grep implementation for multi-word search - c

Question

I wrote a program that implements the grep command. I tried to search by several words. I use the -e WORD option to search by word in the target file, so if the option is present several times in the command line you can search for more words grep will display any line that contains at least one searched word.
I would like you to criticize the implementation of this option (-e WORD). What possible problems may arise?
Something tells me that I could have implemented it even better
I think the treatment of this grep option could have been better written
code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char** argv){
if(argc < 3) {
printf("Usages:\n1: ./grep.o <word> <file>\n2: ./grep.o -e <word> [-e <word>...] <file>\n");
return 1;
}
else {
FILE* fp;
char* line = NULL;
size_t len = 0;
ssize_t read;
int i;
fp = fopen(argv[argc - 1], "r");
if(fp == NULL) {
printf("File doesn't exist or cannot be read!\n");
return 1;
}
if(argc == 3) {
while((read = getline(&line, &len, fp)) != -1) {
if(strstr(line, argv[1]) != NULL)
printf("%s", line);
}
}
else {
for(i = 1; i < argc - 2; i += 2) {
if(strcmp(argv[i],"-e") != 0) {
printf("The option must be \"-e\"!\n");
fclose(fp);
return 1;
}
}
if(i + 1 == argc - 1) {
if(strcmp(argv[i],"-e") != 0) {
printf("The option must be \"-e\"!\n");
}
else {
printf("The option must have a word after it!\n");
}
fclose(fp);
return 1;
}
while((read = getline(&line, &len, fp)) != -1) {
for(i = 1; i < argc - 2; i += 2) {
if(strstr(line, argv[i + 1]) != NULL) {
printf("%s", line);
break;
}
}
}
fclose(fp);
if(line)
free(line);
}
return 0;
}
}