s21_cat.c

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

void open_file(char** argv, int flag_b, int flag_e, int flag_n, int flag_s,
               int flag_t, int flag_T, int flag_E);
int s21_cat(int flag_b, int flag_e, int flag_n, int flag_s,
            int flag_t, int flag_T, int flag_E, FILE* fp, int count);
int flag_to_int(char* flags, char flag);

int flag_to_int(char* flags, char flag) {
    int tmp = 0;
    for (int i = 0; i < strlen(flags); i++) {
        if (flags[i] == flag) {
            tmp = 1;
            break;
        }
    }
    return tmp;
}

int s21_cat(int flag_b, int flag_e, int flag_n, int flag_s,
            int flag_t, int flag_T, int flag_E, FILE* fp, int count) {
    int current, prev = '\n';
    int temp = 0;
    while ((current = getc(fp)) != EOF) {
        if (flag_s) {
            if (current == '\n') temp++;
            if (current != '\n') temp = 0;
        }
        if (flag_b && temp < 3) {
            if ((prev == '\n' && !(current == '\n')) || count == 1) {
                printf("%6d\t", count);
                count++;
            }
        }
        if (flag_n && !flag_b && temp < 3) {
            if (prev == '\n' || count == 1) {
                printf("%6d\t", count);
                count++;
            }
        }
        if (flag_E || flag_e && temp < 3) {
            if ((flag_t || flag_e) && current >= 0 && current < 32 && current != '\n' && current != '\t') {
                printf("^%c", 64 + current);
            } else if ((flag_t || flag_T) && current == '\t') {
                printf("^I");
            } else if (current != '\n') {
                printf("%c", current);
            }
            if (current == '\n') {
                printf("$\n");
            }
            if (current != '\n') temp = 0;
        } else if (flag_T || flag_t && temp < 3) {
            if (!flag_e && flag_t && current >= 0 && current < 32 && current != '\n' && current != '\t') {
                printf("^%c", 64 + current);
            } else if (current != '\t' && current != '\n') {
                printf("%c", current);
            } else if (!flag_e && !flag_E && current == '\n') {
                printf("\n");
            }
            if (current == '\t') {
                printf("^I");
            }
            if (current != '\n') temp = 0;
        } else {
            if (!((flag_e || flag_E) && current == '\n') && temp < 3) {
                putchar(current);
            }
        }
        prev = current;
    }
    return count;
}

void open_file(char** argv, int flag_b, int flag_e, int flag_n,
               int flag_s, int flag_t, int flag_T, int flag_E) {
    FILE* fp;
    argv++;
    int result = 1;
    while (*argv) {
        if (*argv[0] == '-') {
            argv++;
        } else {
            if ((fp = fopen(*argv, "r")) == NULL) {
                argv++;
            } else {
                result = s21_cat(flag_b, flag_e, flag_n, flag_s, flag_t, flag_T, flag_E, fp, result);
                argv++;
            }
        }
    }
}

int main(int argc, char** argv) {
    int flag_b = 0, flag_e = 0, flag_n = 0, flag_s = 0, flag_t = 0, flag_E = 0, flag_T = 0;
    int i = 0;
    while (i < argc) {
        if (argv[i][0] == '-' && argv[i][1] != '-') {
            flag_b = flag_b == 1 ? 1 : flag_to_int(argv[i], 'b');
            flag_e = flag_e == 1 ? 1 : flag_to_int(argv[i], 'e');
            flag_n = flag_n == 1 ? 1 : flag_to_int(argv[i], 'n');
            flag_s = flag_s == 1 ? 1 : flag_to_int(argv[i], 's');
            flag_t = flag_t == 1 ? 1 : flag_to_int(argv[i], 't');
            flag_E = flag_E == 1 ? 1 : flag_to_int(argv[i], 'E');
            flag_T = flag_T == 1 ? 1 : flag_to_int(argv[i], 'T');
        }
        if (argv[i][0] == '-' && argv[i][1] == '-') {
            if (strcmp(&argv[i][0], "--number") == 0) flag_n = 1;
            if (strcmp(&argv[i][0], "--number-nonblank") == 0) flag_b = 1;
            if (strcmp(&argv[i][0], "--squeeze-blank") == 0) flag_s = 1;
        }
        i++;
    }
    open_file(argv, flag_b, flag_e, flag_n, flag_s, flag_t, flag_T, flag_E);
    return 0;
}