main.c

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

bool isFilePath(char *string){
    return access(string, F_OK) == 0 ? true : false;
}


int main(int argc, char **argv){
    char filepath[20];

    bool isFile = false;
    bool hasC = false;
    bool hasI = false;

    int searchedWordIndex;
    for (int i = 1; i < argc; i++) {
        // printf("arg: %s\n",argv[i]);
        // printf("i: %d\n",i);
        if(strcmp("-c",argv[i]) == 0){
            // puts("entrou no primeiro");
            hasC = true;
            continue;
        }
        if(strcmp("-i",argv[i]) == 0){
            // puts("entrou no segundo");
            hasI = true;
            continue;
        }
        if(isFilePath(argv[i])){
            // puts("entrou no terceiro");
            isFile = true;
            strcpy(filepath, argv[i]);
            continue;
        }
        // puts("chegou no quarto");
        searchedWordIndex = i;
    }

    int searchedWordLength = strlen(argv[searchedWordIndex]);
    char searchedWord[searchedWordLength];

    strcpy(searchedWord,argv[searchedWordIndex]);
    // printf("Palava procurada é %s na posição %d e tem tamanho %d\n",searchedWord,searchedWordIndex,searchedWordLength);

    int count = 0;
    FILE *input = stdin;
    if (isFile)
    {
        input = fopen(filepath, "r");
        if(input==NULL){
            printf("[ERRO AO ABRIR O ARQUIVO]\n");
            exit(1);
        }
    }
    char line[256];
    char loweredLine[256];
    fgets(line, sizeof(line), input);
    while (fgets(line, sizeof(line), input)) {
        strcpy(loweredLine,line);
        if (hasI)
            for (int i = 0; i < strlen(line); i++)
                loweredLine[i]=tolower(loweredLine[i]);
        // printf("Procurando em: %s",loweredLine);
        if(strstr(loweredLine, searchedWord)){
            count++;
            if(!hasC)
                printf("%s",line);
        }
    }

    if(hasC)
        printf("%d\n",count);

    if(isFile)
        fclose(input);
    return 0;
}

char *lowerString(char* text, int text_size){
    char *lowered;

    for(int i = 0; i < text_size; i++){
        lowered[i] = tolower(text[i]);
    }

    return lowered;
}