FILE)
    {
        invitation();
#if DEBUG == 1
        printf("\n");
#endif
        string_list array = 0;
        char *string;

        while (1)
        {
            string = get_string(&flag);
            if (string != NULL)
                add_to_string(&array, dollar_sign_handler(string));
            if (flag == f_END_OF_LINE)
            {
                handler(array);
                break;
            }
            else if (flag == f_END_OF_FILE)
            {
                handler(array);
                break;
            }
            else if (flag == f_INCORRECT_INPUT)
            {
                printf("Incorrect input :( \nPlease check your sequence of symbols and try again\n");
                delete_list(array);
                break;
            }
        }
    }
#if DEBUG == 1
    fclose(f);
#endif
}