Possible errors when reading larger lines - c

Question

I noticed a problem with the next line while ((read = getline(&line, &len, fp)) != -1) {: I may get errors if the lines read are too large. Should I read MAXLINE pieces? I think it's a problem if I break the original line into pieces. It is possible to "cut" the fixed line in the middle of the word I am looking for.
For example, if you break the car for sale (you are looking for ) in car fo and r sale. I will not find for in either of the two pieces. Maybe a solution would be for each part read, to read extra len (search_word) characters (without changing the original place where the next piece would have started). Basically I read more r s in the first part, but it guarantees that I will find for
How can I handle possible errors?
The following program is based on the implementation of grep from linux, doing a search for several words
program:
#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;
}
}

Answer 1

The problem you describe is not present in your code precisely because you use getline() instead of fgets(). getline() reallocates the line pointer and len as required to read a full line. The only limitation is memory, which is unlikely to pose a problem on current systems.
Note however that you should close the file and free line outside of the else branch to avoid a memory leak.